A
acbern@gmx.de
Wed, Aug 27, 2014 12:41 AM
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only there many subsequent measuremnts with statistics make sense) I am already getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal) unless the amb. temperature is really very stable (half a degree already adds about 0.25ppm at 10v)
thanks
Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete? In the
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one particular
case, I am taking a 100 readings with NLPC set for 1000 so its a long while
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans randyevans2688@gmail.com
wrote:
Bill,
I am trying to figure out the MATH function without much success. I input
the sequence you said (I looked up the instructions to understand what you
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG 4;TRIG; and
it shows up on the display when I input BLUE F1. I hit ENTER and it takes
the 40 measurements and the MATH symbol shows on the display during the
measurements. After the SMPL symbol no longer blinks I hit MATH 2 and I
get a MATH ERR symbol on the display. I tried it a couple of times and the
same result so I am doing something wrong. Is there a better source for
explaining how to do front panel masurements than the User Guide, which
seems oriented at programming automatic rather than manual measurements.
Randy
On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold wpgold3637@att.net wrote:
Randy:
The MATH function is accessible from the keypad. I don't have an IEEE
interface right now that works. You can also program the numeric keypad
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona #4892
banana plugs and Belden #9272 wire. Why 9272, because it was handy at the
time. It is tin plated copper, shielded twisted pair 20 ga. I have plans
to do custom cables with 16 ga. bare copper wire that I will twist and
then
put a braided shield over it. I simply cannot find what I want so I will
build my own cable. I have done something like this before and it worked
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I have
used
in the past to verify my homemade "low thermal" leads as described above.
Frankly I cannot see any difference between using the 1756 cables and my
homemade cables once I give them a few minutes for the thermals to go
away.
As far as I can tell and measure the differences, if any, are below 0.1
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A are all
adjustable you may be seeing a misadjusted 1 volt from the 732A. As far
as
the instability of the readings it is hard to determine which is causing
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with the
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this does is
set
the MATH to "Statistics" (store high reading/low reading/ and mean of the
readings) in the registers, the number of readings to "40", the trigger to
"hold" (which keeps the meter from triggering until I press "ENTER" and
then
trigger the sequence of 40 readings when I push the "ENTER" button. You
can
do all of this manually from the keypads but since I use this sequence a
lot
I have preprogrammed it. This is after I set digits to "8" and PLC to
100.
Once those 40 readings are finished then you can access the various MATH
statistic registers, using the menu, by entering "MATH" and then a 2 for
low, a 4 for mean, and 13 for high. Of course you could do all of this
through the IEEE also. The 3458A has a very rich set of measurement
commands. I am still learning all of them. It depends upon what I am
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived from
resistive dividers from the 10 volt, I don't see how they could contribute
to the varying readings you are measuring. I think I would put a short on
the input of the 3458A and manually set the range to 1 volt and then
observe
the variations that way without the 732A involved. When I do this I see a
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the low
side
of the measurment terminals, GUARD connected doesn't seem to affect the
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt output I
got
a variation of 0.159 uVolts using the same 40 reading method above. I
would
use this to determine where your problem might exist. Just having the
meter
input shorted will point you in the right direction. Meter, cables or
732A.
Sorry for the long dissertation. Friends get mad at me for being so
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to thermals.
If I move the cables (with gold-plated banana plugs) using a small
rather than letting my hand touch the plugs, it is much more stable.
then hold the banana plug with my hand after the reading has stabilized,
the reading drifts rapidly upward. I am trying to check the stability
the reading but I haven't figured out the MATH function yet. I assume
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using NLPC of
and 1000) is much greater than what you are measuring on your system.
sure how to ascertain if it's the 3458A or the 732. The value of the
readings are very different between the two - the 3458 reads about 50 uV
high on the 10 V output and about 12 uV low on the 1V output. Rather
differences (this is after an ACAL). I need to find some better cables
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net wrote:
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they will fit
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic LC-R064R5C and
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very common
as
it is used in a lot of "EXIT" signs so they are lighted when the power
out. I don't see how the 12V 7AH will fit as they are too large. I
you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6 volt
but the terminals are in the wrong place so you will have to "nibble"
the aluminum plate that holds them in the 732A battery pack. You have
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with the 6V
New batteries will last around 12 to 14 hours before the "CAL" light
out when AC power is not applied. So shipping to Cal Lab can be a
if it is a distance away, or you have to use a shipper like UPS or
and
you ship the night before and then use their "Morning delivery" and
Lab is expecting your 732A. Same on the way back to you. Of course
could always strap another battery on the 732A and hook it up to the
power" plug to last longer. I have seen it done. The issue is to get
Cal Lab to charge the extra battery before they ship the 732A back to
When you remove and work on the battery pack always have the AC
plugged in. The "CAL" led will stay on because the 18.6 v regulated
is working.
The "CAL" light is to indicate that power has not been lost to the
Reference Amp or other associated circuits. When the raw supply
voltage drops below about 21 volts the "CAL" light will go out. Below
voltage the heater circuits will not work correctly and the 18.6 volt
regulated supply will not regulate. The requirement is that the
Amp be kept "alive" at all times to maintain the output voltage that
measured at the time of the most recent Calibration or Certification.
the semiconductor junctions are unbiased and cool off when power is
and then power is restored the result will be a different 10 volts
before the power failure. My experience is that after all of the
that
these units have been powered up, this won't happen and when power is
and then restored, even months later, the 732A will come back to
exactly the same 10 volts as when they lost power, usually with in 0.2
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the 1 volt
output? What is the PLC set to? I always use 100 PLC to measure
you don't have "low thermal" connection leads you can experience uV
for a minute or more after plugging in the leads due to the "thermals"
generated because of the difference in temperature between the banana
on the 732A and the banana plugs of the leads. I have found that even
plugging in the lead will generate a thermal difference because of
difference of temps and some heating due to the physical act of just
inserting the plug because of friction between the jack and plug (my
at any rate). You have to allow at least a minute or more before
able
to make a measurement after plugging in the leads. I just measured
variation of the 1 volt output of my 732A and using my 3458A and I
total difference of 0.159 uV over 40 measurements using 100 PLC on
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH batteries
keep topped off and they have very low current draw (~2 to 3 mA at
VDC) when charged and at their float voltage, so I am pretty sure
in good condition. I will look at getting those in the units after
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a 732A
slightly disagree. I am like the man with two watches that disagree
time - which is correct? For the moment, i am only concerned with
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <tmicallef@gmail.com
Randy,
You have two possible choices. It can be configured with 4 x 6v
batteries or 2 x 12v 7Ah batteries. Hopefully the previous owner
modified the battery pack already. A couple of mine needed a
to remove enough of the aluminum cover that fits over the tops of
batteries. The original cover will short out to the battery tabs
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you slightly
battery life. I lost a couple sets of mail-order batteries after a
extended outages. I would recommend going with locally bought
instead of the cheaper mail order. My local Batteries Plus will
have some warranty if I remember correctly. Moving forward I will
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap batteries did
discharge equally, and would not recover when power was applied.
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all the
the pre-regulator and regulator boards. My feeling is that once
online, they should run as long as possible between repairs.
The battery charger circuit may need adjusting. I tweaked mine and
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but it needs
batteries. Any suggestions for sources (I haven't opened up the
I want to make sure it works before doing that). Also received
ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL ran
program to get the CAL data from my 3458A. Should be a busy
and follow the instructions there.
and follow the instructions there.
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only there many subsequent measuremnts with statistics make sense) I am already getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal) unless the amb. temperature is really very stable (half a degree already adds about 0.25ppm at 10v)
thanks
> Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> Von: "Randy Evans" <randyevans2688@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] 732A and Prologix received
>
> Is there any way to tell when the function key routine is complete? In the
> case of taking multiple readings using the DEFKEY and MATH function, I
> don't see any indication when the routine is complete. In one particular
> case, I am taking a 100 readings with NLPC set for 1000 so its a long while
> before it's complete, but i have to guess when it's done.
>
> Thanks,
>
> Randy
>
>
> On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <randyevans2688@gmail.com>
> wrote:
>
> > Bill,
> >
> > I am trying to figure out the MATH function without much success. I input
> > the sequence you said (I looked up the instructions to understand what you
> > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG 4;TRIG; and
> > it shows up on the display when I input BLUE F1. I hit ENTER and it takes
> > the 40 measurements and the MATH symbol shows on the display during the
> > measurements. After the SMPL symbol no longer blinks I hit MATH 2 and I
> > get a MATH ERR symbol on the display. I tried it a couple of times and the
> > same result so I am doing something wrong. Is there a better source for
> > explaining how to do front panel masurements than the User Guide, which
> > seems oriented at programming automatic rather than manual measurements.
> >
> > Randy
> >
> >
> >
> > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net> wrote:
> >
> >> Randy:
> >>
> >> The MATH function is accessible from the keypad. I don't have an IEEE
> >> interface right now that works. You can also program the numeric keypad
> >> keys to have preprogrammed functions. DEFKEY
> >>
> >> I have made my own "low thermal" measurement leads from Pomona #4892
> >> banana plugs and Belden #9272 wire. Why 9272, because it was handy at the
> >> time. It is tin plated copper, shielded twisted pair 20 ga. I have plans
> >> to do custom cables with 16 ga. bare copper wire that I will twist and
> >> then
> >> put a braided shield over it. I simply cannot find what I want so I will
> >> build my own cable. I have done something like this before and it worked
> >> fine. When I get a "round toit".
> >>
> >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I have
> >> used
> >> in the past to verify my homemade "low thermal" leads as described above.
> >> Frankly I cannot see any difference between using the 1756 cables and my
> >> homemade cables once I give them a few minutes for the thermals to go
> >> away.
> >> As far as I can tell and measure the differences, if any, are below 0.1
> >> ppm
> >> at 10 volts.
> >>
> >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A are all
> >> adjustable you may be seeing a misadjusted 1 volt from the 732A. As far
> >> as
> >> the instability of the readings it is hard to determine which is causing
> >> the
> >> problem. I have programed (DEFKEY) a numeric keypad key #1 with the
> >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this does is
> >> set
> >> the MATH to "Statistics" (store high reading/low reading/ and mean of the
> >> readings) in the registers, the number of readings to "40", the trigger to
> >> "hold" (which keeps the meter from triggering until I press "ENTER" and
> >> then
> >> trigger the sequence of 40 readings when I push the "ENTER" button. You
> >> can
> >> do all of this manually from the keypads but since I use this sequence a
> >> lot
> >> I have preprogrammed it. This is after I set digits to "8" and PLC to
> >> 100.
> >> Once those 40 readings are finished then you can access the various MATH
> >> statistic registers, using the menu, by entering "MATH" and then a 2 for
> >> low, a 4 for mean, and 13 for high. Of course you could do all of this
> >> through the IEEE also. The 3458A has a very rich set of measurement
> >> commands. I am still learning all of them. It depends upon what I am
> >> trying to accomplish.
> >>
> >> Since the 1.018 and 1.0 volt outputs are passive and derived from
> >> resistive dividers from the 10 volt, I don't see how they could contribute
> >> to the varying readings you are measuring. I think I would put a short on
> >> the input of the 3458A and manually set the range to 1 volt and then
> >> observe
> >> the variations that way without the 732A involved. When I do this I see a
> >> variation from low reading to high reading of 0.125 uVolts and then
> >> another
> >> 40 I get 0.155 uVolts. This is without the GUARD connected to the low
> >> side
> >> of the measurment terminals, GUARD connected doesn't seem to affect the
> >> readings. So that is the base noise of the 3458A without the 732A,
> >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt output I
> >> got
> >> a variation of 0.159 uVolts using the same 40 reading method above. I
> >> would
> >> use this to determine where your problem might exist. Just having the
> >> meter
> >> input shorted will point you in the right direction. Meter, cables or
> >> 732A.
> >>
> >> Sorry for the long dissertation. Friends get mad at me for being so
> >> detailed sometimes.
> >>
> >> Bill
> >>
> >> ----- Original Message -----
> >> From: "Randy Evans" <randyevans2688@gmail.com>
> >> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> Sent: Sunday, August 24, 2014 7:22 AM
> >> Subject: Re: [volt-nuts] 732A and Prologix received
> >>
> >>
> >> > Bill,
> >> >
> >> > I have convinced myself that the problem I an seeing is due to thermals.
> >> > If I move the cables (with gold-plated banana plugs) using a small
> >> towel
> >> > rather than letting my hand touch the plugs, it is much more stable.
> >> If I
> >> > then hold the banana plug with my hand after the reading has stabilized,
> >> > the reading drifts rapidly upward. I am trying to check the stability
> >> of
> >> > the reading but I haven't figured out the MATH function yet. I assume
> >> this
> >> > is a programmed function using GPIB only?
> >> >
> >> > The stability I am seeing by manually recording readings (using NLPC of
> >> 100
> >> > and 1000) is much greater than what you are measuring on your system.
> >> Not
> >> > sure how to ascertain if it's the 3458A or the 732. The value of the
> >> > readings are very different between the two - the 3458 reads about 50 uV
> >> > high on the 10 V output and about 12 uV low on the 1V output. Rather
> >> large
> >> > differences (this is after an ACAL). I need to find some better cables
> >> to
> >> > make sure the errors are not due to thermals again.
> >> >
> >> > Randy
> >> >
> >> >
> >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net> wrote:
> >> >
> >> > > Randy:
> >> > >
> >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they will fit
> >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic LC-R064R5C and
> >> > > others
> >> > > that are in this size and package. Order from one of the usual
> >> electronics
> >> > > distributors like Allied, Mouser, Digikey. This is a very common
> >> battery
> >> > > as
> >> > > it is used in a lot of "EXIT" signs so they are lighted when the power
> >> goes
> >> > > out. I don't see how the 12V 7AH will fit as they are too large. I
> >> guess
> >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6 volt
> >> 4
> >> AH
> >> > > but the terminals are in the wrong place so you will have to "nibble"
> >> out
> >> > > the aluminum plate that holds them in the 732A battery pack. You have
> >> to
> >> > > be
> >> > > careful if you use the 12v 5AH as you will have 4 extra battery
> >> connection
> >> > > leads to deal with and connect correctly. I would stick with the 6V
> >> 4AH.
> >> > > New batteries will last around 12 to 14 hours before the "CAL" light
> >> goes
> >> > > out when AC power is not applied. So shipping to Cal Lab can be a
> >> problem
> >> > > if it is a distance away, or you have to use a shipper like UPS or
> >> FEDEX
> >> > > and
> >> > > you ship the night before and then use their "Morning delivery" and
> >> the
> >> Cal
> >> > > Lab is expecting your 732A. Same on the way back to you. Of course
> >> you
> >> > > could always strap another battery on the 732A and hook it up to the
> >> "ext
> >> > > power" plug to last longer. I have seen it done. The issue is to get
> >> the
> >> > > Cal Lab to charge the extra battery before they ship the 732A back to
> >> you.
> >> > >
> >> > > When you remove and work on the battery pack always have the AC
> >> power
> >> > > plugged in. The "CAL" led will stay on because the 18.6 v regulated
> >> supply
> >> > > is working.
> >> > >
> >> > > The "CAL" light is to indicate that power has not been lost to the
> >> > > Reference Amp or other associated circuits. When the raw supply
> >> (battery)
> >> > > voltage drops below about 21 volts the "CAL" light will go out. Below
> >> that
> >> > > voltage the heater circuits will not work correctly and the 18.6 volt
> >> > > regulated supply will not regulate. The requirement is that the
> >> Reference
> >> > > Amp be kept "alive" at all times to maintain the output voltage that
> >> was
> >> > > measured at the time of the most recent Calibration or Certification.
> >> When
> >> > > the semiconductor junctions are unbiased and cool off when power is
> >> lost,
> >> > > and then power is restored the result will be a different 10 volts
> >> than
> >> > > before the power failure. My experience is that after all of the
> >> years
> >> > > that
> >> > > these units have been powered up, this won't happen and when power is
> >> lost
> >> > > and then restored, even months later, the 732A will come back to
> >> almost
> >> > > exactly the same 10 volts as when they lost power, usually with in 0.2
> >> PPM
> >> > > after 24 hours of "warm up".
> >> > >
> >> > > What type of hookup leads are you using when measuring the 1 volt
> >> > > output? What is the PLC set to? I always use 100 PLC to measure
> >> this.
> >> If
> >> > > you don't have "low thermal" connection leads you can experience uV
> >> changes
> >> > > for a minute or more after plugging in the leads due to the "thermals"
> >> > > generated because of the difference in temperature between the banana
> >> jacks
> >> > > on the 732A and the banana plugs of the leads. I have found that even
> >> just
> >> > > plugging in the lead will generate a thermal difference because of
> >> > > difference of temps and some heating due to the physical act of just
> >> > > inserting the plug because of friction between the jack and plug (my
> >> theory
> >> > > at any rate). You have to allow at least a minute or more before
> >> being
> >> > > able
> >> > > to make a measurement after plugging in the leads. I just measured
> >> the
> >> > > variation of the 1 volt output of my 732A and using my 3458A and I
> >> got a
> >> > > total difference of 0.159 uV over 40 measurements using 100 PLC on
> >> the
> >> 1
> >> > > volt range of the 3458A. Using the MATH function and all of the data
> >> you
> >> > > can collect. That was after waiting for several minutes after
> >> plugging
> >> in
> >> > > the leads.
> >> > >
> >> > > I hope all of this helps.
> >> > >
> >> > > Bill
> >> > >
> >> > >
> >> > >
> >> > > ----- Original Message -----
> >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> >> > > To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> > > Sent: Friday, August 22, 2014 9:03 PM
> >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> >> > >
> >> > >
> >> > > > Todd,
> >> > > >
> >> > > > Thanks for the info. I have several Panasonic 12V 7 AH batteries
> >> that
> >> I
> >> > > > keep topped off and they have very low current draw (~2 to 3 mA at
> >> 13.5
> >> > > > VDC) when charged and at their float voltage, so I am pretty sure
> >> they
> >> > > are
> >> > > > in good condition. I will look at getting those in the units after
> >> I
> >> > > > ascertain the condition of the 732.
> >> > > >
> >> > > > So now I have a what appears to be a functioning 3458A and a 732A
> >> but
> >> > > they
> >> > > > slightly disagree. I am like the man with two watches that disagree
> >> on
> >> > > the
> >> > > > time - which is correct? For the moment, i am only concerned with
> >> > > > stability. The need for absolute accuracy will come later.
> >> > > >
> >> > > > Randy
> >> > > >
> >> > > >
> >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <tmicallef@gmail.com
> >> >
> >> > > wrote:
> >> > > >
> >> > > > > Randy,
> >> > > > >
> >> > > > > You have two possible choices. It can be configured with 4 x 6v
> >> 4Ah
> >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous owner
> >> has
> >> > > > > modified the battery pack already. A couple of mine needed a
> >> nibbler
> >> > > tool
> >> > > > > to remove enough of the aluminum cover that fits over the tops of
> >> the
> >> > > > > batteries. The original cover will short out to the battery tabs
> >> > > regardless
> >> > > > > of the battery configuration if this is not done.
> >> > > > >
> >> > > > > You can find larger capacity batteries that will give you slightly
> >> more
> >> > > > > battery life. I lost a couple sets of mail-order batteries after a
> >> few
> >> > > > > extended outages. I would recommend going with locally bought
> >> batteries
> >> > > > > instead of the cheaper mail order. My local Batteries Plus will
> >> > > typically
> >> > > > > have some warranty if I remember correctly. Moving forward I will
> >> only
> >> > > use
> >> > > > > 2 12v batteries and pre-charge them on a battery charger to
> >> equalize
> >> > > them
> >> > > > > before putting them in the 732A. I think the cheap batteries did
> >> not
> >> > > > > discharge equally, and would not recover when power was applied.
> >> > > > >
> >> > > > > Inspect the back plane for damaged traces and look at the
> >> capacitors. I
> >> > > had
> >> > > > > a few that looked questionable. So far, I have replaced all the
> >> big
> >> > > caps
> >> > > on
> >> > > > > the pre-regulator and regulator boards. My feeling is that once
> >> these
> >> > > go
> >> > > > > online, they should run as long as possible between repairs.
> >> > > > >
> >> > > > > The battery charger circuit may need adjusting. I tweaked mine and
> >> it
> >> > > > > seemed to work fine.
> >> > > > >
> >> > > > > Todd
> >> > > > >
> >> > > > >
> >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> >> > > randyevans2688@gmail.com>
> >> > > > > wrote:
> >> > > > >
> >> > > > > > I received my Fluke 732A today. Just powered it up but it needs
> >> new
> >> > > > > > batteries. Any suggestions for sources (I haven't opened up the
> >> unit
> >> > > > > yet -
> >> > > > > > I want to make sure it works before doing that). Also received
> >> the
> >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL ran
> >> data
> >> > > > > dumper
> >> > > > > > program to get the CAL data from my 3458A. Should be a busy
> >> weekend.
> >> > > > > >
> >> > > > > > Randy
> >> > > > > > _______________________________________________
> >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > > > > > To unsubscribe, go to
> >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > > > > > and follow the instructions there.
> >> > > > > >
> >> > > > > _______________________________________________
> >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > > > > To unsubscribe, go to
> >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > > > > and follow the instructions there.
> >> > > > >
> >> > > > _______________________________________________
> >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > > > To unsubscribe, go to
> >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > > > and follow the instructions there.
> >> > >
> >> > > _______________________________________________
> >> > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > > To unsubscribe, go to
> >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > > and follow the instructions there.
> >> > >
> >> > _______________________________________________
> >> > volt-nuts mailing list -- volt-nuts@febo.com
> >> > To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > and follow the instructions there.
> >>
> >> _______________________________________________
> >> volt-nuts mailing list -- volt-nuts@febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> and follow the instructions there.
> >>
> >
> >
> _______________________________________________
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> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
P
pa4tim@gmail.com
Wed, Aug 27, 2014 5:08 AM
Thanks, I did not new NIST has so much interesting information on their site.
I read the following on their site :
"multirange instruments with up to eight decimal digits of adjustability, are not considered by NIST to be standards "
Does that mean a HP3458 ? Fluke in the Netherlands used a HP-3458 and a 732 to calibrate the Fluke 5101 that I'm working on at this moment (it failed calibration due to some hardware faults)
Everybody thanks for the information. Turns out, a friend has a GR 1455AH for me, that is some kind a AC KV divider.
I will test if the output of my HP 3400 is usable to connect a DMM. I have one I restored a few years ago. Besides that someone mentioned to look at the LT-1088.
But that has to wait until I have some more time. I only repaired calibration, percission gear and RF stuff for my hobby, but, not planned, I started to do this on a commercial base too. See my (non commercial) site about my collection calibration and other gear and projects www.pa4tim.nl .
Today the 5101 goes back to the custommer but he brings 2 other instruments in need of some TLC and a precheck before they are shipped to Fluke for calibration. And yesterday an other company asked if I want/can repair a G&M safety tester (a sort of megger on steroids) that died during calibration.
Fred
Verzonden met Windows Mail
Van: acbern@gmx.de
Verzonden: ‎dinsdag‎ ‎26‎ ‎augustus‎ ‎2014 ‎18‎:‎56
Aan: volt-nuts
Dave,
the title is:
Thermal Voltage Converters and Comparator for Very Accurate AC Voltage Measurements
by E.S.Williams.
Adrian
Gesendet: Montag, 25. August 2014 um 19:32 Uhr
Von: "Dave M" dgminala@mediacombb.net
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] AC calibration
Adrian,
Do you have a link or title for the NIST paper that you mentioned?
Dave M
acbern@gmx.de wrote:
fred,
generally you raise a good point, I had the same issue of calibrating
an ac voltage to a high level of accuracy. you need this e.g. to
validate the self.cal of a 3458a or other precison stuff like the
8506a0.
what i would recommend to do if you want to keep costs down is:
in a nutshell, get a thermal converter in the lowest range you need
and a second one on range above. build a set of resistor range
extenders (rf type with appropriate connectors and housings) to
expand the range to where you need to be max. get one of the thermal
converter calibrated (the higher one usually, and you need to havr
good cal lab, should be <10ppm accuracy) and use it to calibrate the
rest. generally, up to 20khz, the accuracy is some 20 ppm anyway for
thermal converters! at higher frequencies, due to reflections and
stray capacitance/inductance influences, the accuracy decreases. the
resistor range extenders though, if build up correctly, only have a
few ppm impact (there is a paper from nist on that, but this is only
typical). you can calibrate all converters to the one you got
externally calibrated. do some research in the web, when you do the
calibration, you need to determine the so-called constant N. then do
an ac, dc+, ac, dc-, ac measurement between the the two and establish
the deviation, also establish the error propagation. the end result
will be a set of highly precise (low inaccuracies9 thermal converters
good enough to calibrate a 3458a an better devices. if you want to
spend the money, you could also buy a set of converters/range
resistors (with/without a 540), that typically is a few k altogether,
while a single device sometimes is available for below 100 bucks. you
need to have a stable 7.5 digit nanovoltmeter though for the
measurements of the tvcs (34420a or 2182 typically ) and precision
(stable) dc and ac sources. but in the end, all you need is a single
calibrated thermal converter.
adrian
Gesendet: Montag, 25. August 2014 um 18:38 Uhr
Von: "Dave M" dgminala@mediacombb.net
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] AC calibration
Well, you sort of answered your own question. The equipment is
called a Thermal Transfer Standard, but instead of thermistors, it
uses a thermocouple. Look at the manual for the Fluke 540B
(http://bama.edebris.com/manuals/fluke/540b/) and you'll see how
it's done. Basically, the AC source is input into the transfer
standard, and the standard's internal reference voltage is adjusted
for a null on the galvanometer. Leaving the reference voltage
setting alone, a DC voltage is input into the unit, and the DC
source is adjusted for a null on the galvanometer. At that point,
the AC voltage source is equal to that of the DC voltage source.
Ther are thermocouple-type thermal converters used for RF voltage
measurements with the transfer standard. They aren't cheap, and you
have to have a converter for each range of voltages that you need to
measure. The thermal converters used with this type of transfer
standard isn't great (50 MHz or so typical), but their accuracy far
surpasses that of the thermistor type sensors.
There are other brands and models of thermal transfer standards, but
I have a Fluke model 540 and a few thermal converters. That's why I
referred you to the manual for it.
Cheers,
Dave M
pa4tim@gmail.com wrote:
Is there a way to link an AC voltage to a DC source for compare. I
can check my calibrators (like a Fluke 332, 760 , 731 and a Philips)
against standardcells. But for AC I can not do that. I have two
AC+DC TRMS 7,5 digit meters but the last calibration was 2 years
ago.
My idea is in theory simple. It is based on the thermal converters
used in RF powermeters. Two resistors, two high resolution
temperature meters. AC on the first en DC on the second. If both are
the same temperature the AC voltage is the same as the DC voltage.
But I'm sure some people here have done this in the past. I would
like to use it for 50 to 100 kHz (or less) and something like for
1V, 10V and 100V (and use several resistors/heaters.)
Or mabey there is an other way to convert AC (for RF it can be done
with lightbubs but I never tryed that) I do not mind if it is slow
etc, I like this sort of experiments. You can learn a lot from it.
Fred, pa4tim
Thanks, I did not new NIST has so much interesting information on their site.
I read the following on their site :
"multirange instruments with up to eight decimal digits of adjustability, are not considered by NIST to be standards "
Does that mean a HP3458 ? Fluke in the Netherlands used a HP-3458 and a 732 to calibrate the Fluke 5101 that I'm working on at this moment (it failed calibration due to some hardware faults)
Everybody thanks for the information. Turns out, a friend has a GR 1455AH for me, that is some kind a AC KV divider.
I will test if the output of my HP 3400 is usable to connect a DMM. I have one I restored a few years ago. Besides that someone mentioned to look at the LT-1088.
But that has to wait until I have some more time. I only repaired calibration, percission gear and RF stuff for my hobby, but, not planned, I started to do this on a commercial base too. See my (non commercial) site about my collection calibration and other gear and projects www.pa4tim.nl .
Today the 5101 goes back to the custommer but he brings 2 other instruments in need of some TLC and a precheck before they are shipped to Fluke for calibration. And yesterday an other company asked if I want/can repair a G&M safety tester (a sort of megger on steroids) that died during calibration.
Fred
Verzonden met Windows Mail
Van: acbern@gmx.de
Verzonden: ‎dinsdag‎ ‎26‎ ‎augustus‎ ‎2014 ‎18‎:‎56
Aan: volt-nuts
Dave,
the title is:
Thermal Voltage Converters and Comparator for Very Accurate AC Voltage Measurements
by E.S.Williams.
Adrian
> Gesendet: Montag, 25. August 2014 um 19:32 Uhr
> Von: "Dave M" <dgminala@mediacombb.net>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] AC calibration
>
> Adrian,
> Do you have a link or title for the NIST paper that you mentioned?
>
> Dave M
>
>
> acbern@gmx.de wrote:
> > fred,
> > generally you raise a good point, I had the same issue of calibrating
> > an ac voltage to a high level of accuracy. you need this e.g. to
> > validate the self.cal of a 3458a or other precison stuff like the
> > 8506a0.
> >
> > what i would recommend to do if you want to keep costs down is:
> > in a nutshell, get a thermal converter in the lowest range you need
> > and a second one on range above. build a set of resistor range
> > extenders (rf type with appropriate connectors and housings) to
> > expand the range to where you need to be max. get one of the thermal
> > converter calibrated (the higher one usually, and you need to havr
> > good cal lab, should be <10ppm accuracy) and use it to calibrate the
> > rest. generally, up to 20khz, the accuracy is some 20 ppm anyway for
> > thermal converters! at higher frequencies, due to reflections and
> > stray capacitance/inductance influences, the accuracy decreases. the
> > resistor range extenders though, if build up correctly, only have a
> > few ppm impact (there is a paper from nist on that, but this is only
> > typical). you can calibrate all converters to the one you got
> > externally calibrated. do some research in the web, when you do the
> > calibration, you need to determine the so-called constant N. then do
> > an ac, dc+, ac, dc-, ac measurement between the the two and establish
> > the deviation, also establish the error propagation. the end result
> > will be a set of highly precise (low inaccuracies9 thermal converters
> > good enough to calibrate a 3458a an better devices. if you want to
> > spend the money, you could also buy a set of converters/range
> > resistors (with/without a 540), that typically is a few k altogether,
> > while a single device sometimes is available for below 100 bucks. you
> > need to have a stable 7.5 digit nanovoltmeter though for the
> > measurements of the tvcs (34420a or 2182 typically ) and precision
> > (stable) dc and ac sources. but in the end, all you need is a single
> > calibrated thermal converter.
> >
> > adrian
> >
> >
> >
> >> Gesendet: Montag, 25. August 2014 um 18:38 Uhr
> >> Von: "Dave M" <dgminala@mediacombb.net>
> >> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> Betreff: Re: [volt-nuts] AC calibration
> >>
> >> Well, you sort of answered your own question. The equipment is
> >> called a Thermal Transfer Standard, but instead of thermistors, it
> >> uses a thermocouple. Look at the manual for the Fluke 540B
> >> (http://bama.edebris.com/manuals/fluke/540b/) and you'll see how
> >> it's done. Basically, the AC source is input into the transfer
> >> standard, and the standard's internal reference voltage is adjusted
> >> for a null on the galvanometer. Leaving the reference voltage
> >> setting alone, a DC voltage is input into the unit, and the DC
> >> source is adjusted for a null on the galvanometer. At that point,
> >> the AC voltage source is equal to that of the DC voltage source.
> >>
> >> Ther are thermocouple-type thermal converters used for RF voltage
> >> measurements with the transfer standard. They aren't cheap, and you
> >> have to have a converter for each range of voltages that you need to
> >> measure. The thermal converters used with this type of transfer
> >> standard isn't great (50 MHz or so typical), but their accuracy far
> >> surpasses that of the thermistor type sensors.
> >>
> >> There are other brands and models of thermal transfer standards, but
> >> I have a Fluke model 540 and a few thermal converters. That's why I
> >> referred you to the manual for it.
> >>
> >> Cheers,
> >> Dave M
> >>
> >>
> >> pa4tim@gmail.com wrote:
> >>> Is there a way to link an AC voltage to a DC source for compare. I
> >>> can check my calibrators (like a Fluke 332, 760 , 731 and a Philips)
> >>> against standardcells. But for AC I can not do that. I have two
> >>> AC+DC TRMS 7,5 digit meters but the last calibration was 2 years
> >>> ago.
> >>>
> >>> My idea is in theory simple. It is based on the thermal converters
> >>> used in RF powermeters. Two resistors, two high resolution
> >>> temperature meters. AC on the first en DC on the second. If both are
> >>> the same temperature the AC voltage is the same as the DC voltage.
> >>> But I'm sure some people here have done this in the past. I would
> >>> like to use it for 50 to 100 kHz (or less) and something like for
> >>> 1V, 10V and 100V (and use several resistors/heaters.)
> >>>
> >>> Or mabey there is an other way to convert AC (for RF it can be done
> >>> with lightbubs but I never tryed that) I do not mind if it is slow
> >>> etc, I like this sort of experiments. You can learn a lot from it.
> >>>
> >>> Fred, pa4tim
> >>
> >>
> >> _______________________________________________
> >> volt-nuts mailing list -- volt-nuts@febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow
> >> the instructions there.
> > _______________________________________________
> > volt-nuts mailing list -- volt-nuts@febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
>
> When the people fear the government, there is tyranny. When the
> government fears the people, there is liberty -- Thomas Jefferson
>
>
> Dave M
>
> _______________________________________________
> volt-nuts mailing list -- volt-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
A
acbern@gmx.de
Wed, Aug 27, 2014 9:14 AM
what nist means is that a precision meter is not considered a standard. you always measure against a true standard (732a, esi sr104...). nist does not mean that as part of doing equipment calibration a 3458a cannot be used as aid. also keep in mind nist has a different approach than a cal lab, for obvious reasons. a cal lab would do a transfer measurement using a 3458a and a voltage/current source, sure.
there are precision ratio transformers available from various vendors, they can be used for low frequency precision calibrations, up to 20khz only (if anybodys knows one specified above 20khz I am interested to hear). so they will help you only partially in calibrating even a low precision 5101.
Gesendet: Mittwoch, 27. August 2014 um 07:08 Uhr
Von: pa4tim@gmail.com
An: volt-nuts volt-nuts@febo.com
Betreff: Re: [volt-nuts] AC calibration
Thanks, I did not new NIST has so much interesting information on their site.
I read the following on their site :
"multirange instruments with up to eight decimal digits of adjustability, are not considered by NIST to be standards "
Does that mean a HP3458 ? Fluke in the Netherlands used a HP-3458 and a 732 to calibrate the Fluke 5101 that I'm working on at this moment (it failed calibration due to some hardware faults)
Everybody thanks for the information. Turns out, a friend has a GR 1455AH for me, that is some kind a AC KV divider.
I will test if the output of my HP 3400 is usable to connect a DMM. I have one I restored a few years ago. Besides that someone mentioned to look at the LT-1088.
But that has to wait until I have some more time. I only repaired calibration, percission gear and RF stuff for my hobby, but, not planned, I started to do this on a commercial base too. See my (non commercial) site about my collection calibration and other gear and projects www.pa4tim.nl .
Today the 5101 goes back to the custommer but he brings 2 other instruments in need of some TLC and a precheck before they are shipped to Fluke for calibration. And yesterday an other company asked if I want/can repair a G&M safety tester (a sort of megger on steroids) that died during calibration.
Fred
what nist means is that a precision meter is not considered a standard. you always measure against a true standard (732a, esi sr104...). nist does not mean that as part of doing equipment calibration a 3458a cannot be used as aid. also keep in mind nist has a different approach than a cal lab, for obvious reasons. a cal lab would do a transfer measurement using a 3458a and a voltage/current source, sure.
there are precision ratio transformers available from various vendors, they can be used for low frequency precision calibrations, up to 20khz only (if anybodys knows one specified above 20khz I am interested to hear). so they will help you only partially in calibrating even a low precision 5101.
> Gesendet: Mittwoch, 27. August 2014 um 07:08 Uhr
> Von: pa4tim@gmail.com
> An: volt-nuts <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] AC calibration
>
> Thanks, I did not new NIST has so much interesting information on their site.
>
>
>
>
> I read the following on their site :
>
> "multirange instruments with up to eight decimal digits of adjustability, are not considered by NIST to be standards "
>
>
>
>
> Does that mean a HP3458 ? Fluke in the Netherlands used a HP-3458 and a 732 to calibrate the Fluke 5101 that I'm working on at this moment (it failed calibration due to some hardware faults)
>
>
>
>
> Everybody thanks for the information. Turns out, a friend has a GR 1455AH for me, that is some kind a AC KV divider.
>
> I will test if the output of my HP 3400 is usable to connect a DMM. I have one I restored a few years ago. Besides that someone mentioned to look at the LT-1088.
>
>
> But that has to wait until I have some more time. I only repaired calibration, percission gear and RF stuff for my hobby, but, not planned, I started to do this on a commercial base too. See my (non commercial) site about my collection calibration and other gear and projects www.pa4tim.nl .
>
> Today the 5101 goes back to the custommer but he brings 2 other instruments in need of some TLC and a precheck before they are shipped to Fluke for calibration. And yesterday an other company asked if I want/can repair a G&M safety tester (a sort of megger on steroids) that died during calibration.
>
>
> Fred
>
>
RE
Randy Evans
Wed, Aug 27, 2014 12:13 PM
I am doing multiple 100 measurements simply to characterize the stability
of the 3458A and 732A units I just bought. After about 10 measurement sets
over 2 days I am seeing a variance of about .5 uV for the 10V output, or
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am already
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal)
unless the amb. temperature is really very stable (half a degree already
adds about 0.25ppm at 10v)
thanks
Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete? In
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one particular
case, I am taking a 100 readings with NLPC set for 1000 so its a long
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans randyevans2688@gmail.com
wrote:
Bill,
I am trying to figure out the MATH function without much success. I
the sequence you said (I looked up the instructions to understand what
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and it
the 40 measurements and the MATH symbol shows on the display during the
measurements. After the SMPL symbol no longer blinks I hit MATH 2 and
get a MATH ERR symbol on the display. I tried it a couple of times
same result so I am doing something wrong. Is there a better source
explaining how to do front panel masurements than the User Guide, which
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't have an
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona
banana plugs and Belden #9272 wire. Why 9272, because it was handy
time. It is tin plated copper, shielded twisted pair 20 ga. I have
to do custom cables with 16 ga. bare copper wire that I will twist and
then
put a braided shield over it. I simply cannot find what I want so I
build my own cable. I have done something like this before and it
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
used
in the past to verify my homemade "low thermal" leads as described
Frankly I cannot see any difference between using the 1756 cables and
homemade cables once I give them a few minutes for the thermals to go
away.
As far as I can tell and measure the differences, if any, are below
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
adjustable you may be seeing a misadjusted 1 volt from the 732A. As
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with the
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this does
set
the MATH to "Statistics" (store high reading/low reading/ and mean of
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press "ENTER"
then
trigger the sequence of 40 readings when I push the "ENTER" button.
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and PLC to
100.
Once those 40 readings are finished then you can access the various
statistic registers, using the menu, by entering "MATH" and then a 2
low, a 4 for mean, and 13 for high. Of course you could do all of
through the IEEE also. The 3458A has a very rich set of measurement
commands. I am still learning all of them. It depends upon what I am
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived from
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and then
observe
the variations that way without the 732A involved. When I do this I
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the low
side
of the measurment terminals, GUARD connected doesn't seem to affect
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt output
got
a variation of 0.159 uVolts using the same 40 reading method above. I
would
use this to determine where your problem might exist. Just having the
meter
input shorted will point you in the right direction. Meter, cables or
732A.
Sorry for the long dissertation. Friends get mad at me for being
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a small
rather than letting my hand touch the plugs, it is much more stable.
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value of
readings are very different between the two - the 3458 reads about
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some better
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they will
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic LC-R064R5C
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very common
as
it is used in a lot of "EXIT" signs so they are lighted when the
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack. You
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with the
New batteries will last around 12 to 14 hours before the "CAL"
out when AC power is not applied. So shipping to Cal Lab can be a
if it is a distance away, or you have to use a shipper like UPS or
and
you ship the night before and then use their "Morning delivery"
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it up to
power" plug to last longer. I have seen it done. The issue is
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have the
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been lost
Reference Amp or other associated circuits. When the raw supply
voltage drops below about 21 volts the "CAL" light will go out.
voltage the heater circuits will not work correctly and the 18.6
regulated supply will not regulate. The requirement is that the
Amp be kept "alive" at all times to maintain the output voltage
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when power
and then power is restored the result will be a different 10 volts
before the power failure. My experience is that after all of the
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come back to
exactly the same 10 volts as when they lost power, usually with
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the 1
output? What is the PLC set to? I always use 100 PLC to measure
you don't have "low thermal" connection leads you can experience
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between the
on the 732A and the banana plugs of the leads. I have found that
plugging in the lead will generate a thermal difference because of
difference of temps and some heating due to the physical act of
inserting the plug because of friction between the jack and plug
at any rate). You have to allow at least a minute or more before
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A and I
total difference of 0.159 uV over 40 measurements using 100 PLC
volt range of the 3458A. Using the MATH function and all of the
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to 3 mA
VDC) when charged and at their float voltage, so I am pretty
in good condition. I will look at getting those in the units
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only concerned
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with 4 x
batteries or 2 x 12v 7Ah batteries. Hopefully the previous
modified the battery pack already. A couple of mine needed a
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the battery
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order batteries
extended outages. I would recommend going with locally bought
instead of the cheaper mail order. My local Batteries Plus
have some warranty if I remember correctly. Moving forward I
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap batteries
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all
the pre-regulator and regulator boards. My feeling is that
online, they should run as long as possible between repairs.
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but it
batteries. Any suggestions for sources (I haven't opened
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
program to get the CAL data from my 3458A. Should be a busy
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
I am doing multiple 100 measurements simply to characterize the stability
of the 3458A and 732A units I just bought. After about 10 measurement sets
over 2 days I am seeing a variance of about .5 uV for the 10V output, or
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
> hi randy,
>
> just for curiosity, why doing 100 measurements at nplc 1000. is this to
> sample a changing value?
> when i am doing 10 measurements from a stable signal at nplc 100 (only
> there many subsequent measuremnts with statistics make sense) I am already
> getting a stanard deviation below 0.1ppm.
> in a 30 minute test cycle, i would also be concerned about drifts (acal)
> unless the amb. temperature is really very stable (half a degree already
> adds about 0.25ppm at 10v)
>
> thanks
>
>
>
>
> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> > Von: "Randy Evans" <randyevans2688@gmail.com>
> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > Betreff: Re: [volt-nuts] 732A and Prologix received
> >
> > Is there any way to tell when the function key routine is complete? In
> the
> > case of taking multiple readings using the DEFKEY and MATH function, I
> > don't see any indication when the routine is complete. In one particular
> > case, I am taking a 100 readings with NLPC set for 1000 so its a long
> while
> > before it's complete, but i have to guess when it's done.
> >
> > Thanks,
> >
> > Randy
> >
> >
> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <randyevans2688@gmail.com>
> > wrote:
> >
> > > Bill,
> > >
> > > I am trying to figure out the MATH function without much success. I
> input
> > > the sequence you said (I looked up the instructions to understand what
> you
> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
> 4;TRIG; and
> > > it shows up on the display when I input BLUE F1. I hit ENTER and it
> takes
> > > the 40 measurements and the MATH symbol shows on the display during the
> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2 and
> I
> > > get a MATH ERR symbol on the display. I tried it a couple of times
> and the
> > > same result so I am doing something wrong. Is there a better source
> for
> > > explaining how to do front panel masurements than the User Guide, which
> > > seems oriented at programming automatic rather than manual
> measurements.
> > >
> > > Randy
> > >
> > >
> > >
> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net> wrote:
> > >
> > >> Randy:
> > >>
> > >> The MATH function is accessible from the keypad. I don't have an
> IEEE
> > >> interface right now that works. You can also program the numeric
> keypad
> > >> keys to have preprogrammed functions. DEFKEY
> > >>
> > >> I have made my own "low thermal" measurement leads from Pomona
> #4892
> > >> banana plugs and Belden #9272 wire. Why 9272, because it was handy
> at the
> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I have
> plans
> > >> to do custom cables with 16 ga. bare copper wire that I will twist and
> > >> then
> > >> put a braided shield over it. I simply cannot find what I want so I
> will
> > >> build my own cable. I have done something like this before and it
> worked
> > >> fine. When I get a "round toit".
> > >>
> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
> have
> > >> used
> > >> in the past to verify my homemade "low thermal" leads as described
> above.
> > >> Frankly I cannot see any difference between using the 1756 cables and
> my
> > >> homemade cables once I give them a few minutes for the thermals to go
> > >> away.
> > >> As far as I can tell and measure the differences, if any, are below
> 0.1
> > >> ppm
> > >> at 10 volts.
> > >>
> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
> are all
> > >> adjustable you may be seeing a misadjusted 1 volt from the 732A. As
> far
> > >> as
> > >> the instability of the readings it is hard to determine which is
> causing
> > >> the
> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with the
> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this does
> is
> > >> set
> > >> the MATH to "Statistics" (store high reading/low reading/ and mean of
> the
> > >> readings) in the registers, the number of readings to "40", the
> trigger to
> > >> "hold" (which keeps the meter from triggering until I press "ENTER"
> and
> > >> then
> > >> trigger the sequence of 40 readings when I push the "ENTER" button.
> You
> > >> can
> > >> do all of this manually from the keypads but since I use this
> sequence a
> > >> lot
> > >> I have preprogrammed it. This is after I set digits to "8" and PLC to
> > >> 100.
> > >> Once those 40 readings are finished then you can access the various
> MATH
> > >> statistic registers, using the menu, by entering "MATH" and then a 2
> for
> > >> low, a 4 for mean, and 13 for high. Of course you could do all of
> this
> > >> through the IEEE also. The 3458A has a very rich set of measurement
> > >> commands. I am still learning all of them. It depends upon what I am
> > >> trying to accomplish.
> > >>
> > >> Since the 1.018 and 1.0 volt outputs are passive and derived from
> > >> resistive dividers from the 10 volt, I don't see how they could
> contribute
> > >> to the varying readings you are measuring. I think I would put a
> short on
> > >> the input of the 3458A and manually set the range to 1 volt and then
> > >> observe
> > >> the variations that way without the 732A involved. When I do this I
> see a
> > >> variation from low reading to high reading of 0.125 uVolts and then
> > >> another
> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to the low
> > >> side
> > >> of the measurment terminals, GUARD connected doesn't seem to affect
> the
> > >> readings. So that is the base noise of the 3458A without the 732A,
> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt output
> I
> > >> got
> > >> a variation of 0.159 uVolts using the same 40 reading method above. I
> > >> would
> > >> use this to determine where your problem might exist. Just having the
> > >> meter
> > >> input shorted will point you in the right direction. Meter, cables or
> > >> 732A.
> > >>
> > >> Sorry for the long dissertation. Friends get mad at me for being
> so
> > >> detailed sometimes.
> > >>
> > >> Bill
> > >>
> > >> ----- Original Message -----
> > >> From: "Randy Evans" <randyevans2688@gmail.com>
> > >> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > >> Sent: Sunday, August 24, 2014 7:22 AM
> > >> Subject: Re: [volt-nuts] 732A and Prologix received
> > >>
> > >>
> > >> > Bill,
> > >> >
> > >> > I have convinced myself that the problem I an seeing is due to
> thermals.
> > >> > If I move the cables (with gold-plated banana plugs) using a small
> > >> towel
> > >> > rather than letting my hand touch the plugs, it is much more stable.
> > >> If I
> > >> > then hold the banana plug with my hand after the reading has
> stabilized,
> > >> > the reading drifts rapidly upward. I am trying to check the
> stability
> > >> of
> > >> > the reading but I haven't figured out the MATH function yet. I
> assume
> > >> this
> > >> > is a programmed function using GPIB only?
> > >> >
> > >> > The stability I am seeing by manually recording readings (using
> NLPC of
> > >> 100
> > >> > and 1000) is much greater than what you are measuring on your
> system.
> > >> Not
> > >> > sure how to ascertain if it's the 3458A or the 732. The value of
> the
> > >> > readings are very different between the two - the 3458 reads about
> 50 uV
> > >> > high on the 10 V output and about 12 uV low on the 1V output.
> Rather
> > >> large
> > >> > differences (this is after an ACAL). I need to find some better
> cables
> > >> to
> > >> > make sure the errors are not due to thermals again.
> > >> >
> > >> > Randy
> > >> >
> > >> >
> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net>
> wrote:
> > >> >
> > >> > > Randy:
> > >> > >
> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they will
> fit
> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic LC-R064R5C
> and
> > >> > > others
> > >> > > that are in this size and package. Order from one of the usual
> > >> electronics
> > >> > > distributors like Allied, Mouser, Digikey. This is a very common
> > >> battery
> > >> > > as
> > >> > > it is used in a lot of "EXIT" signs so they are lighted when the
> power
> > >> goes
> > >> > > out. I don't see how the 12V 7AH will fit as they are too
> large. I
> > >> guess
> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
> volt
> > >> 4
> > >> AH
> > >> > > but the terminals are in the wrong place so you will have to
> "nibble"
> > >> out
> > >> > > the aluminum plate that holds them in the 732A battery pack. You
> have
> > >> to
> > >> > > be
> > >> > > careful if you use the 12v 5AH as you will have 4 extra battery
> > >> connection
> > >> > > leads to deal with and connect correctly. I would stick with the
> 6V
> > >> 4AH.
> > >> > > New batteries will last around 12 to 14 hours before the "CAL"
> light
> > >> goes
> > >> > > out when AC power is not applied. So shipping to Cal Lab can be a
> > >> problem
> > >> > > if it is a distance away, or you have to use a shipper like UPS or
> > >> FEDEX
> > >> > > and
> > >> > > you ship the night before and then use their "Morning delivery"
> and
> > >> the
> > >> Cal
> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> course
> > >> you
> > >> > > could always strap another battery on the 732A and hook it up to
> the
> > >> "ext
> > >> > > power" plug to last longer. I have seen it done. The issue is
> to get
> > >> the
> > >> > > Cal Lab to charge the extra battery before they ship the 732A
> back to
> > >> you.
> > >> > >
> > >> > > When you remove and work on the battery pack always have the
> AC
> > >> power
> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> regulated
> > >> supply
> > >> > > is working.
> > >> > >
> > >> > > The "CAL" light is to indicate that power has not been lost
> to the
> > >> > > Reference Amp or other associated circuits. When the raw supply
> > >> (battery)
> > >> > > voltage drops below about 21 volts the "CAL" light will go out.
> Below
> > >> that
> > >> > > voltage the heater circuits will not work correctly and the 18.6
> volt
> > >> > > regulated supply will not regulate. The requirement is that the
> > >> Reference
> > >> > > Amp be kept "alive" at all times to maintain the output voltage
> that
> > >> was
> > >> > > measured at the time of the most recent Calibration or
> Certification.
> > >> When
> > >> > > the semiconductor junctions are unbiased and cool off when power
> is
> > >> lost,
> > >> > > and then power is restored the result will be a different 10 volts
> > >> than
> > >> > > before the power failure. My experience is that after all of the
> > >> years
> > >> > > that
> > >> > > these units have been powered up, this won't happen and when
> power is
> > >> lost
> > >> > > and then restored, even months later, the 732A will come back to
> > >> almost
> > >> > > exactly the same 10 volts as when they lost power, usually with
> in 0.2
> > >> PPM
> > >> > > after 24 hours of "warm up".
> > >> > >
> > >> > > What type of hookup leads are you using when measuring the 1
> volt
> > >> > > output? What is the PLC set to? I always use 100 PLC to measure
> > >> this.
> > >> If
> > >> > > you don't have "low thermal" connection leads you can experience
> uV
> > >> changes
> > >> > > for a minute or more after plugging in the leads due to the
> "thermals"
> > >> > > generated because of the difference in temperature between the
> banana
> > >> jacks
> > >> > > on the 732A and the banana plugs of the leads. I have found that
> even
> > >> just
> > >> > > plugging in the lead will generate a thermal difference because of
> > >> > > difference of temps and some heating due to the physical act of
> just
> > >> > > inserting the plug because of friction between the jack and plug
> (my
> > >> theory
> > >> > > at any rate). You have to allow at least a minute or more before
> > >> being
> > >> > > able
> > >> > > to make a measurement after plugging in the leads. I just
> measured
> > >> the
> > >> > > variation of the 1 volt output of my 732A and using my 3458A and I
> > >> got a
> > >> > > total difference of 0.159 uV over 40 measurements using 100 PLC
> on
> > >> the
> > >> 1
> > >> > > volt range of the 3458A. Using the MATH function and all of the
> data
> > >> you
> > >> > > can collect. That was after waiting for several minutes after
> > >> plugging
> > >> in
> > >> > > the leads.
> > >> > >
> > >> > > I hope all of this helps.
> > >> > >
> > >> > > Bill
> > >> > >
> > >> > >
> > >> > >
> > >> > > ----- Original Message -----
> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> > >> > > To: "Discussion of precise voltage measurement" <
> volt-nuts@febo.com>
> > >> > > Sent: Friday, August 22, 2014 9:03 PM
> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> > >> > >
> > >> > >
> > >> > > > Todd,
> > >> > > >
> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> batteries
> > >> that
> > >> I
> > >> > > > keep topped off and they have very low current draw (~2 to 3 mA
> at
> > >> 13.5
> > >> > > > VDC) when charged and at their float voltage, so I am pretty
> sure
> > >> they
> > >> > > are
> > >> > > > in good condition. I will look at getting those in the units
> after
> > >> I
> > >> > > > ascertain the condition of the 732.
> > >> > > >
> > >> > > > So now I have a what appears to be a functioning 3458A and a
> 732A
> > >> but
> > >> > > they
> > >> > > > slightly disagree. I am like the man with two watches that
> disagree
> > >> on
> > >> > > the
> > >> > > > time - which is correct? For the moment, i am only concerned
> with
> > >> > > > stability. The need for absolute accuracy will come later.
> > >> > > >
> > >> > > > Randy
> > >> > > >
> > >> > > >
> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
> tmicallef@gmail.com
> > >> >
> > >> > > wrote:
> > >> > > >
> > >> > > > > Randy,
> > >> > > > >
> > >> > > > > You have two possible choices. It can be configured with 4 x
> 6v
> > >> 4Ah
> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous
> owner
> > >> has
> > >> > > > > modified the battery pack already. A couple of mine needed a
> > >> nibbler
> > >> > > tool
> > >> > > > > to remove enough of the aluminum cover that fits over the
> tops of
> > >> the
> > >> > > > > batteries. The original cover will short out to the battery
> tabs
> > >> > > regardless
> > >> > > > > of the battery configuration if this is not done.
> > >> > > > >
> > >> > > > > You can find larger capacity batteries that will give you
> slightly
> > >> more
> > >> > > > > battery life. I lost a couple sets of mail-order batteries
> after a
> > >> few
> > >> > > > > extended outages. I would recommend going with locally bought
> > >> batteries
> > >> > > > > instead of the cheaper mail order. My local Batteries Plus
> will
> > >> > > typically
> > >> > > > > have some warranty if I remember correctly. Moving forward I
> will
> > >> only
> > >> > > use
> > >> > > > > 2 12v batteries and pre-charge them on a battery charger to
> > >> equalize
> > >> > > them
> > >> > > > > before putting them in the 732A. I think the cheap batteries
> did
> > >> not
> > >> > > > > discharge equally, and would not recover when power was
> applied.
> > >> > > > >
> > >> > > > > Inspect the back plane for damaged traces and look at the
> > >> capacitors. I
> > >> > > had
> > >> > > > > a few that looked questionable. So far, I have replaced all
> the
> > >> big
> > >> > > caps
> > >> > > on
> > >> > > > > the pre-regulator and regulator boards. My feeling is that
> once
> > >> these
> > >> > > go
> > >> > > > > online, they should run as long as possible between repairs.
> > >> > > > >
> > >> > > > > The battery charger circuit may need adjusting. I tweaked
> mine and
> > >> it
> > >> > > > > seemed to work fine.
> > >> > > > >
> > >> > > > > Todd
> > >> > > > >
> > >> > > > >
> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> > >> > > randyevans2688@gmail.com>
> > >> > > > > wrote:
> > >> > > > >
> > >> > > > > > I received my Fluke 732A today. Just powered it up but it
> needs
> > >> new
> > >> > > > > > batteries. Any suggestions for sources (I haven't opened
> up the
> > >> unit
> > >> > > > > yet -
> > >> > > > > > I want to make sure it works before doing that). Also
> received
> > >> the
> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
> ran
> > >> data
> > >> > > > > dumper
> > >> > > > > > program to get the CAL data from my 3458A. Should be a busy
> > >> weekend.
> > >> > > > > >
> > >> > > > > > Randy
> > >> > > > > > _______________________________________________
> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > > > > > To unsubscribe, go to
> > >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > > > > > and follow the instructions there.
> > >> > > > > >
> > >> > > > > _______________________________________________
> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > > > > To unsubscribe, go to
> > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > > > > and follow the instructions there.
> > >> > > > >
> > >> > > > _______________________________________________
> > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > > > To unsubscribe, go to
> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > > > and follow the instructions there.
> > >> > >
> > >> > > _______________________________________________
> > >> > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > > To unsubscribe, go to
> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > > and follow the instructions there.
> > >> > >
> > >> > _______________________________________________
> > >> > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > To unsubscribe, go to
> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > and follow the instructions there.
> > >>
> > >> _______________________________________________
> > >> volt-nuts mailing list -- volt-nuts@febo.com
> > >> To unsubscribe, go to
> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> and follow the instructions there.
> > >>
> > >
> > >
> > _______________________________________________
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RE
Randy Evans
Wed, Aug 27, 2014 12:36 PM
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans randyevans2688@gmail.com
wrote:
I am doing multiple 100 measurements simply to characterize the stability
of the 3458A and 732A units I just bought. After about 10 measurement sets
over 2 days I am seeing a variance of about .5 uV for the 10V output, or
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am already
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal)
unless the amb. temperature is really very stable (half a degree already
adds about 0.25ppm at 10v)
thanks
Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete? In
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a long
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans randyevans2688@gmail.com
wrote:
Bill,
I am trying to figure out the MATH function without much success. I
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and it
the 40 measurements and the MATH symbol shows on the display during
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of times
same result so I am doing something wrong. Is there a better source
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't have
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona
banana plugs and Belden #9272 wire. Why 9272, because it was handy
time. It is tin plated copper, shielded twisted pair 20 ga. I have
to do custom cables with 16 ga. bare copper wire that I will twist
then
put a braided shield over it. I simply cannot find what I want so I
build my own cable. I have done something like this before and it
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
used
in the past to verify my homemade "low thermal" leads as described
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals to go
away.
As far as I can tell and measure the differences, if any, are below
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
adjustable you may be seeing a misadjusted 1 volt from the 732A. As
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with the
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and mean
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press "ENTER"
then
trigger the sequence of 40 readings when I push the "ENTER" button.
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and PLC
Once those 40 readings are finished then you can access the various
statistic registers, using the menu, by entering "MATH" and then a 2
low, a 4 for mean, and 13 for high. Of course you could do all of
through the IEEE also. The 3458A has a very rich set of measurement
commands. I am still learning all of them. It depends upon what I
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived from
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and then
observe
the variations that way without the 732A involved. When I do this I
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the
side
of the measurment terminals, GUARD connected doesn't seem to affect
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method above.
would
use this to determine where your problem might exist. Just having
meter
input shorted will point you in the right direction. Meter, cables
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a small
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value of
readings are very different between the two - the 3458 reads about
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some better
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very common
as
it is used in a lot of "EXIT" signs so they are lighted when the
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the "CAL"
out when AC power is not applied. So shipping to Cal Lab can be
if it is a distance away, or you have to use a shipper like UPS
and
you ship the night before and then use their "Morning delivery"
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it up to
power" plug to last longer. I have seen it done. The issue is
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have the
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been lost
Reference Amp or other associated circuits. When the raw supply
voltage drops below about 21 volts the "CAL" light will go out.
voltage the heater circuits will not work correctly and the 18.6
regulated supply will not regulate. The requirement is that the
Amp be kept "alive" at all times to maintain the output voltage
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when power
and then power is restored the result will be a different 10
before the power failure. My experience is that after all of the
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come back to
exactly the same 10 volts as when they lost power, usually with
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the 1
output? What is the PLC set to? I always use 100 PLC to measure
you don't have "low thermal" connection leads you can experience
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between the
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference because
difference of temps and some heating due to the physical act of
inserting the plug because of friction between the jack and plug
at any rate). You have to allow at least a minute or more before
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A and
total difference of 0.159 uV over 40 measurements using 100 PLC
volt range of the 3458A. Using the MATH function and all of the
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to 3
VDC) when charged and at their float voltage, so I am pretty
in good condition. I will look at getting those in the units
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only concerned
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with 4 x
batteries or 2 x 12v 7Ah batteries. Hopefully the previous
modified the battery pack already. A couple of mine needed a
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the battery
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order batteries
extended outages. I would recommend going with locally bought
instead of the cheaper mail order. My local Batteries Plus
have some warranty if I remember correctly. Moving forward I
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap batteries
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all
the pre-regulator and regulator boards. My feeling is that
online, they should run as long as possible between repairs.
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but it
batteries. Any suggestions for sources (I haven't opened
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans <randyevans2688@gmail.com>
wrote:
> I am doing multiple 100 measurements simply to characterize the stability
> of the 3458A and 732A units I just bought. After about 10 measurement sets
> over 2 days I am seeing a variance of about .5 uV for the 10V output, or
> 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
> that sound reasonable/
>
> Randy
>
>
> On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
>
>> hi randy,
>>
>> just for curiosity, why doing 100 measurements at nplc 1000. is this to
>> sample a changing value?
>> when i am doing 10 measurements from a stable signal at nplc 100 (only
>> there many subsequent measuremnts with statistics make sense) I am already
>> getting a stanard deviation below 0.1ppm.
>> in a 30 minute test cycle, i would also be concerned about drifts (acal)
>> unless the amb. temperature is really very stable (half a degree already
>> adds about 0.25ppm at 10v)
>>
>> thanks
>>
>>
>>
>>
>> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
>> > Von: "Randy Evans" <randyevans2688@gmail.com>
>> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
>> > Betreff: Re: [volt-nuts] 732A and Prologix received
>> >
>> > Is there any way to tell when the function key routine is complete? In
>> the
>> > case of taking multiple readings using the DEFKEY and MATH function, I
>> > don't see any indication when the routine is complete. In one
>> particular
>> > case, I am taking a 100 readings with NLPC set for 1000 so its a long
>> while
>> > before it's complete, but i have to guess when it's done.
>> >
>> > Thanks,
>> >
>> > Randy
>> >
>> >
>> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <randyevans2688@gmail.com>
>> > wrote:
>> >
>> > > Bill,
>> > >
>> > > I am trying to figure out the MATH function without much success. I
>> input
>> > > the sequence you said (I looked up the instructions to understand
>> what you
>> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
>> 4;TRIG; and
>> > > it shows up on the display when I input BLUE F1. I hit ENTER and it
>> takes
>> > > the 40 measurements and the MATH symbol shows on the display during
>> the
>> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
>> and I
>> > > get a MATH ERR symbol on the display. I tried it a couple of times
>> and the
>> > > same result so I am doing something wrong. Is there a better source
>> for
>> > > explaining how to do front panel masurements than the User Guide,
>> which
>> > > seems oriented at programming automatic rather than manual
>> measurements.
>> > >
>> > > Randy
>> > >
>> > >
>> > >
>> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
>> wrote:
>> > >
>> > >> Randy:
>> > >>
>> > >> The MATH function is accessible from the keypad. I don't have
>> an IEEE
>> > >> interface right now that works. You can also program the numeric
>> keypad
>> > >> keys to have preprogrammed functions. DEFKEY
>> > >>
>> > >> I have made my own "low thermal" measurement leads from Pomona
>> #4892
>> > >> banana plugs and Belden #9272 wire. Why 9272, because it was handy
>> at the
>> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I have
>> plans
>> > >> to do custom cables with 16 ga. bare copper wire that I will twist
>> and
>> > >> then
>> > >> put a braided shield over it. I simply cannot find what I want so I
>> will
>> > >> build my own cable. I have done something like this before and it
>> worked
>> > >> fine. When I get a "round toit".
>> > >>
>> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
>> have
>> > >> used
>> > >> in the past to verify my homemade "low thermal" leads as described
>> above.
>> > >> Frankly I cannot see any difference between using the 1756 cables
>> and my
>> > >> homemade cables once I give them a few minutes for the thermals to go
>> > >> away.
>> > >> As far as I can tell and measure the differences, if any, are below
>> 0.1
>> > >> ppm
>> > >> at 10 volts.
>> > >>
>> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
>> are all
>> > >> adjustable you may be seeing a misadjusted 1 volt from the 732A. As
>> far
>> > >> as
>> > >> the instability of the readings it is hard to determine which is
>> causing
>> > >> the
>> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with the
>> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
>> does is
>> > >> set
>> > >> the MATH to "Statistics" (store high reading/low reading/ and mean
>> of the
>> > >> readings) in the registers, the number of readings to "40", the
>> trigger to
>> > >> "hold" (which keeps the meter from triggering until I press "ENTER"
>> and
>> > >> then
>> > >> trigger the sequence of 40 readings when I push the "ENTER" button.
>> You
>> > >> can
>> > >> do all of this manually from the keypads but since I use this
>> sequence a
>> > >> lot
>> > >> I have preprogrammed it. This is after I set digits to "8" and PLC
>> to
>> > >> 100.
>> > >> Once those 40 readings are finished then you can access the various
>> MATH
>> > >> statistic registers, using the menu, by entering "MATH" and then a 2
>> for
>> > >> low, a 4 for mean, and 13 for high. Of course you could do all of
>> this
>> > >> through the IEEE also. The 3458A has a very rich set of measurement
>> > >> commands. I am still learning all of them. It depends upon what I
>> am
>> > >> trying to accomplish.
>> > >>
>> > >> Since the 1.018 and 1.0 volt outputs are passive and derived from
>> > >> resistive dividers from the 10 volt, I don't see how they could
>> contribute
>> > >> to the varying readings you are measuring. I think I would put a
>> short on
>> > >> the input of the 3458A and manually set the range to 1 volt and then
>> > >> observe
>> > >> the variations that way without the 732A involved. When I do this I
>> see a
>> > >> variation from low reading to high reading of 0.125 uVolts and then
>> > >> another
>> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to the
>> low
>> > >> side
>> > >> of the measurment terminals, GUARD connected doesn't seem to affect
>> the
>> > >> readings. So that is the base noise of the 3458A without the 732A,
>> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
>> output I
>> > >> got
>> > >> a variation of 0.159 uVolts using the same 40 reading method above.
>> I
>> > >> would
>> > >> use this to determine where your problem might exist. Just having
>> the
>> > >> meter
>> > >> input shorted will point you in the right direction. Meter, cables
>> or
>> > >> 732A.
>> > >>
>> > >> Sorry for the long dissertation. Friends get mad at me for
>> being so
>> > >> detailed sometimes.
>> > >>
>> > >> Bill
>> > >>
>> > >> ----- Original Message -----
>> > >> From: "Randy Evans" <randyevans2688@gmail.com>
>> > >> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
>> > >> Sent: Sunday, August 24, 2014 7:22 AM
>> > >> Subject: Re: [volt-nuts] 732A and Prologix received
>> > >>
>> > >>
>> > >> > Bill,
>> > >> >
>> > >> > I have convinced myself that the problem I an seeing is due to
>> thermals.
>> > >> > If I move the cables (with gold-plated banana plugs) using a small
>> > >> towel
>> > >> > rather than letting my hand touch the plugs, it is much more
>> stable.
>> > >> If I
>> > >> > then hold the banana plug with my hand after the reading has
>> stabilized,
>> > >> > the reading drifts rapidly upward. I am trying to check the
>> stability
>> > >> of
>> > >> > the reading but I haven't figured out the MATH function yet. I
>> assume
>> > >> this
>> > >> > is a programmed function using GPIB only?
>> > >> >
>> > >> > The stability I am seeing by manually recording readings (using
>> NLPC of
>> > >> 100
>> > >> > and 1000) is much greater than what you are measuring on your
>> system.
>> > >> Not
>> > >> > sure how to ascertain if it's the 3458A or the 732. The value of
>> the
>> > >> > readings are very different between the two - the 3458 reads about
>> 50 uV
>> > >> > high on the 10 V output and about 12 uV low on the 1V output.
>> Rather
>> > >> large
>> > >> > differences (this is after an ACAL). I need to find some better
>> cables
>> > >> to
>> > >> > make sure the errors are not due to thermals again.
>> > >> >
>> > >> > Randy
>> > >> >
>> > >> >
>> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net>
>> wrote:
>> > >> >
>> > >> > > Randy:
>> > >> > >
>> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
>> will fit
>> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
>> LC-R064R5C and
>> > >> > > others
>> > >> > > that are in this size and package. Order from one of the usual
>> > >> electronics
>> > >> > > distributors like Allied, Mouser, Digikey. This is a very common
>> > >> battery
>> > >> > > as
>> > >> > > it is used in a lot of "EXIT" signs so they are lighted when the
>> power
>> > >> goes
>> > >> > > out. I don't see how the 12V 7AH will fit as they are too
>> large. I
>> > >> guess
>> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
>> volt
>> > >> 4
>> > >> AH
>> > >> > > but the terminals are in the wrong place so you will have to
>> "nibble"
>> > >> out
>> > >> > > the aluminum plate that holds them in the 732A battery pack.
>> You have
>> > >> to
>> > >> > > be
>> > >> > > careful if you use the 12v 5AH as you will have 4 extra battery
>> > >> connection
>> > >> > > leads to deal with and connect correctly. I would stick with
>> the 6V
>> > >> 4AH.
>> > >> > > New batteries will last around 12 to 14 hours before the "CAL"
>> light
>> > >> goes
>> > >> > > out when AC power is not applied. So shipping to Cal Lab can be
>> a
>> > >> problem
>> > >> > > if it is a distance away, or you have to use a shipper like UPS
>> or
>> > >> FEDEX
>> > >> > > and
>> > >> > > you ship the night before and then use their "Morning delivery"
>> and
>> > >> the
>> > >> Cal
>> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
>> course
>> > >> you
>> > >> > > could always strap another battery on the 732A and hook it up to
>> the
>> > >> "ext
>> > >> > > power" plug to last longer. I have seen it done. The issue is
>> to get
>> > >> the
>> > >> > > Cal Lab to charge the extra battery before they ship the 732A
>> back to
>> > >> you.
>> > >> > >
>> > >> > > When you remove and work on the battery pack always have the
>> AC
>> > >> power
>> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
>> regulated
>> > >> supply
>> > >> > > is working.
>> > >> > >
>> > >> > > The "CAL" light is to indicate that power has not been lost
>> to the
>> > >> > > Reference Amp or other associated circuits. When the raw supply
>> > >> (battery)
>> > >> > > voltage drops below about 21 volts the "CAL" light will go out.
>> Below
>> > >> that
>> > >> > > voltage the heater circuits will not work correctly and the 18.6
>> volt
>> > >> > > regulated supply will not regulate. The requirement is that the
>> > >> Reference
>> > >> > > Amp be kept "alive" at all times to maintain the output voltage
>> that
>> > >> was
>> > >> > > measured at the time of the most recent Calibration or
>> Certification.
>> > >> When
>> > >> > > the semiconductor junctions are unbiased and cool off when power
>> is
>> > >> lost,
>> > >> > > and then power is restored the result will be a different 10
>> volts
>> > >> than
>> > >> > > before the power failure. My experience is that after all of the
>> > >> years
>> > >> > > that
>> > >> > > these units have been powered up, this won't happen and when
>> power is
>> > >> lost
>> > >> > > and then restored, even months later, the 732A will come back to
>> > >> almost
>> > >> > > exactly the same 10 volts as when they lost power, usually with
>> in 0.2
>> > >> PPM
>> > >> > > after 24 hours of "warm up".
>> > >> > >
>> > >> > > What type of hookup leads are you using when measuring the 1
>> volt
>> > >> > > output? What is the PLC set to? I always use 100 PLC to measure
>> > >> this.
>> > >> If
>> > >> > > you don't have "low thermal" connection leads you can experience
>> uV
>> > >> changes
>> > >> > > for a minute or more after plugging in the leads due to the
>> "thermals"
>> > >> > > generated because of the difference in temperature between the
>> banana
>> > >> jacks
>> > >> > > on the 732A and the banana plugs of the leads. I have found
>> that even
>> > >> just
>> > >> > > plugging in the lead will generate a thermal difference because
>> of
>> > >> > > difference of temps and some heating due to the physical act of
>> just
>> > >> > > inserting the plug because of friction between the jack and plug
>> (my
>> > >> theory
>> > >> > > at any rate). You have to allow at least a minute or more before
>> > >> being
>> > >> > > able
>> > >> > > to make a measurement after plugging in the leads. I just
>> measured
>> > >> the
>> > >> > > variation of the 1 volt output of my 732A and using my 3458A and
>> I
>> > >> got a
>> > >> > > total difference of 0.159 uV over 40 measurements using 100 PLC
>> on
>> > >> the
>> > >> 1
>> > >> > > volt range of the 3458A. Using the MATH function and all of the
>> data
>> > >> you
>> > >> > > can collect. That was after waiting for several minutes after
>> > >> plugging
>> > >> in
>> > >> > > the leads.
>> > >> > >
>> > >> > > I hope all of this helps.
>> > >> > >
>> > >> > > Bill
>> > >> > >
>> > >> > >
>> > >> > >
>> > >> > > ----- Original Message -----
>> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
>> > >> > > To: "Discussion of precise voltage measurement" <
>> volt-nuts@febo.com>
>> > >> > > Sent: Friday, August 22, 2014 9:03 PM
>> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
>> > >> > >
>> > >> > >
>> > >> > > > Todd,
>> > >> > > >
>> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
>> batteries
>> > >> that
>> > >> I
>> > >> > > > keep topped off and they have very low current draw (~2 to 3
>> mA at
>> > >> 13.5
>> > >> > > > VDC) when charged and at their float voltage, so I am pretty
>> sure
>> > >> they
>> > >> > > are
>> > >> > > > in good condition. I will look at getting those in the units
>> after
>> > >> I
>> > >> > > > ascertain the condition of the 732.
>> > >> > > >
>> > >> > > > So now I have a what appears to be a functioning 3458A and a
>> 732A
>> > >> but
>> > >> > > they
>> > >> > > > slightly disagree. I am like the man with two watches that
>> disagree
>> > >> on
>> > >> > > the
>> > >> > > > time - which is correct? For the moment, i am only concerned
>> with
>> > >> > > > stability. The need for absolute accuracy will come later.
>> > >> > > >
>> > >> > > > Randy
>> > >> > > >
>> > >> > > >
>> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
>> tmicallef@gmail.com
>> > >> >
>> > >> > > wrote:
>> > >> > > >
>> > >> > > > > Randy,
>> > >> > > > >
>> > >> > > > > You have two possible choices. It can be configured with 4 x
>> 6v
>> > >> 4Ah
>> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous
>> owner
>> > >> has
>> > >> > > > > modified the battery pack already. A couple of mine needed a
>> > >> nibbler
>> > >> > > tool
>> > >> > > > > to remove enough of the aluminum cover that fits over the
>> tops of
>> > >> the
>> > >> > > > > batteries. The original cover will short out to the battery
>> tabs
>> > >> > > regardless
>> > >> > > > > of the battery configuration if this is not done.
>> > >> > > > >
>> > >> > > > > You can find larger capacity batteries that will give you
>> slightly
>> > >> more
>> > >> > > > > battery life. I lost a couple sets of mail-order batteries
>> after a
>> > >> few
>> > >> > > > > extended outages. I would recommend going with locally bought
>> > >> batteries
>> > >> > > > > instead of the cheaper mail order. My local Batteries Plus
>> will
>> > >> > > typically
>> > >> > > > > have some warranty if I remember correctly. Moving forward I
>> will
>> > >> only
>> > >> > > use
>> > >> > > > > 2 12v batteries and pre-charge them on a battery charger to
>> > >> equalize
>> > >> > > them
>> > >> > > > > before putting them in the 732A. I think the cheap batteries
>> did
>> > >> not
>> > >> > > > > discharge equally, and would not recover when power was
>> applied.
>> > >> > > > >
>> > >> > > > > Inspect the back plane for damaged traces and look at the
>> > >> capacitors. I
>> > >> > > had
>> > >> > > > > a few that looked questionable. So far, I have replaced all
>> the
>> > >> big
>> > >> > > caps
>> > >> > > on
>> > >> > > > > the pre-regulator and regulator boards. My feeling is that
>> once
>> > >> these
>> > >> > > go
>> > >> > > > > online, they should run as long as possible between repairs.
>> > >> > > > >
>> > >> > > > > The battery charger circuit may need adjusting. I tweaked
>> mine and
>> > >> it
>> > >> > > > > seemed to work fine.
>> > >> > > > >
>> > >> > > > > Todd
>> > >> > > > >
>> > >> > > > >
>> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
>> > >> > > randyevans2688@gmail.com>
>> > >> > > > > wrote:
>> > >> > > > >
>> > >> > > > > > I received my Fluke 732A today. Just powered it up but it
>> needs
>> > >> new
>> > >> > > > > > batteries. Any suggestions for sources (I haven't opened
>> up the
>> > >> unit
>> > >> > > > > yet -
>> > >> > > > > > I want to make sure it works before doing that). Also
>> received
>> > >> the
>> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
>> ran
>> > >> data
>> > >> > > > > dumper
>> > >> > > > > > program to get the CAL data from my 3458A. Should be a
>> busy
>> > >> weekend.
>> > >> > > > > >
>> > >> > > > > > Randy
>> > >> > > > > > _______________________________________________
>> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
>> > >> > > > > > To unsubscribe, go to
>> > >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> > > > > > and follow the instructions there.
>> > >> > > > > >
>> > >> > > > > _______________________________________________
>> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
>> > >> > > > > To unsubscribe, go to
>> > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> > > > > and follow the instructions there.
>> > >> > > > >
>> > >> > > > _______________________________________________
>> > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
>> > >> > > > To unsubscribe, go to
>> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> > > > and follow the instructions there.
>> > >> > >
>> > >> > > _______________________________________________
>> > >> > > volt-nuts mailing list -- volt-nuts@febo.com
>> > >> > > To unsubscribe, go to
>> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> > > and follow the instructions there.
>> > >> > >
>> > >> > _______________________________________________
>> > >> > volt-nuts mailing list -- volt-nuts@febo.com
>> > >> > To unsubscribe, go to
>> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> > and follow the instructions there.
>> > >>
>> > >> _______________________________________________
>> > >> volt-nuts mailing list -- volt-nuts@febo.com
>> > >> To unsubscribe, go to
>> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > >> and follow the instructions there.
>> > >>
>> > >
>> > >
>> > _______________________________________________
>> > volt-nuts mailing list -- volt-nuts@febo.com
>> > To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> > and follow the instructions there.
>> _______________________________________________
>> volt-nuts mailing list -- volt-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>> and follow the instructions there.
>>
>
>
A
acbern@gmx.de
Wed, Aug 27, 2014 1:41 PM
well, what you do is to measure the stability of the 3458a. 1ppm drift though sounds much as overall short term average variation if your temperature is stable and your 3458a is always on. probably the temp is not stable, and that is what you see, amongst potentially some other smaller drifts like emf. before every cycle you should do an acal dcv, if you still see 10uv +/- drifts that then seems too much. (one thing I need to add is that one of my 3458a, not yet modified to have lower reference temperature, has drifts when switched on and off. that is not so much the case with modified reference. but my assumption re the above is that your meter is always on, as I said)
732a references et al do have small short term drifts, you can determine them with a josephson element (these guys told me), but the 732a is certainly very stable short term compared to a 3458a. my 732a e.g. has a drift of 0.2ppm per year.
Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans randyevans2688@gmail.com
wrote:
I am doing multiple 100 measurements simply to characterize the stability
of the 3458A and 732A units I just bought. After about 10 measurement sets
over 2 days I am seeing a variance of about .5 uV for the 10V output, or
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am already
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal)
unless the amb. temperature is really very stable (half a degree already
adds about 0.25ppm at 10v)
thanks
Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete? In
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a long
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans randyevans2688@gmail.com
wrote:
Bill,
I am trying to figure out the MATH function without much success. I
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and it
the 40 measurements and the MATH symbol shows on the display during
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of times
same result so I am doing something wrong. Is there a better source
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't have
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona
banana plugs and Belden #9272 wire. Why 9272, because it was handy
time. It is tin plated copper, shielded twisted pair 20 ga. I have
to do custom cables with 16 ga. bare copper wire that I will twist
then
put a braided shield over it. I simply cannot find what I want so I
build my own cable. I have done something like this before and it
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
used
in the past to verify my homemade "low thermal" leads as described
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals to go
away.
As far as I can tell and measure the differences, if any, are below
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
adjustable you may be seeing a misadjusted 1 volt from the 732A. As
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with the
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and mean
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press "ENTER"
then
trigger the sequence of 40 readings when I push the "ENTER" button.
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and PLC
Once those 40 readings are finished then you can access the various
statistic registers, using the menu, by entering "MATH" and then a 2
low, a 4 for mean, and 13 for high. Of course you could do all of
through the IEEE also. The 3458A has a very rich set of measurement
commands. I am still learning all of them. It depends upon what I
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived from
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and then
observe
the variations that way without the 732A involved. When I do this I
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the
side
of the measurment terminals, GUARD connected doesn't seem to affect
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method above.
would
use this to determine where your problem might exist. Just having
meter
input shorted will point you in the right direction. Meter, cables
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a small
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value of
readings are very different between the two - the 3458 reads about
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some better
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very common
as
it is used in a lot of "EXIT" signs so they are lighted when the
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the "CAL"
out when AC power is not applied. So shipping to Cal Lab can be
if it is a distance away, or you have to use a shipper like UPS
and
you ship the night before and then use their "Morning delivery"
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it up to
power" plug to last longer. I have seen it done. The issue is
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have the
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been lost
Reference Amp or other associated circuits. When the raw supply
voltage drops below about 21 volts the "CAL" light will go out.
voltage the heater circuits will not work correctly and the 18.6
regulated supply will not regulate. The requirement is that the
Amp be kept "alive" at all times to maintain the output voltage
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when power
and then power is restored the result will be a different 10
before the power failure. My experience is that after all of the
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come back to
exactly the same 10 volts as when they lost power, usually with
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the 1
output? What is the PLC set to? I always use 100 PLC to measure
you don't have "low thermal" connection leads you can experience
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between the
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference because
difference of temps and some heating due to the physical act of
inserting the plug because of friction between the jack and plug
at any rate). You have to allow at least a minute or more before
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A and
total difference of 0.159 uV over 40 measurements using 100 PLC
volt range of the 3458A. Using the MATH function and all of the
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to 3
VDC) when charged and at their float voltage, so I am pretty
in good condition. I will look at getting those in the units
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only concerned
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with 4 x
batteries or 2 x 12v 7Ah batteries. Hopefully the previous
modified the battery pack already. A couple of mine needed a
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the battery
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order batteries
extended outages. I would recommend going with locally bought
instead of the cheaper mail order. My local Batteries Plus
have some warranty if I remember correctly. Moving forward I
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap batteries
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all
the pre-regulator and regulator boards. My feeling is that
online, they should run as long as possible between repairs.
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but it
batteries. Any suggestions for sources (I haven't opened
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
well, what you do is to measure the stability of the 3458a. 1ppm drift though sounds much as overall short term average variation if your temperature is stable and your 3458a is always on. probably the temp is not stable, and that is what you see, amongst potentially some other smaller drifts like emf. before every cycle you should do an acal dcv, if you still see 10uv +/- drifts that then seems too much. (one thing I need to add is that one of my 3458a, not yet modified to have lower reference temperature, has drifts when switched on and off. that is not so much the case with modified reference. but my assumption re the above is that your meter is always on, as I said)
732a references et al do have small short term drifts, you can determine them with a josephson element (these guys told me), but the 732a is certainly very stable short term compared to a 3458a. my 732a e.g. has a drift of 0.2ppm per year.
> Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
> Von: "Randy Evans" <randyevans2688@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] 732A and Prologix received
>
> I forgot to mention that I reduced the number of measurements to 100 per
> set since I wasn't seeing much difference in the variance between 100 and
> 1000 measurements and the 1000 measurement per set takes too long.
>
> Randy
>
>
> On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans <randyevans2688@gmail.com>
> wrote:
>
> > I am doing multiple 100 measurements simply to characterize the stability
> > of the 3458A and 732A units I just bought. After about 10 measurement sets
> > over 2 days I am seeing a variance of about .5 uV for the 10V output, or
> > 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
> > that sound reasonable/
> >
> > Randy
> >
> >
> > On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
> >
> >> hi randy,
> >>
> >> just for curiosity, why doing 100 measurements at nplc 1000. is this to
> >> sample a changing value?
> >> when i am doing 10 measurements from a stable signal at nplc 100 (only
> >> there many subsequent measuremnts with statistics make sense) I am already
> >> getting a stanard deviation below 0.1ppm.
> >> in a 30 minute test cycle, i would also be concerned about drifts (acal)
> >> unless the amb. temperature is really very stable (half a degree already
> >> adds about 0.25ppm at 10v)
> >>
> >> thanks
> >>
> >>
> >>
> >>
> >> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> >> > Von: "Randy Evans" <randyevans2688@gmail.com>
> >> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> > Betreff: Re: [volt-nuts] 732A and Prologix received
> >> >
> >> > Is there any way to tell when the function key routine is complete? In
> >> the
> >> > case of taking multiple readings using the DEFKEY and MATH function, I
> >> > don't see any indication when the routine is complete. In one
> >> particular
> >> > case, I am taking a 100 readings with NLPC set for 1000 so its a long
> >> while
> >> > before it's complete, but i have to guess when it's done.
> >> >
> >> > Thanks,
> >> >
> >> > Randy
> >> >
> >> >
> >> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <randyevans2688@gmail.com>
> >> > wrote:
> >> >
> >> > > Bill,
> >> > >
> >> > > I am trying to figure out the MATH function without much success. I
> >> input
> >> > > the sequence you said (I looked up the instructions to understand
> >> what you
> >> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
> >> 4;TRIG; and
> >> > > it shows up on the display when I input BLUE F1. I hit ENTER and it
> >> takes
> >> > > the 40 measurements and the MATH symbol shows on the display during
> >> the
> >> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
> >> and I
> >> > > get a MATH ERR symbol on the display. I tried it a couple of times
> >> and the
> >> > > same result so I am doing something wrong. Is there a better source
> >> for
> >> > > explaining how to do front panel masurements than the User Guide,
> >> which
> >> > > seems oriented at programming automatic rather than manual
> >> measurements.
> >> > >
> >> > > Randy
> >> > >
> >> > >
> >> > >
> >> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
> >> wrote:
> >> > >
> >> > >> Randy:
> >> > >>
> >> > >> The MATH function is accessible from the keypad. I don't have
> >> an IEEE
> >> > >> interface right now that works. You can also program the numeric
> >> keypad
> >> > >> keys to have preprogrammed functions. DEFKEY
> >> > >>
> >> > >> I have made my own "low thermal" measurement leads from Pomona
> >> #4892
> >> > >> banana plugs and Belden #9272 wire. Why 9272, because it was handy
> >> at the
> >> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I have
> >> plans
> >> > >> to do custom cables with 16 ga. bare copper wire that I will twist
> >> and
> >> > >> then
> >> > >> put a braided shield over it. I simply cannot find what I want so I
> >> will
> >> > >> build my own cable. I have done something like this before and it
> >> worked
> >> > >> fine. When I get a "round toit".
> >> > >>
> >> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
> >> have
> >> > >> used
> >> > >> in the past to verify my homemade "low thermal" leads as described
> >> above.
> >> > >> Frankly I cannot see any difference between using the 1756 cables
> >> and my
> >> > >> homemade cables once I give them a few minutes for the thermals to go
> >> > >> away.
> >> > >> As far as I can tell and measure the differences, if any, are below
> >> 0.1
> >> > >> ppm
> >> > >> at 10 volts.
> >> > >>
> >> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
> >> are all
> >> > >> adjustable you may be seeing a misadjusted 1 volt from the 732A. As
> >> far
> >> > >> as
> >> > >> the instability of the readings it is hard to determine which is
> >> causing
> >> > >> the
> >> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with the
> >> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
> >> does is
> >> > >> set
> >> > >> the MATH to "Statistics" (store high reading/low reading/ and mean
> >> of the
> >> > >> readings) in the registers, the number of readings to "40", the
> >> trigger to
> >> > >> "hold" (which keeps the meter from triggering until I press "ENTER"
> >> and
> >> > >> then
> >> > >> trigger the sequence of 40 readings when I push the "ENTER" button.
> >> You
> >> > >> can
> >> > >> do all of this manually from the keypads but since I use this
> >> sequence a
> >> > >> lot
> >> > >> I have preprogrammed it. This is after I set digits to "8" and PLC
> >> to
> >> > >> 100.
> >> > >> Once those 40 readings are finished then you can access the various
> >> MATH
> >> > >> statistic registers, using the menu, by entering "MATH" and then a 2
> >> for
> >> > >> low, a 4 for mean, and 13 for high. Of course you could do all of
> >> this
> >> > >> through the IEEE also. The 3458A has a very rich set of measurement
> >> > >> commands. I am still learning all of them. It depends upon what I
> >> am
> >> > >> trying to accomplish.
> >> > >>
> >> > >> Since the 1.018 and 1.0 volt outputs are passive and derived from
> >> > >> resistive dividers from the 10 volt, I don't see how they could
> >> contribute
> >> > >> to the varying readings you are measuring. I think I would put a
> >> short on
> >> > >> the input of the 3458A and manually set the range to 1 volt and then
> >> > >> observe
> >> > >> the variations that way without the 732A involved. When I do this I
> >> see a
> >> > >> variation from low reading to high reading of 0.125 uVolts and then
> >> > >> another
> >> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to the
> >> low
> >> > >> side
> >> > >> of the measurment terminals, GUARD connected doesn't seem to affect
> >> the
> >> > >> readings. So that is the base noise of the 3458A without the 732A,
> >> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
> >> output I
> >> > >> got
> >> > >> a variation of 0.159 uVolts using the same 40 reading method above.
> >> I
> >> > >> would
> >> > >> use this to determine where your problem might exist. Just having
> >> the
> >> > >> meter
> >> > >> input shorted will point you in the right direction. Meter, cables
> >> or
> >> > >> 732A.
> >> > >>
> >> > >> Sorry for the long dissertation. Friends get mad at me for
> >> being so
> >> > >> detailed sometimes.
> >> > >>
> >> > >> Bill
> >> > >>
> >> > >> ----- Original Message -----
> >> > >> From: "Randy Evans" <randyevans2688@gmail.com>
> >> > >> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> > >> Sent: Sunday, August 24, 2014 7:22 AM
> >> > >> Subject: Re: [volt-nuts] 732A and Prologix received
> >> > >>
> >> > >>
> >> > >> > Bill,
> >> > >> >
> >> > >> > I have convinced myself that the problem I an seeing is due to
> >> thermals.
> >> > >> > If I move the cables (with gold-plated banana plugs) using a small
> >> > >> towel
> >> > >> > rather than letting my hand touch the plugs, it is much more
> >> stable.
> >> > >> If I
> >> > >> > then hold the banana plug with my hand after the reading has
> >> stabilized,
> >> > >> > the reading drifts rapidly upward. I am trying to check the
> >> stability
> >> > >> of
> >> > >> > the reading but I haven't figured out the MATH function yet. I
> >> assume
> >> > >> this
> >> > >> > is a programmed function using GPIB only?
> >> > >> >
> >> > >> > The stability I am seeing by manually recording readings (using
> >> NLPC of
> >> > >> 100
> >> > >> > and 1000) is much greater than what you are measuring on your
> >> system.
> >> > >> Not
> >> > >> > sure how to ascertain if it's the 3458A or the 732. The value of
> >> the
> >> > >> > readings are very different between the two - the 3458 reads about
> >> 50 uV
> >> > >> > high on the 10 V output and about 12 uV low on the 1V output.
> >> Rather
> >> > >> large
> >> > >> > differences (this is after an ACAL). I need to find some better
> >> cables
> >> > >> to
> >> > >> > make sure the errors are not due to thermals again.
> >> > >> >
> >> > >> > Randy
> >> > >> >
> >> > >> >
> >> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net>
> >> wrote:
> >> > >> >
> >> > >> > > Randy:
> >> > >> > >
> >> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
> >> will fit
> >> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
> >> LC-R064R5C and
> >> > >> > > others
> >> > >> > > that are in this size and package. Order from one of the usual
> >> > >> electronics
> >> > >> > > distributors like Allied, Mouser, Digikey. This is a very common
> >> > >> battery
> >> > >> > > as
> >> > >> > > it is used in a lot of "EXIT" signs so they are lighted when the
> >> power
> >> > >> goes
> >> > >> > > out. I don't see how the 12V 7AH will fit as they are too
> >> large. I
> >> > >> guess
> >> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
> >> volt
> >> > >> 4
> >> > >> AH
> >> > >> > > but the terminals are in the wrong place so you will have to
> >> "nibble"
> >> > >> out
> >> > >> > > the aluminum plate that holds them in the 732A battery pack.
> >> You have
> >> > >> to
> >> > >> > > be
> >> > >> > > careful if you use the 12v 5AH as you will have 4 extra battery
> >> > >> connection
> >> > >> > > leads to deal with and connect correctly. I would stick with
> >> the 6V
> >> > >> 4AH.
> >> > >> > > New batteries will last around 12 to 14 hours before the "CAL"
> >> light
> >> > >> goes
> >> > >> > > out when AC power is not applied. So shipping to Cal Lab can be
> >> a
> >> > >> problem
> >> > >> > > if it is a distance away, or you have to use a shipper like UPS
> >> or
> >> > >> FEDEX
> >> > >> > > and
> >> > >> > > you ship the night before and then use their "Morning delivery"
> >> and
> >> > >> the
> >> > >> Cal
> >> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> >> course
> >> > >> you
> >> > >> > > could always strap another battery on the 732A and hook it up to
> >> the
> >> > >> "ext
> >> > >> > > power" plug to last longer. I have seen it done. The issue is
> >> to get
> >> > >> the
> >> > >> > > Cal Lab to charge the extra battery before they ship the 732A
> >> back to
> >> > >> you.
> >> > >> > >
> >> > >> > > When you remove and work on the battery pack always have the
> >> AC
> >> > >> power
> >> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> >> regulated
> >> > >> supply
> >> > >> > > is working.
> >> > >> > >
> >> > >> > > The "CAL" light is to indicate that power has not been lost
> >> to the
> >> > >> > > Reference Amp or other associated circuits. When the raw supply
> >> > >> (battery)
> >> > >> > > voltage drops below about 21 volts the "CAL" light will go out.
> >> Below
> >> > >> that
> >> > >> > > voltage the heater circuits will not work correctly and the 18.6
> >> volt
> >> > >> > > regulated supply will not regulate. The requirement is that the
> >> > >> Reference
> >> > >> > > Amp be kept "alive" at all times to maintain the output voltage
> >> that
> >> > >> was
> >> > >> > > measured at the time of the most recent Calibration or
> >> Certification.
> >> > >> When
> >> > >> > > the semiconductor junctions are unbiased and cool off when power
> >> is
> >> > >> lost,
> >> > >> > > and then power is restored the result will be a different 10
> >> volts
> >> > >> than
> >> > >> > > before the power failure. My experience is that after all of the
> >> > >> years
> >> > >> > > that
> >> > >> > > these units have been powered up, this won't happen and when
> >> power is
> >> > >> lost
> >> > >> > > and then restored, even months later, the 732A will come back to
> >> > >> almost
> >> > >> > > exactly the same 10 volts as when they lost power, usually with
> >> in 0.2
> >> > >> PPM
> >> > >> > > after 24 hours of "warm up".
> >> > >> > >
> >> > >> > > What type of hookup leads are you using when measuring the 1
> >> volt
> >> > >> > > output? What is the PLC set to? I always use 100 PLC to measure
> >> > >> this.
> >> > >> If
> >> > >> > > you don't have "low thermal" connection leads you can experience
> >> uV
> >> > >> changes
> >> > >> > > for a minute or more after plugging in the leads due to the
> >> "thermals"
> >> > >> > > generated because of the difference in temperature between the
> >> banana
> >> > >> jacks
> >> > >> > > on the 732A and the banana plugs of the leads. I have found
> >> that even
> >> > >> just
> >> > >> > > plugging in the lead will generate a thermal difference because
> >> of
> >> > >> > > difference of temps and some heating due to the physical act of
> >> just
> >> > >> > > inserting the plug because of friction between the jack and plug
> >> (my
> >> > >> theory
> >> > >> > > at any rate). You have to allow at least a minute or more before
> >> > >> being
> >> > >> > > able
> >> > >> > > to make a measurement after plugging in the leads. I just
> >> measured
> >> > >> the
> >> > >> > > variation of the 1 volt output of my 732A and using my 3458A and
> >> I
> >> > >> got a
> >> > >> > > total difference of 0.159 uV over 40 measurements using 100 PLC
> >> on
> >> > >> the
> >> > >> 1
> >> > >> > > volt range of the 3458A. Using the MATH function and all of the
> >> data
> >> > >> you
> >> > >> > > can collect. That was after waiting for several minutes after
> >> > >> plugging
> >> > >> in
> >> > >> > > the leads.
> >> > >> > >
> >> > >> > > I hope all of this helps.
> >> > >> > >
> >> > >> > > Bill
> >> > >> > >
> >> > >> > >
> >> > >> > >
> >> > >> > > ----- Original Message -----
> >> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> >> > >> > > To: "Discussion of precise voltage measurement" <
> >> volt-nuts@febo.com>
> >> > >> > > Sent: Friday, August 22, 2014 9:03 PM
> >> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> >> > >> > >
> >> > >> > >
> >> > >> > > > Todd,
> >> > >> > > >
> >> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> >> batteries
> >> > >> that
> >> > >> I
> >> > >> > > > keep topped off and they have very low current draw (~2 to 3
> >> mA at
> >> > >> 13.5
> >> > >> > > > VDC) when charged and at their float voltage, so I am pretty
> >> sure
> >> > >> they
> >> > >> > > are
> >> > >> > > > in good condition. I will look at getting those in the units
> >> after
> >> > >> I
> >> > >> > > > ascertain the condition of the 732.
> >> > >> > > >
> >> > >> > > > So now I have a what appears to be a functioning 3458A and a
> >> 732A
> >> > >> but
> >> > >> > > they
> >> > >> > > > slightly disagree. I am like the man with two watches that
> >> disagree
> >> > >> on
> >> > >> > > the
> >> > >> > > > time - which is correct? For the moment, i am only concerned
> >> with
> >> > >> > > > stability. The need for absolute accuracy will come later.
> >> > >> > > >
> >> > >> > > > Randy
> >> > >> > > >
> >> > >> > > >
> >> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
> >> tmicallef@gmail.com
> >> > >> >
> >> > >> > > wrote:
> >> > >> > > >
> >> > >> > > > > Randy,
> >> > >> > > > >
> >> > >> > > > > You have two possible choices. It can be configured with 4 x
> >> 6v
> >> > >> 4Ah
> >> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous
> >> owner
> >> > >> has
> >> > >> > > > > modified the battery pack already. A couple of mine needed a
> >> > >> nibbler
> >> > >> > > tool
> >> > >> > > > > to remove enough of the aluminum cover that fits over the
> >> tops of
> >> > >> the
> >> > >> > > > > batteries. The original cover will short out to the battery
> >> tabs
> >> > >> > > regardless
> >> > >> > > > > of the battery configuration if this is not done.
> >> > >> > > > >
> >> > >> > > > > You can find larger capacity batteries that will give you
> >> slightly
> >> > >> more
> >> > >> > > > > battery life. I lost a couple sets of mail-order batteries
> >> after a
> >> > >> few
> >> > >> > > > > extended outages. I would recommend going with locally bought
> >> > >> batteries
> >> > >> > > > > instead of the cheaper mail order. My local Batteries Plus
> >> will
> >> > >> > > typically
> >> > >> > > > > have some warranty if I remember correctly. Moving forward I
> >> will
> >> > >> only
> >> > >> > > use
> >> > >> > > > > 2 12v batteries and pre-charge them on a battery charger to
> >> > >> equalize
> >> > >> > > them
> >> > >> > > > > before putting them in the 732A. I think the cheap batteries
> >> did
> >> > >> not
> >> > >> > > > > discharge equally, and would not recover when power was
> >> applied.
> >> > >> > > > >
> >> > >> > > > > Inspect the back plane for damaged traces and look at the
> >> > >> capacitors. I
> >> > >> > > had
> >> > >> > > > > a few that looked questionable. So far, I have replaced all
> >> the
> >> > >> big
> >> > >> > > caps
> >> > >> > > on
> >> > >> > > > > the pre-regulator and regulator boards. My feeling is that
> >> once
> >> > >> these
> >> > >> > > go
> >> > >> > > > > online, they should run as long as possible between repairs.
> >> > >> > > > >
> >> > >> > > > > The battery charger circuit may need adjusting. I tweaked
> >> mine and
> >> > >> it
> >> > >> > > > > seemed to work fine.
> >> > >> > > > >
> >> > >> > > > > Todd
> >> > >> > > > >
> >> > >> > > > >
> >> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> >> > >> > > randyevans2688@gmail.com>
> >> > >> > > > > wrote:
> >> > >> > > > >
> >> > >> > > > > > I received my Fluke 732A today. Just powered it up but it
> >> needs
> >> > >> new
> >> > >> > > > > > batteries. Any suggestions for sources (I haven't opened
> >> up the
> >> > >> unit
> >> > >> > > > > yet -
> >> > >> > > > > > I want to make sure it works before doing that). Also
> >> received
> >> > >> the
> >> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
> >> ran
> >> > >> data
> >> > >> > > > > dumper
> >> > >> > > > > > program to get the CAL data from my 3458A. Should be a
> >> busy
> >> > >> weekend.
> >> > >> > > > > >
> >> > >> > > > > > Randy
> >> > >> > > > > > _______________________________________________
> >> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > > > > To unsubscribe, go to
> >> > >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > > > > > and follow the instructions there.
> >> > >> > > > > >
> >> > >> > > > > _______________________________________________
> >> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > > > To unsubscribe, go to
> >> > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > > > > and follow the instructions there.
> >> > >> > > > >
> >> > >> > > > _______________________________________________
> >> > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > > To unsubscribe, go to
> >> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > > > and follow the instructions there.
> >> > >> > >
> >> > >> > > _______________________________________________
> >> > >> > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > To unsubscribe, go to
> >> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > > and follow the instructions there.
> >> > >> > >
> >> > >> > _______________________________________________
> >> > >> > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > To unsubscribe, go to
> >> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > and follow the instructions there.
> >> > >>
> >> > >> _______________________________________________
> >> > >> volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> To unsubscribe, go to
> >> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> and follow the instructions there.
> >> > >>
> >> > >
> >> > >
> >> > _______________________________________________
> >> > volt-nuts mailing list -- volt-nuts@febo.com
> >> > To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > and follow the instructions there.
> >> _______________________________________________
> >> volt-nuts mailing list -- volt-nuts@febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> and follow the instructions there.
> >>
> >
> >
> _______________________________________________
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> and follow the instructions there.
BG
Bill Gold
Wed, Aug 27, 2014 2:30 PM
Randy:
Something I had never tried to measure. As I have found out in the past
there is a lot of overhead going on in the meter during and after a
measurement.
In thinking about this I turned "OFF" the autozero "AZERO" and the time
for each "SMPL" was cut in half to around the estimated 16.66 seconds for
1000 PLC. So it becomes obvious that the meter makes an autozero
measurement for 1000 PLC and then the actual measurement for 1000 PLC which
explains the 33 seconds. Makes sense. This is probably why the AZERO menu
gives you ON, OFF and ONCE. For short measurement sequences you just
autozero ONCE at the start.
Thanks for the observation, this helps me. Everyday I learn something
new.
Bill
Thanks for the information
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Tuesday, August 26, 2014 2:16 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I measured the time between SMPL symbols with NPLC set to 1000 and it is
approximately 33 seconds. It takes an hour to complete 100 readings.
Randy
On Mon, Aug 25, 2014 at 10:01 PM, Bill Gold wpgold3637@att.net wrote:
Not that I know of. Just wait and when you don't see a "SMPL" on the
display it is done. But then with 1000 PLC that is around 16.66 seconds
per
reading times 100 readings is somewhere around 28 minutes and there is
probably some overhead time so around 30 minutes. Not from the front
at any rate.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Monday, August 25, 2014 9:23 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete?
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a long
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans
Bill,
I am trying to figure out the MATH function without much success. I
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and it
the 40 measurements and the MATH symbol shows on the display during
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of times
same result so I am doing something wrong. Is there a better source
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't have
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona
banana plugs and Belden #9272 wire. Why 9272, because it was handy
time. It is tin plated copper, shielded twisted pair 20 ga. I
to do custom cables with 16 ga. bare copper wire that I will twist
then
put a braided shield over it. I simply cannot find what I want so
build my own cable. I have done something like this before and it
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
used
in the past to verify my homemade "low thermal" leads as described
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals to
away.
As far as I can tell and measure the differences, if any, are below
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
adjustable you may be seeing a misadjusted 1 volt from the 732A.
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and mean
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press "ENTER"
then
trigger the sequence of 40 readings when I push the "ENTER" button.
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and PLC
Once those 40 readings are finished then you can access the various
statistic registers, using the menu, by entering "MATH" and then a
low, a 4 for mean, and 13 for high. Of course you could do all of
through the IEEE also. The 3458A has a very rich set of
commands. I am still learning all of them. It depends upon what I
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and
observe
the variations that way without the 732A involved. When I do this
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the
side
of the measurment terminals, GUARD connected doesn't seem to affect
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method above.
would
use this to determine where your problem might exist. Just having
meter
input shorted will point you in the right direction. Meter, cables
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement"
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value of
readings are very different between the two - the 3458 reads
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some better
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very
as
it is used in a lot of "EXIT" signs so they are lighted when
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2 x
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the "CAL"
out when AC power is not applied. So shipping to Cal Lab can
if it is a distance away, or you have to use a shipper like UPS
and
you ship the night before and then use their "Morning delivery"
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it up
power" plug to last longer. I have seen it done. The issue is
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been lost
Reference Amp or other associated circuits. When the raw
voltage drops below about 21 volts the "CAL" light will go out.
voltage the heater circuits will not work correctly and the
regulated supply will not regulate. The requirement is that
Amp be kept "alive" at all times to maintain the output voltage
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when
and then power is restored the result will be a different 10
before the power failure. My experience is that after all of
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come back
exactly the same 10 volts as when they lost power, usually with
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the
output? What is the PLC set to? I always use 100 PLC to
you don't have "low thermal" connection leads you can
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between the
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference because
difference of temps and some heating due to the physical act of
inserting the plug because of friction between the jack and
at any rate). You have to allow at least a minute or more
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A
total difference of 0.159 uV over 40 measurements using 100
volt range of the 3458A. Using the MATH function and all of
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement"
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to 3
VDC) when charged and at their float voltage, so I am pretty
in good condition. I will look at getting those in the units
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef
Randy,
You have two possible choices. It can be configured with 4
batteries or 2 x 12v 7Ah batteries. Hopefully the previous
modified the battery pack already. A couple of mine needed
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the battery
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order batteries
extended outages. I would recommend going with locally
instead of the cheaper mail order. My local Batteries Plus
have some warranty if I remember correctly. Moving forward
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all
the pre-regulator and regulator boards. My feeling is that
online, they should run as long as possible between
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but
batteries. Any suggestions for sources (I haven't opened
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims'
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
Randy:
Something I had never tried to measure. As I have found out in the past
there is a lot of overhead going on in the meter during and after a
measurement.
In thinking about this I turned "OFF" the autozero "AZERO" and the time
for each "SMPL" was cut in half to around the estimated 16.66 seconds for
1000 PLC. So it becomes obvious that the meter makes an autozero
measurement for 1000 PLC and then the actual measurement for 1000 PLC which
explains the 33 seconds. Makes sense. This is probably why the AZERO menu
gives you ON, OFF and ONCE. For short measurement sequences you just
autozero ONCE at the start.
Thanks for the observation, this helps me. Everyday I learn something
new.
Bill
Thanks for the information
----- Original Message -----
From: "Randy Evans" <randyevans2688@gmail.com>
To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
Sent: Tuesday, August 26, 2014 2:16 PM
Subject: Re: [volt-nuts] 732A and Prologix received
> Bill,
>
> I measured the time between SMPL symbols with NPLC set to 1000 and it is
> approximately 33 seconds. It takes an hour to complete 100 readings.
>
> Randy
>
>
> On Mon, Aug 25, 2014 at 10:01 PM, Bill Gold <wpgold3637@att.net> wrote:
>
> > Not that I know of. Just wait and when you don't see a "SMPL" on the
> > display it is done. But then with 1000 PLC that is around 16.66 seconds
> > per
> > reading times 100 readings is somewhere around 28 minutes and there is
> > probably some overhead time so around 30 minutes. Not from the front
panel
> > at any rate.
> >
> > Bill
> >
> > ----- Original Message -----
> > From: "Randy Evans" <randyevans2688@gmail.com>
> > To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > Sent: Monday, August 25, 2014 9:23 PM
> > Subject: Re: [volt-nuts] 732A and Prologix received
> >
> >
> > > Is there any way to tell when the function key routine is complete?
In
> > the
> > > case of taking multiple readings using the DEFKEY and MATH function, I
> > > don't see any indication when the routine is complete. In one
particular
> > > case, I am taking a 100 readings with NLPC set for 1000 so its a long
> > while
> > > before it's complete, but i have to guess when it's done.
> > >
> > > Thanks,
> > >
> > > Randy
> > >
> > >
> > > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans
<randyevans2688@gmail.com>
> > > wrote:
> > >
> > > > Bill,
> > > >
> > > > I am trying to figure out the MATH function without much success. I
> > input
> > > > the sequence you said (I looked up the instructions to understand
what
> > you
> > > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
4;TRIG;
> > and
> > > > it shows up on the display when I input BLUE F1. I hit ENTER and it
> > takes
> > > > the 40 measurements and the MATH symbol shows on the display during
the
> > > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
and
> > I
> > > > get a MATH ERR symbol on the display. I tried it a couple of times
and
> > the
> > > > same result so I am doing something wrong. Is there a better source
> > for
> > > > explaining how to do front panel masurements than the User Guide,
which
> > > > seems oriented at programming automatic rather than manual
> > measurements.
> > > >
> > > > Randy
> > > >
> > > >
> > > >
> > > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
wrote:
> > > >
> > > >> Randy:
> > > >>
> > > >> The MATH function is accessible from the keypad. I don't have
an
> > IEEE
> > > >> interface right now that works. You can also program the numeric
> > keypad
> > > >> keys to have preprogrammed functions. DEFKEY
> > > >>
> > > >> I have made my own "low thermal" measurement leads from Pomona
> > #4892
> > > >> banana plugs and Belden #9272 wire. Why 9272, because it was handy
at
> > the
> > > >> time. It is tin plated copper, shielded twisted pair 20 ga. I
have
> > plans
> > > >> to do custom cables with 16 ga. bare copper wire that I will twist
and
> > > >> then
> > > >> put a braided shield over it. I simply cannot find what I want so
I
> > will
> > > >> build my own cable. I have done something like this before and it
> > worked
> > > >> fine. When I get a "round toit".
> > > >>
> > > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
> > have
> > > >> used
> > > >> in the past to verify my homemade "low thermal" leads as described
> > above.
> > > >> Frankly I cannot see any difference between using the 1756 cables
and
> > my
> > > >> homemade cables once I give them a few minutes for the thermals to
go
> > > >> away.
> > > >> As far as I can tell and measure the differences, if any, are below
> > 0.1
> > > >> ppm
> > > >> at 10 volts.
> > > >>
> > > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
are
> > all
> > > >> adjustable you may be seeing a misadjusted 1 volt from the 732A.
As
> > far
> > > >> as
> > > >> the instability of the readings it is hard to determine which is
> > causing
> > > >> the
> > > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with
the
> > > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
does
> > is
> > > >> set
> > > >> the MATH to "Statistics" (store high reading/low reading/ and mean
of
> > the
> > > >> readings) in the registers, the number of readings to "40", the
> > trigger
> > to
> > > >> "hold" (which keeps the meter from triggering until I press "ENTER"
> > and
> > > >> then
> > > >> trigger the sequence of 40 readings when I push the "ENTER" button.
> > You
> > > >> can
> > > >> do all of this manually from the keypads but since I use this
sequence
> > a
> > > >> lot
> > > >> I have preprogrammed it. This is after I set digits to "8" and PLC
to
> > > >> 100.
> > > >> Once those 40 readings are finished then you can access the various
> > MATH
> > > >> statistic registers, using the menu, by entering "MATH" and then a
2
> > for
> > > >> low, a 4 for mean, and 13 for high. Of course you could do all of
> > this
> > > >> through the IEEE also. The 3458A has a very rich set of
measurement
> > > >> commands. I am still learning all of them. It depends upon what I
am
> > > >> trying to accomplish.
> > > >>
> > > >> Since the 1.018 and 1.0 volt outputs are passive and derived
from
> > > >> resistive dividers from the 10 volt, I don't see how they could
> > contribute
> > > >> to the varying readings you are measuring. I think I would put a
> > short
> > on
> > > >> the input of the 3458A and manually set the range to 1 volt and
then
> > > >> observe
> > > >> the variations that way without the 732A involved. When I do this
I
> > see a
> > > >> variation from low reading to high reading of 0.125 uVolts and then
> > > >> another
> > > >> 40 I get 0.155 uVolts. This is without the GUARD connected to the
low
> > > >> side
> > > >> of the measurment terminals, GUARD connected doesn't seem to affect
> > the
> > > >> readings. So that is the base noise of the 3458A without the 732A,
> > > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
output
> > I
> > > >> got
> > > >> a variation of 0.159 uVolts using the same 40 reading method above.
I
> > > >> would
> > > >> use this to determine where your problem might exist. Just having
the
> > > >> meter
> > > >> input shorted will point you in the right direction. Meter, cables
or
> > > >> 732A.
> > > >>
> > > >> Sorry for the long dissertation. Friends get mad at me for
being
> > so
> > > >> detailed sometimes.
> > > >>
> > > >> Bill
> > > >>
> > > >> ----- Original Message -----
> > > >> From: "Randy Evans" <randyevans2688@gmail.com>
> > > >> To: "Discussion of precise voltage measurement"
<volt-nuts@febo.com>
> > > >> Sent: Sunday, August 24, 2014 7:22 AM
> > > >> Subject: Re: [volt-nuts] 732A and Prologix received
> > > >>
> > > >>
> > > >> > Bill,
> > > >> >
> > > >> > I have convinced myself that the problem I an seeing is due to
> > thermals.
> > > >> > If I move the cables (with gold-plated banana plugs) using a
small
> > > >> towel
> > > >> > rather than letting my hand touch the plugs, it is much more
stable.
> > > >> If I
> > > >> > then hold the banana plug with my hand after the reading has
> > stabilized,
> > > >> > the reading drifts rapidly upward. I am trying to check the
> > stability
> > > >> of
> > > >> > the reading but I haven't figured out the MATH function yet. I
> > assume
> > > >> this
> > > >> > is a programmed function using GPIB only?
> > > >> >
> > > >> > The stability I am seeing by manually recording readings (using
NLPC
> > of
> > > >> 100
> > > >> > and 1000) is much greater than what you are measuring on your
> > system.
> > > >> Not
> > > >> > sure how to ascertain if it's the 3458A or the 732. The value of
> > the
> > > >> > readings are very different between the two - the 3458 reads
about
> > 50
> > uV
> > > >> > high on the 10 V output and about 12 uV low on the 1V output.
> > Rather
> > > >> large
> > > >> > differences (this is after an ACAL). I need to find some better
> > cables
> > > >> to
> > > >> > make sure the errors are not due to thermals again.
> > > >> >
> > > >> > Randy
> > > >> >
> > > >> >
> > > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net>
> > wrote:
> > > >> >
> > > >> > > Randy:
> > > >> > >
> > > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
will
> > fit
> > > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
LC-R064R5C
> > and
> > > >> > > others
> > > >> > > that are in this size and package. Order from one of the usual
> > > >> electronics
> > > >> > > distributors like Allied, Mouser, Digikey. This is a very
common
> > > >> battery
> > > >> > > as
> > > >> > > it is used in a lot of "EXIT" signs so they are lighted when
the
> > power
> > > >> goes
> > > >> > > out. I don't see how the 12V 7AH will fit as they are too
large.
> > I
> > > >> guess
> > > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x
6
> > volt
> > > >> 4
> > > >> AH
> > > >> > > but the terminals are in the wrong place so you will have to
> > "nibble"
> > > >> out
> > > >> > > the aluminum plate that holds them in the 732A battery pack.
You
> > have
> > > >> to
> > > >> > > be
> > > >> > > careful if you use the 12v 5AH as you will have 4 extra battery
> > > >> connection
> > > >> > > leads to deal with and connect correctly. I would stick with
the
> > 6V
> > > >> 4AH.
> > > >> > > New batteries will last around 12 to 14 hours before the "CAL"
> > light
> > > >> goes
> > > >> > > out when AC power is not applied. So shipping to Cal Lab can
be a
> > > >> problem
> > > >> > > if it is a distance away, or you have to use a shipper like UPS
or
> > > >> FEDEX
> > > >> > > and
> > > >> > > you ship the night before and then use their "Morning delivery"
> > and
> > > >> the
> > > >> Cal
> > > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> > course
> > > >> you
> > > >> > > could always strap another battery on the 732A and hook it up
to
> > the
> > > >> "ext
> > > >> > > power" plug to last longer. I have seen it done. The issue is
to
> > get
> > > >> the
> > > >> > > Cal Lab to charge the extra battery before they ship the 732A
back
> > to
> > > >> you.
> > > >> > >
> > > >> > > When you remove and work on the battery pack always have
the
> > AC
> > > >> power
> > > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> > regulated
> > > >> supply
> > > >> > > is working.
> > > >> > >
> > > >> > > The "CAL" light is to indicate that power has not been lost
to
> > the
> > > >> > > Reference Amp or other associated circuits. When the raw
supply
> > > >> (battery)
> > > >> > > voltage drops below about 21 volts the "CAL" light will go out.
> > Below
> > > >> that
> > > >> > > voltage the heater circuits will not work correctly and the
18.6
> > volt
> > > >> > > regulated supply will not regulate. The requirement is that
the
> > > >> Reference
> > > >> > > Amp be kept "alive" at all times to maintain the output voltage
> > that
> > > >> was
> > > >> > > measured at the time of the most recent Calibration or
> > Certification.
> > > >> When
> > > >> > > the semiconductor junctions are unbiased and cool off when
power
> > is
> > > >> lost,
> > > >> > > and then power is restored the result will be a different 10
volts
> > > >> than
> > > >> > > before the power failure. My experience is that after all of
the
> > > >> years
> > > >> > > that
> > > >> > > these units have been powered up, this won't happen and when
power
> > is
> > > >> lost
> > > >> > > and then restored, even months later, the 732A will come back
to
> > > >> almost
> > > >> > > exactly the same 10 volts as when they lost power, usually with
in
> > 0.2
> > > >> PPM
> > > >> > > after 24 hours of "warm up".
> > > >> > >
> > > >> > > What type of hookup leads are you using when measuring the
1
> > volt
> > > >> > > output? What is the PLC set to? I always use 100 PLC to
measure
> > > >> this.
> > > >> If
> > > >> > > you don't have "low thermal" connection leads you can
experience
> > uV
> > > >> changes
> > > >> > > for a minute or more after plugging in the leads due to the
> > "thermals"
> > > >> > > generated because of the difference in temperature between the
> > banana
> > > >> jacks
> > > >> > > on the 732A and the banana plugs of the leads. I have found
that
> > even
> > > >> just
> > > >> > > plugging in the lead will generate a thermal difference because
of
> > > >> > > difference of temps and some heating due to the physical act of
> > just
> > > >> > > inserting the plug because of friction between the jack and
plug
> > (my
> > > >> theory
> > > >> > > at any rate). You have to allow at least a minute or more
before
> > > >> being
> > > >> > > able
> > > >> > > to make a measurement after plugging in the leads. I just
> > measured
> > > >> the
> > > >> > > variation of the 1 volt output of my 732A and using my 3458A
and I
> > > >> got a
> > > >> > > total difference of 0.159 uV over 40 measurements using 100
PLC
> > on
> > > >> the
> > > >> 1
> > > >> > > volt range of the 3458A. Using the MATH function and all of
the
> > data
> > > >> you
> > > >> > > can collect. That was after waiting for several minutes after
> > > >> plugging
> > > >> in
> > > >> > > the leads.
> > > >> > >
> > > >> > > I hope all of this helps.
> > > >> > >
> > > >> > > Bill
> > > >> > >
> > > >> > >
> > > >> > >
> > > >> > > ----- Original Message -----
> > > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> > > >> > > To: "Discussion of precise voltage measurement"
> > <volt-nuts@febo.com>
> > > >> > > Sent: Friday, August 22, 2014 9:03 PM
> > > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> > > >> > >
> > > >> > >
> > > >> > > > Todd,
> > > >> > > >
> > > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> > batteries
> > > >> that
> > > >> I
> > > >> > > > keep topped off and they have very low current draw (~2 to 3
mA
> > at
> > > >> 13.5
> > > >> > > > VDC) when charged and at their float voltage, so I am pretty
> > sure
> > > >> they
> > > >> > > are
> > > >> > > > in good condition. I will look at getting those in the units
> > after
> > > >> I
> > > >> > > > ascertain the condition of the 732.
> > > >> > > >
> > > >> > > > So now I have a what appears to be a functioning 3458A and a
> > 732A
> > > >> but
> > > >> > > they
> > > >> > > > slightly disagree. I am like the man with two watches that
> > disagree
> > > >> on
> > > >> > > the
> > > >> > > > time - which is correct? For the moment, i am only
concerned
> > with
> > > >> > > > stability. The need for absolute accuracy will come later.
> > > >> > > >
> > > >> > > > Randy
> > > >> > > >
> > > >> > > >
> > > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef
> > <tmicallef@gmail.com
> > > >> >
> > > >> > > wrote:
> > > >> > > >
> > > >> > > > > Randy,
> > > >> > > > >
> > > >> > > > > You have two possible choices. It can be configured with 4
x
> > 6v
> > > >> 4Ah
> > > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous
> > owner
> > > >> has
> > > >> > > > > modified the battery pack already. A couple of mine needed
a
> > > >> nibbler
> > > >> > > tool
> > > >> > > > > to remove enough of the aluminum cover that fits over the
tops
> > of
> > > >> the
> > > >> > > > > batteries. The original cover will short out to the battery
> > tabs
> > > >> > > regardless
> > > >> > > > > of the battery configuration if this is not done.
> > > >> > > > >
> > > >> > > > > You can find larger capacity batteries that will give you
> > slightly
> > > >> more
> > > >> > > > > battery life. I lost a couple sets of mail-order batteries
> > after a
> > > >> few
> > > >> > > > > extended outages. I would recommend going with locally
bought
> > > >> batteries
> > > >> > > > > instead of the cheaper mail order. My local Batteries Plus
> > will
> > > >> > > typically
> > > >> > > > > have some warranty if I remember correctly. Moving forward
I
> > will
> > > >> only
> > > >> > > use
> > > >> > > > > 2 12v batteries and pre-charge them on a battery charger to
> > > >> equalize
> > > >> > > them
> > > >> > > > > before putting them in the 732A. I think the cheap
batteries
> > did
> > > >> not
> > > >> > > > > discharge equally, and would not recover when power was
> > applied.
> > > >> > > > >
> > > >> > > > > Inspect the back plane for damaged traces and look at the
> > > >> capacitors. I
> > > >> > > had
> > > >> > > > > a few that looked questionable. So far, I have replaced all
> > the
> > > >> big
> > > >> > > caps
> > > >> > > on
> > > >> > > > > the pre-regulator and regulator boards. My feeling is that
> > once
> > > >> these
> > > >> > > go
> > > >> > > > > online, they should run as long as possible between
repairs.
> > > >> > > > >
> > > >> > > > > The battery charger circuit may need adjusting. I tweaked
mine
> > and
> > > >> it
> > > >> > > > > seemed to work fine.
> > > >> > > > >
> > > >> > > > > Todd
> > > >> > > > >
> > > >> > > > >
> > > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> > > >> > > randyevans2688@gmail.com>
> > > >> > > > > wrote:
> > > >> > > > >
> > > >> > > > > > I received my Fluke 732A today. Just powered it up but
it
> > needs
> > > >> new
> > > >> > > > > > batteries. Any suggestions for sources (I haven't opened
up
> > the
> > > >> unit
> > > >> > > > > yet -
> > > >> > > > > > I want to make sure it works before doing that). Also
> > received
> > > >> the
> > > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims'
CAL
> > ran
> > > >> data
> > > >> > > > > dumper
> > > >> > > > > > program to get the CAL data from my 3458A. Should be a
busy
> > > >> weekend.
> > > >> > > > > >
> > > >> > > > > > Randy
> > > >> > > > > > _______________________________________________
> > > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > >> > > > > > To unsubscribe, go to
> > > >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > >> > > > > > and follow the instructions there.
> > > >> > > > > >
> > > >> > > > > _______________________________________________
> > > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > >> > > > > To unsubscribe, go to
> > > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > >> > > > > and follow the instructions there.
> > > >> > > > >
> > > >> > > > _______________________________________________
> > > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > >> > > > To unsubscribe, go to
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Don@True-Cal
Wed, Aug 27, 2014 2:40 PM
I have included a link to an ~30-hour measurement run that I consistently do that should give you some idea of expected measurement drift over time. Virtually all of the measurement drift is due to the 3458A internal temperature differences around the 7V reference caused by ambient temperature change. The drift associated with the 732A is probably about 2-magnitudes less at this ambient temp drift. In my situation, the inferred ambient temperature is cycling with the home air-conditioning. Note the initial calibration temperatures as well as the ACal temperatures and where the 3458A is measuring exactly 10V relative to those temperatures. My primary 732A has been powered without loss for 4 years and >5 years before that. The 3458A is Agilent (Loveland) Cal'ed yearly and is powered 24-7-365 except for the occasional mains power loss. The graphical measurements is using a homegrown Agilent VEE program. It is very helpful if not essential to get an HPIB interface setup so you can do long term graphical analysis.
The other link was done in winter time when the lab a few degrees cooler.
https://www.dropbox.com/s/8je482i3r0belqn/732A%20gold%20%26%203458A%20gold%2032-hour%20Ref%20Test%208-21-2014.pdf?dl=0
https://www.dropbox.com/s/xv3l9py7tx6hyh7/HP%20732A%20gold%20%26%203458A%20gold%207-day%2010.0v%20Ref%20Test.pdf?dl=0
I hope these Dropbox links work internationally - I'm new to using this sharing method.
Don Johnson
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@febo.com] On Behalf Of acbern@gmx.de
Sent: Wednesday, August 27, 2014 8:42 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A and Prologix received
well, what you do is to measure the stability of the 3458a. 1ppm drift though sounds much as overall short term average variation if your temperature is stable and your 3458a is always on. probably the temp is not stable, and that is what you see, amongst potentially some other smaller drifts like emf. before every cycle you should do an acal dcv, if you still see 10uv +/- drifts that then seems too much. (one thing I need to add is that one of my 3458a, not yet modified to have lower reference temperature, has drifts when switched on and off. that is not so much the case with modified reference. but my assumption re the above is that your meter is always on, as I said) 732a references et al do have small short term drifts, you can determine them with a josephson element (these guys told me), but the 732a is certainly very stable short term compared to a 3458a. my 732a e.g. has a drift of 0.2ppm per year.
Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans randyevans2688@gmail.com
wrote:
I am doing multiple 100 measurements simply to characterize the stability
of the 3458A and 732A units I just bought. After about 10 measurement sets
over 2 days I am seeing a variance of about .5 uV for the 10V output, or
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this to
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am already
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts (acal)
unless the amb. temperature is really very stable (half a degree already
adds about 0.25ppm at 10v)
thanks
Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is complete? In
case of taking multiple readings using the DEFKEY and MATH function, I
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a long
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans randyevans2688@gmail.com
wrote:
Bill,
I am trying to figure out the MATH function without much success. I
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and it
the 40 measurements and the MATH symbol shows on the display during
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of times
same result so I am doing something wrong. Is there a better source
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't have
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from Pomona
banana plugs and Belden #9272 wire. Why 9272, because it was handy
time. It is tin plated copper, shielded twisted pair 20 ga. I have
to do custom cables with 16 ga. bare copper wire that I will twist
then
put a braided shield over it. I simply cannot find what I want so I
build my own cable. I have done something like this before and it
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
used
in the past to verify my homemade "low thermal" leads as described
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals to go
away.
As far as I can tell and measure the differences, if any, are below
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
adjustable you may be seeing a misadjusted 1 volt from the 732A. As
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with the
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and mean
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press "ENTER"
then
trigger the sequence of 40 readings when I push the "ENTER" button.
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and PLC
Once those 40 readings are finished then you can access the various
statistic registers, using the menu, by entering "MATH" and then a 2
low, a 4 for mean, and 13 for high. Of course you could do all of
through the IEEE also. The 3458A has a very rich set of measurement
commands. I am still learning all of them. It depends upon what I
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived from
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and then
observe
the variations that way without the 732A involved. When I do this I
variation from low reading to high reading of 0.125 uVolts and then
another
40 I get 0.155 uVolts. This is without the GUARD connected to the
side
of the measurment terminals, GUARD connected doesn't seem to affect
readings. So that is the base noise of the 3458A without the 732A,
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method above.
would
use this to determine where your problem might exist. Just having
meter
input shorted will point you in the right direction. Meter, cables
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a small
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value of
readings are very different between the two - the 3458 reads about
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some better
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold wpgold3637@att.net
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the usual
distributors like Allied, Mouser, Digikey. This is a very common
as
it is used in a lot of "EXIT" signs so they are lighted when the
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra battery
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the "CAL"
out when AC power is not applied. So shipping to Cal Lab can be
if it is a distance away, or you have to use a shipper like UPS
and
you ship the night before and then use their "Morning delivery"
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it up to
power" plug to last longer. I have seen it done. The issue is
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have the
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been lost
Reference Amp or other associated circuits. When the raw supply
voltage drops below about 21 volts the "CAL" light will go out.
voltage the heater circuits will not work correctly and the 18.6
regulated supply will not regulate. The requirement is that the
Amp be kept "alive" at all times to maintain the output voltage
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when power
and then power is restored the result will be a different 10
before the power failure. My experience is that after all of the
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come back to
exactly the same 10 volts as when they lost power, usually with
after 24 hours of "warm up".
What type of hookup leads are you using when measuring the 1
output? What is the PLC set to? I always use 100 PLC to measure
you don't have "low thermal" connection leads you can experience
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between the
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference because
difference of temps and some heating due to the physical act of
inserting the plug because of friction between the jack and plug
at any rate). You have to allow at least a minute or more before
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A and
total difference of 0.159 uV over 40 measurements using 100 PLC
volt range of the 3458A. Using the MATH function and all of the
can collect. That was after waiting for several minutes after
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to 3
VDC) when charged and at their float voltage, so I am pretty
in good condition. I will look at getting those in the units
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only concerned
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with 4 x
batteries or 2 x 12v 7Ah batteries. Hopefully the previous
modified the battery pack already. A couple of mine needed a
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the battery
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order batteries
extended outages. I would recommend going with locally bought
instead of the cheaper mail order. My local Batteries Plus
have some warranty if I remember correctly. Moving forward I
2 12v batteries and pre-charge them on a battery charger to
before putting them in the 732A. I think the cheap batteries
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced all
the pre-regulator and regulator boards. My feeling is that
online, they should run as long as possible between repairs.
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up but it
batteries. Any suggestions for sources (I haven't opened
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
I have included a link to an ~30-hour measurement run that I consistently do that should give you some idea of expected measurement drift over time. Virtually all of the measurement drift is due to the 3458A internal temperature differences around the 7V reference caused by ambient temperature change. The drift associated with the 732A is probably about 2-magnitudes less at this ambient temp drift. In my situation, the inferred ambient temperature is cycling with the home air-conditioning. Note the initial calibration temperatures as well as the ACal temperatures and where the 3458A is measuring exactly 10V relative to those temperatures. My primary 732A has been powered without loss for 4 years and >5 years before that. The 3458A is Agilent (Loveland) Cal'ed yearly and is powered 24-7-365 except for the occasional mains power loss. The graphical measurements is using a homegrown Agilent VEE program. It is very helpful if not essential to get an HPIB interface setup so you can do long term graphical analysis.
The other link was done in winter time when the lab a few degrees cooler.
https://www.dropbox.com/s/8je482i3r0belqn/732A%20gold%20%26%203458A%20gold%2032-hour%20Ref%20Test%208-21-2014.pdf?dl=0
https://www.dropbox.com/s/xv3l9py7tx6hyh7/HP%20732A%20gold%20%26%203458A%20gold%207-day%2010.0v%20Ref%20Test.pdf?dl=0
I hope these Dropbox links work internationally - I'm new to using this sharing method.
Don Johnson
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@febo.com] On Behalf Of acbern@gmx.de
Sent: Wednesday, August 27, 2014 8:42 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A and Prologix received
well, what you do is to measure the stability of the 3458a. 1ppm drift though sounds much as overall short term average variation if your temperature is stable and your 3458a is always on. probably the temp is not stable, and that is what you see, amongst potentially some other smaller drifts like emf. before every cycle you should do an acal dcv, if you still see 10uv +/- drifts that then seems too much. (one thing I need to add is that one of my 3458a, not yet modified to have lower reference temperature, has drifts when switched on and off. that is not so much the case with modified reference. but my assumption re the above is that your meter is always on, as I said) 732a references et al do have small short term drifts, you can determine them with a josephson element (these guys told me), but the 732a is certainly very stable short term compared to a 3458a. my 732a e.g. has a drift of 0.2ppm per year.
> Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
> Von: "Randy Evans" <randyevans2688@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] 732A and Prologix received
>
> I forgot to mention that I reduced the number of measurements to 100 per
> set since I wasn't seeing much difference in the variance between 100 and
> 1000 measurements and the 1000 measurement per set takes too long.
>
> Randy
>
>
> On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans <randyevans2688@gmail.com>
> wrote:
>
> > I am doing multiple 100 measurements simply to characterize the stability
> > of the 3458A and 732A units I just bought. After about 10 measurement sets
> > over 2 days I am seeing a variance of about .5 uV for the 10V output, or
> > 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. Does
> > that sound reasonable/
> >
> > Randy
> >
> >
> > On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
> >
> >> hi randy,
> >>
> >> just for curiosity, why doing 100 measurements at nplc 1000. is this to
> >> sample a changing value?
> >> when i am doing 10 measurements from a stable signal at nplc 100 (only
> >> there many subsequent measuremnts with statistics make sense) I am already
> >> getting a stanard deviation below 0.1ppm.
> >> in a 30 minute test cycle, i would also be concerned about drifts (acal)
> >> unless the amb. temperature is really very stable (half a degree already
> >> adds about 0.25ppm at 10v)
> >>
> >> thanks
> >>
> >>
> >>
> >>
> >> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> >> > Von: "Randy Evans" <randyevans2688@gmail.com>
> >> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> > Betreff: Re: [volt-nuts] 732A and Prologix received
> >> >
> >> > Is there any way to tell when the function key routine is complete? In
> >> the
> >> > case of taking multiple readings using the DEFKEY and MATH function, I
> >> > don't see any indication when the routine is complete. In one
> >> particular
> >> > case, I am taking a 100 readings with NLPC set for 1000 so its a long
> >> while
> >> > before it's complete, but i have to guess when it's done.
> >> >
> >> > Thanks,
> >> >
> >> > Randy
> >> >
> >> >
> >> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <randyevans2688@gmail.com>
> >> > wrote:
> >> >
> >> > > Bill,
> >> > >
> >> > > I am trying to figure out the MATH function without much success. I
> >> input
> >> > > the sequence you said (I looked up the instructions to understand
> >> what you
> >> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
> >> 4;TRIG; and
> >> > > it shows up on the display when I input BLUE F1. I hit ENTER and it
> >> takes
> >> > > the 40 measurements and the MATH symbol shows on the display during
> >> the
> >> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
> >> and I
> >> > > get a MATH ERR symbol on the display. I tried it a couple of times
> >> and the
> >> > > same result so I am doing something wrong. Is there a better source
> >> for
> >> > > explaining how to do front panel masurements than the User Guide,
> >> which
> >> > > seems oriented at programming automatic rather than manual
> >> measurements.
> >> > >
> >> > > Randy
> >> > >
> >> > >
> >> > >
> >> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
> >> wrote:
> >> > >
> >> > >> Randy:
> >> > >>
> >> > >> The MATH function is accessible from the keypad. I don't have
> >> an IEEE
> >> > >> interface right now that works. You can also program the numeric
> >> keypad
> >> > >> keys to have preprogrammed functions. DEFKEY
> >> > >>
> >> > >> I have made my own "low thermal" measurement leads from Pomona
> >> #4892
> >> > >> banana plugs and Belden #9272 wire. Why 9272, because it was handy
> >> at the
> >> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I have
> >> plans
> >> > >> to do custom cables with 16 ga. bare copper wire that I will twist
> >> and
> >> > >> then
> >> > >> put a braided shield over it. I simply cannot find what I want so I
> >> will
> >> > >> build my own cable. I have done something like this before and it
> >> worked
> >> > >> fine. When I get a "round toit".
> >> > >>
> >> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that I
> >> have
> >> > >> used
> >> > >> in the past to verify my homemade "low thermal" leads as described
> >> above.
> >> > >> Frankly I cannot see any difference between using the 1756 cables
> >> and my
> >> > >> homemade cables once I give them a few minutes for the thermals to go
> >> > >> away.
> >> > >> As far as I can tell and measure the differences, if any, are below
> >> 0.1
> >> > >> ppm
> >> > >> at 10 volts.
> >> > >>
> >> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A
> >> are all
> >> > >> adjustable you may be seeing a misadjusted 1 volt from the 732A. As
> >> far
> >> > >> as
> >> > >> the instability of the readings it is hard to determine which is
> >> causing
> >> > >> the
> >> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with the
> >> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
> >> does is
> >> > >> set
> >> > >> the MATH to "Statistics" (store high reading/low reading/ and mean
> >> of the
> >> > >> readings) in the registers, the number of readings to "40", the
> >> trigger to
> >> > >> "hold" (which keeps the meter from triggering until I press "ENTER"
> >> and
> >> > >> then
> >> > >> trigger the sequence of 40 readings when I push the "ENTER" button.
> >> You
> >> > >> can
> >> > >> do all of this manually from the keypads but since I use this
> >> sequence a
> >> > >> lot
> >> > >> I have preprogrammed it. This is after I set digits to "8" and PLC
> >> to
> >> > >> 100.
> >> > >> Once those 40 readings are finished then you can access the various
> >> MATH
> >> > >> statistic registers, using the menu, by entering "MATH" and then a 2
> >> for
> >> > >> low, a 4 for mean, and 13 for high. Of course you could do all of
> >> this
> >> > >> through the IEEE also. The 3458A has a very rich set of measurement
> >> > >> commands. I am still learning all of them. It depends upon what I
> >> am
> >> > >> trying to accomplish.
> >> > >>
> >> > >> Since the 1.018 and 1.0 volt outputs are passive and derived from
> >> > >> resistive dividers from the 10 volt, I don't see how they could
> >> contribute
> >> > >> to the varying readings you are measuring. I think I would put a
> >> short on
> >> > >> the input of the 3458A and manually set the range to 1 volt and then
> >> > >> observe
> >> > >> the variations that way without the 732A involved. When I do this I
> >> see a
> >> > >> variation from low reading to high reading of 0.125 uVolts and then
> >> > >> another
> >> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to the
> >> low
> >> > >> side
> >> > >> of the measurment terminals, GUARD connected doesn't seem to affect
> >> the
> >> > >> readings. So that is the base noise of the 3458A without the 732A,
> >> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
> >> output I
> >> > >> got
> >> > >> a variation of 0.159 uVolts using the same 40 reading method above.
> >> I
> >> > >> would
> >> > >> use this to determine where your problem might exist. Just having
> >> the
> >> > >> meter
> >> > >> input shorted will point you in the right direction. Meter, cables
> >> or
> >> > >> 732A.
> >> > >>
> >> > >> Sorry for the long dissertation. Friends get mad at me for
> >> being so
> >> > >> detailed sometimes.
> >> > >>
> >> > >> Bill
> >> > >>
> >> > >> ----- Original Message -----
> >> > >> From: "Randy Evans" <randyevans2688@gmail.com>
> >> > >> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> >> > >> Sent: Sunday, August 24, 2014 7:22 AM
> >> > >> Subject: Re: [volt-nuts] 732A and Prologix received
> >> > >>
> >> > >>
> >> > >> > Bill,
> >> > >> >
> >> > >> > I have convinced myself that the problem I an seeing is due to
> >> thermals.
> >> > >> > If I move the cables (with gold-plated banana plugs) using a small
> >> > >> towel
> >> > >> > rather than letting my hand touch the plugs, it is much more
> >> stable.
> >> > >> If I
> >> > >> > then hold the banana plug with my hand after the reading has
> >> stabilized,
> >> > >> > the reading drifts rapidly upward. I am trying to check the
> >> stability
> >> > >> of
> >> > >> > the reading but I haven't figured out the MATH function yet. I
> >> assume
> >> > >> this
> >> > >> > is a programmed function using GPIB only?
> >> > >> >
> >> > >> > The stability I am seeing by manually recording readings (using
> >> NLPC of
> >> > >> 100
> >> > >> > and 1000) is much greater than what you are measuring on your
> >> system.
> >> > >> Not
> >> > >> > sure how to ascertain if it's the 3458A or the 732. The value of
> >> the
> >> > >> > readings are very different between the two - the 3458 reads about
> >> 50 uV
> >> > >> > high on the 10 V output and about 12 uV low on the 1V output.
> >> Rather
> >> > >> large
> >> > >> > differences (this is after an ACAL). I need to find some better
> >> cables
> >> > >> to
> >> > >> > make sure the errors are not due to thermals again.
> >> > >> >
> >> > >> > Randy
> >> > >> >
> >> > >> >
> >> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <wpgold3637@att.net>
> >> wrote:
> >> > >> >
> >> > >> > > Randy:
> >> > >> > >
> >> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
> >> will fit
> >> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
> >> LC-R064R5C and
> >> > >> > > others
> >> > >> > > that are in this size and package. Order from one of the usual
> >> > >> electronics
> >> > >> > > distributors like Allied, Mouser, Digikey. This is a very common
> >> > >> battery
> >> > >> > > as
> >> > >> > > it is used in a lot of "EXIT" signs so they are lighted when the
> >> power
> >> > >> goes
> >> > >> > > out. I don't see how the 12V 7AH will fit as they are too
> >> large. I
> >> > >> guess
> >> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2 x 6
> >> volt
> >> > >> 4
> >> > >> AH
> >> > >> > > but the terminals are in the wrong place so you will have to
> >> "nibble"
> >> > >> out
> >> > >> > > the aluminum plate that holds them in the 732A battery pack.
> >> You have
> >> > >> to
> >> > >> > > be
> >> > >> > > careful if you use the 12v 5AH as you will have 4 extra battery
> >> > >> connection
> >> > >> > > leads to deal with and connect correctly. I would stick with
> >> the 6V
> >> > >> 4AH.
> >> > >> > > New batteries will last around 12 to 14 hours before the "CAL"
> >> light
> >> > >> goes
> >> > >> > > out when AC power is not applied. So shipping to Cal Lab can be
> >> a
> >> > >> problem
> >> > >> > > if it is a distance away, or you have to use a shipper like UPS
> >> or
> >> > >> FEDEX
> >> > >> > > and
> >> > >> > > you ship the night before and then use their "Morning delivery"
> >> and
> >> > >> the
> >> > >> Cal
> >> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> >> course
> >> > >> you
> >> > >> > > could always strap another battery on the 732A and hook it up to
> >> the
> >> > >> "ext
> >> > >> > > power" plug to last longer. I have seen it done. The issue is
> >> to get
> >> > >> the
> >> > >> > > Cal Lab to charge the extra battery before they ship the 732A
> >> back to
> >> > >> you.
> >> > >> > >
> >> > >> > > When you remove and work on the battery pack always have the
> >> AC
> >> > >> power
> >> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> >> regulated
> >> > >> supply
> >> > >> > > is working.
> >> > >> > >
> >> > >> > > The "CAL" light is to indicate that power has not been lost
> >> to the
> >> > >> > > Reference Amp or other associated circuits. When the raw supply
> >> > >> (battery)
> >> > >> > > voltage drops below about 21 volts the "CAL" light will go out.
> >> Below
> >> > >> that
> >> > >> > > voltage the heater circuits will not work correctly and the 18.6
> >> volt
> >> > >> > > regulated supply will not regulate. The requirement is that the
> >> > >> Reference
> >> > >> > > Amp be kept "alive" at all times to maintain the output voltage
> >> that
> >> > >> was
> >> > >> > > measured at the time of the most recent Calibration or
> >> Certification.
> >> > >> When
> >> > >> > > the semiconductor junctions are unbiased and cool off when power
> >> is
> >> > >> lost,
> >> > >> > > and then power is restored the result will be a different 10
> >> volts
> >> > >> than
> >> > >> > > before the power failure. My experience is that after all of the
> >> > >> years
> >> > >> > > that
> >> > >> > > these units have been powered up, this won't happen and when
> >> power is
> >> > >> lost
> >> > >> > > and then restored, even months later, the 732A will come back to
> >> > >> almost
> >> > >> > > exactly the same 10 volts as when they lost power, usually with
> >> in 0.2
> >> > >> PPM
> >> > >> > > after 24 hours of "warm up".
> >> > >> > >
> >> > >> > > What type of hookup leads are you using when measuring the 1
> >> volt
> >> > >> > > output? What is the PLC set to? I always use 100 PLC to measure
> >> > >> this.
> >> > >> If
> >> > >> > > you don't have "low thermal" connection leads you can experience
> >> uV
> >> > >> changes
> >> > >> > > for a minute or more after plugging in the leads due to the
> >> "thermals"
> >> > >> > > generated because of the difference in temperature between the
> >> banana
> >> > >> jacks
> >> > >> > > on the 732A and the banana plugs of the leads. I have found
> >> that even
> >> > >> just
> >> > >> > > plugging in the lead will generate a thermal difference because
> >> of
> >> > >> > > difference of temps and some heating due to the physical act of
> >> just
> >> > >> > > inserting the plug because of friction between the jack and plug
> >> (my
> >> > >> theory
> >> > >> > > at any rate). You have to allow at least a minute or more before
> >> > >> being
> >> > >> > > able
> >> > >> > > to make a measurement after plugging in the leads. I just
> >> measured
> >> > >> the
> >> > >> > > variation of the 1 volt output of my 732A and using my 3458A and
> >> I
> >> > >> got a
> >> > >> > > total difference of 0.159 uV over 40 measurements using 100 PLC
> >> on
> >> > >> the
> >> > >> 1
> >> > >> > > volt range of the 3458A. Using the MATH function and all of the
> >> data
> >> > >> you
> >> > >> > > can collect. That was after waiting for several minutes after
> >> > >> plugging
> >> > >> in
> >> > >> > > the leads.
> >> > >> > >
> >> > >> > > I hope all of this helps.
> >> > >> > >
> >> > >> > > Bill
> >> > >> > >
> >> > >> > >
> >> > >> > >
> >> > >> > > ----- Original Message -----
> >> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> >> > >> > > To: "Discussion of precise voltage measurement" <
> >> volt-nuts@febo.com>
> >> > >> > > Sent: Friday, August 22, 2014 9:03 PM
> >> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> >> > >> > >
> >> > >> > >
> >> > >> > > > Todd,
> >> > >> > > >
> >> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> >> batteries
> >> > >> that
> >> > >> I
> >> > >> > > > keep topped off and they have very low current draw (~2 to 3
> >> mA at
> >> > >> 13.5
> >> > >> > > > VDC) when charged and at their float voltage, so I am pretty
> >> sure
> >> > >> they
> >> > >> > > are
> >> > >> > > > in good condition. I will look at getting those in the units
> >> after
> >> > >> I
> >> > >> > > > ascertain the condition of the 732.
> >> > >> > > >
> >> > >> > > > So now I have a what appears to be a functioning 3458A and a
> >> 732A
> >> > >> but
> >> > >> > > they
> >> > >> > > > slightly disagree. I am like the man with two watches that
> >> disagree
> >> > >> on
> >> > >> > > the
> >> > >> > > > time - which is correct? For the moment, i am only concerned
> >> with
> >> > >> > > > stability. The need for absolute accuracy will come later.
> >> > >> > > >
> >> > >> > > > Randy
> >> > >> > > >
> >> > >> > > >
> >> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
> >> tmicallef@gmail.com
> >> > >> >
> >> > >> > > wrote:
> >> > >> > > >
> >> > >> > > > > Randy,
> >> > >> > > > >
> >> > >> > > > > You have two possible choices. It can be configured with 4 x
> >> 6v
> >> > >> 4Ah
> >> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the previous
> >> owner
> >> > >> has
> >> > >> > > > > modified the battery pack already. A couple of mine needed a
> >> > >> nibbler
> >> > >> > > tool
> >> > >> > > > > to remove enough of the aluminum cover that fits over the
> >> tops of
> >> > >> the
> >> > >> > > > > batteries. The original cover will short out to the battery
> >> tabs
> >> > >> > > regardless
> >> > >> > > > > of the battery configuration if this is not done.
> >> > >> > > > >
> >> > >> > > > > You can find larger capacity batteries that will give you
> >> slightly
> >> > >> more
> >> > >> > > > > battery life. I lost a couple sets of mail-order batteries
> >> after a
> >> > >> few
> >> > >> > > > > extended outages. I would recommend going with locally bought
> >> > >> batteries
> >> > >> > > > > instead of the cheaper mail order. My local Batteries Plus
> >> will
> >> > >> > > typically
> >> > >> > > > > have some warranty if I remember correctly. Moving forward I
> >> will
> >> > >> only
> >> > >> > > use
> >> > >> > > > > 2 12v batteries and pre-charge them on a battery charger to
> >> > >> equalize
> >> > >> > > them
> >> > >> > > > > before putting them in the 732A. I think the cheap batteries
> >> did
> >> > >> not
> >> > >> > > > > discharge equally, and would not recover when power was
> >> applied.
> >> > >> > > > >
> >> > >> > > > > Inspect the back plane for damaged traces and look at the
> >> > >> capacitors. I
> >> > >> > > had
> >> > >> > > > > a few that looked questionable. So far, I have replaced all
> >> the
> >> > >> big
> >> > >> > > caps
> >> > >> > > on
> >> > >> > > > > the pre-regulator and regulator boards. My feeling is that
> >> once
> >> > >> these
> >> > >> > > go
> >> > >> > > > > online, they should run as long as possible between repairs.
> >> > >> > > > >
> >> > >> > > > > The battery charger circuit may need adjusting. I tweaked
> >> mine and
> >> > >> it
> >> > >> > > > > seemed to work fine.
> >> > >> > > > >
> >> > >> > > > > Todd
> >> > >> > > > >
> >> > >> > > > >
> >> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> >> > >> > > randyevans2688@gmail.com>
> >> > >> > > > > wrote:
> >> > >> > > > >
> >> > >> > > > > > I received my Fluke 732A today. Just powered it up but it
> >> needs
> >> > >> new
> >> > >> > > > > > batteries. Any suggestions for sources (I haven't opened
> >> up the
> >> > >> unit
> >> > >> > > > > yet -
> >> > >> > > > > > I want to make sure it works before doing that). Also
> >> received
> >> > >> the
> >> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' CAL
> >> ran
> >> > >> data
> >> > >> > > > > dumper
> >> > >> > > > > > program to get the CAL data from my 3458A. Should be a
> >> busy
> >> > >> weekend.
> >> > >> > > > > >
> >> > >> > > > > > Randy
> >> > >> > > > > > _______________________________________________
> >> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > > > > To unsubscribe, go to
> >> > >> > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> >> > >> > > > > > and follow the instructions there.
> >> > >> > > > > >
> >> > >> > > > > _______________________________________________
> >> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> >> > >> > > > > To unsubscribe, go to
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> >> > >> > > > > and follow the instructions there.
> >> > >> > > > >
> >> > >> > > > _______________________________________________
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> >> > >> > > _______________________________________________
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and follow the instructions there.
RE
Randy Evans
Wed, Aug 27, 2014 3:37 PM
The HP3458A and the Fluke 732A are on continuously and I do an ACAL at
least every few hours, or when the room temperature changes by more than 1
degree C. The total range of measurements is 10uV so the drift is +/-5uV,
or 0.5 ppm. The room temperature is not particularly stable and varies
over a 3C range. The internal temp of the 3458 varies from 38.1 to 40.3
degrees C over the set of measurements. The 732A thermistor resistance
measures from 3.6677 Kohms to 3.6686 Kohms. I am using copper wires
between the 3458A and the 752A to minimize thermals. At the moment I have
no way to tell which unit is drifting the most.
Randy
On Wed, Aug 27, 2014 at 6:41 AM, acbern@gmx.de wrote:
well, what you do is to measure the stability of the 3458a. 1ppm drift
though sounds much as overall short term average variation if your
temperature is stable and your 3458a is always on. probably the temp is not
stable, and that is what you see, amongst potentially some other smaller
drifts like emf. before every cycle you should do an acal dcv, if you still
see 10uv +/- drifts that then seems too much. (one thing I need to add is
that one of my 3458a, not yet modified to have lower reference temperature,
has drifts when switched on and off. that is not so much the case with
modified reference. but my assumption re the above is that your meter is
always on, as I said)
732a references et al do have small short term drifts, you can determine
them with a josephson element (these guys told me), but the 732a is
certainly very stable short term compared to a 3458a. my 732a e.g. has a
drift of 0.2ppm per year.
Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans randyevans2688@gmail.com
wrote:
I am doing multiple 100 measurements simply to characterize the
of the 3458A and 732A units I just bought. After about 10 measurement
over 2 days I am seeing a variance of about .5 uV for the 10V output,
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm.
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts
unless the amb. temperature is really very stable (half a degree
adds about 0.25ppm at 10v)
thanks
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is
case of taking multiple readings using the DEFKEY and MATH
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <
Bill,
I am trying to figure out the MATH function without much
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and
the 40 measurements and the MATH symbol shows on the display
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of
same result so I am doing something wrong. Is there a better
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from
banana plugs and Belden #9272 wire. Why 9272, because it was
time. It is tin plated copper, shielded twisted pair 20 ga. I
to do custom cables with 16 ga. bare copper wire that I will
then
put a braided shield over it. I simply cannot find what I want
build my own cable. I have done something like this before and
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that
used
in the past to verify my homemade "low thermal" leads as
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals
away.
As far as I can tell and measure the differences, if any, are
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the
adjustable you may be seeing a misadjusted 1 volt from the
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press
then
trigger the sequence of 40 readings when I push the "ENTER"
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and
Once those 40 readings are finished then you can access the
statistic registers, using the menu, by entering "MATH" and then
low, a 4 for mean, and 13 for high. Of course you could do all
through the IEEE also. The 3458A has a very rich set of
commands. I am still learning all of them. It depends upon
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and
observe
the variations that way without the 732A involved. When I do
variation from low reading to high reading of 0.125 uVolts and
another
40 I get 0.155 uVolts. This is without the GUARD connected to
side
of the measurment terminals, GUARD connected doesn't seem to
readings. So that is the base noise of the 3458A without the
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method
would
use this to determine where your problem might exist. Just
meter
input shorted will point you in the right direction. Meter,
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value
readings are very different between the two - the 3458 reads
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the
distributors like Allied, Mouser, Digikey. This is a very
as
it is used in a lot of "EXIT" signs so they are lighted when
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the
out when AC power is not applied. So shipping to Cal Lab
if it is a distance away, or you have to use a shipper like
and
you ship the night before and then use their "Morning
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it
power" plug to last longer. I have seen it done. The issue
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been
Reference Amp or other associated circuits. When the raw
voltage drops below about 21 volts the "CAL" light will go
voltage the heater circuits will not work correctly and the
regulated supply will not regulate. The requirement is that
Amp be kept "alive" at all times to maintain the output
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when
and then power is restored the result will be a different 10
before the power failure. My experience is that after all
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come
exactly the same 10 volts as when they lost power, usually
after 24 hours of "warm up".
What type of hookup leads are you using when measuring
output? What is the PLC set to? I always use 100 PLC to
you don't have "low thermal" connection leads you can
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference
difference of temps and some heating due to the physical act
inserting the plug because of friction between the jack and
at any rate). You have to allow at least a minute or more
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A
total difference of 0.159 uV over 40 measurements using 100
volt range of the 3458A. Using the MATH function and all of
can collect. That was after waiting for several minutes
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to
VDC) when charged and at their float voltage, so I am
in good condition. I will look at getting those in the
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with
batteries or 2 x 12v 7Ah batteries. Hopefully the
modified the battery pack already. A couple of mine
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order
extended outages. I would recommend going with locally
instead of the cheaper mail order. My local Batteries
have some warranty if I remember correctly. Moving
2 12v batteries and pre-charge them on a battery charger
before putting them in the 732A. I think the cheap
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced
the pre-regulator and regulator boards. My feeling is
online, they should run as long as possible between
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up
batteries. Any suggestions for sources (I haven't
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims'
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
The HP3458A and the Fluke 732A are on continuously and I do an ACAL at
least every few hours, or when the room temperature changes by more than 1
degree C. The total range of measurements is 10uV so the drift is +/-5uV,
or 0.5 ppm. The room temperature is not particularly stable and varies
over a 3C range. The internal temp of the 3458 varies from 38.1 to 40.3
degrees C over the set of measurements. The 732A thermistor resistance
measures from 3.6677 Kohms to 3.6686 Kohms. I am using copper wires
between the 3458A and the 752A to minimize thermals. At the moment I have
no way to tell which unit is drifting the most.
Randy
On Wed, Aug 27, 2014 at 6:41 AM, <acbern@gmx.de> wrote:
> well, what you do is to measure the stability of the 3458a. 1ppm drift
> though sounds much as overall short term average variation if your
> temperature is stable and your 3458a is always on. probably the temp is not
> stable, and that is what you see, amongst potentially some other smaller
> drifts like emf. before every cycle you should do an acal dcv, if you still
> see 10uv +/- drifts that then seems too much. (one thing I need to add is
> that one of my 3458a, not yet modified to have lower reference temperature,
> has drifts when switched on and off. that is not so much the case with
> modified reference. but my assumption re the above is that your meter is
> always on, as I said)
> 732a references et al do have small short term drifts, you can determine
> them with a josephson element (these guys told me), but the 732a is
> certainly very stable short term compared to a 3458a. my 732a e.g. has a
> drift of 0.2ppm per year.
>
>
> > Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
> > Von: "Randy Evans" <randyevans2688@gmail.com>
> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > Betreff: Re: [volt-nuts] 732A and Prologix received
> >
> > I forgot to mention that I reduced the number of measurements to 100 per
> > set since I wasn't seeing much difference in the variance between 100 and
> > 1000 measurements and the 1000 measurement per set takes too long.
> >
> > Randy
> >
> >
> > On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans <randyevans2688@gmail.com>
> > wrote:
> >
> > > I am doing multiple 100 measurements simply to characterize the
> stability
> > > of the 3458A and 732A units I just bought. After about 10 measurement
> sets
> > > over 2 days I am seeing a variance of about .5 uV for the 10V output,
> or
> > > 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm.
> Does
> > > that sound reasonable/
> > >
> > > Randy
> > >
> > >
> > > On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
> > >
> > >> hi randy,
> > >>
> > >> just for curiosity, why doing 100 measurements at nplc 1000. is this
> to
> > >> sample a changing value?
> > >> when i am doing 10 measurements from a stable signal at nplc 100 (only
> > >> there many subsequent measuremnts with statistics make sense) I am
> already
> > >> getting a stanard deviation below 0.1ppm.
> > >> in a 30 minute test cycle, i would also be concerned about drifts
> (acal)
> > >> unless the amb. temperature is really very stable (half a degree
> already
> > >> adds about 0.25ppm at 10v)
> > >>
> > >> thanks
> > >>
> > >>
> > >>
> > >>
> > >> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> > >> > Von: "Randy Evans" <randyevans2688@gmail.com>
> > >> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com
> >
> > >> > Betreff: Re: [volt-nuts] 732A and Prologix received
> > >> >
> > >> > Is there any way to tell when the function key routine is
> complete? In
> > >> the
> > >> > case of taking multiple readings using the DEFKEY and MATH
> function, I
> > >> > don't see any indication when the routine is complete. In one
> > >> particular
> > >> > case, I am taking a 100 readings with NLPC set for 1000 so its a
> long
> > >> while
> > >> > before it's complete, but i have to guess when it's done.
> > >> >
> > >> > Thanks,
> > >> >
> > >> > Randy
> > >> >
> > >> >
> > >> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <
> randyevans2688@gmail.com>
> > >> > wrote:
> > >> >
> > >> > > Bill,
> > >> > >
> > >> > > I am trying to figure out the MATH function without much
> success. I
> > >> input
> > >> > > the sequence you said (I looked up the instructions to understand
> > >> what you
> > >> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
> > >> 4;TRIG; and
> > >> > > it shows up on the display when I input BLUE F1. I hit ENTER and
> it
> > >> takes
> > >> > > the 40 measurements and the MATH symbol shows on the display
> during
> > >> the
> > >> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
> > >> and I
> > >> > > get a MATH ERR symbol on the display. I tried it a couple of
> times
> > >> and the
> > >> > > same result so I am doing something wrong. Is there a better
> source
> > >> for
> > >> > > explaining how to do front panel masurements than the User Guide,
> > >> which
> > >> > > seems oriented at programming automatic rather than manual
> > >> measurements.
> > >> > >
> > >> > > Randy
> > >> > >
> > >> > >
> > >> > >
> > >> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
> > >> wrote:
> > >> > >
> > >> > >> Randy:
> > >> > >>
> > >> > >> The MATH function is accessible from the keypad. I don't
> have
> > >> an IEEE
> > >> > >> interface right now that works. You can also program the numeric
> > >> keypad
> > >> > >> keys to have preprogrammed functions. DEFKEY
> > >> > >>
> > >> > >> I have made my own "low thermal" measurement leads from
> Pomona
> > >> #4892
> > >> > >> banana plugs and Belden #9272 wire. Why 9272, because it was
> handy
> > >> at the
> > >> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I
> have
> > >> plans
> > >> > >> to do custom cables with 16 ga. bare copper wire that I will
> twist
> > >> and
> > >> > >> then
> > >> > >> put a braided shield over it. I simply cannot find what I want
> so I
> > >> will
> > >> > >> build my own cable. I have done something like this before and
> it
> > >> worked
> > >> > >> fine. When I get a "round toit".
> > >> > >>
> > >> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that
> I
> > >> have
> > >> > >> used
> > >> > >> in the past to verify my homemade "low thermal" leads as
> described
> > >> above.
> > >> > >> Frankly I cannot see any difference between using the 1756 cables
> > >> and my
> > >> > >> homemade cables once I give them a few minutes for the thermals
> to go
> > >> > >> away.
> > >> > >> As far as I can tell and measure the differences, if any, are
> below
> > >> 0.1
> > >> > >> ppm
> > >> > >> at 10 volts.
> > >> > >>
> > >> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the
> 732A
> > >> are all
> > >> > >> adjustable you may be seeing a misadjusted 1 volt from the
> 732A. As
> > >> far
> > >> > >> as
> > >> > >> the instability of the readings it is hard to determine which is
> > >> causing
> > >> > >> the
> > >> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with
> the
> > >> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
> > >> does is
> > >> > >> set
> > >> > >> the MATH to "Statistics" (store high reading/low reading/ and
> mean
> > >> of the
> > >> > >> readings) in the registers, the number of readings to "40", the
> > >> trigger to
> > >> > >> "hold" (which keeps the meter from triggering until I press
> "ENTER"
> > >> and
> > >> > >> then
> > >> > >> trigger the sequence of 40 readings when I push the "ENTER"
> button.
> > >> You
> > >> > >> can
> > >> > >> do all of this manually from the keypads but since I use this
> > >> sequence a
> > >> > >> lot
> > >> > >> I have preprogrammed it. This is after I set digits to "8" and
> PLC
> > >> to
> > >> > >> 100.
> > >> > >> Once those 40 readings are finished then you can access the
> various
> > >> MATH
> > >> > >> statistic registers, using the menu, by entering "MATH" and then
> a 2
> > >> for
> > >> > >> low, a 4 for mean, and 13 for high. Of course you could do all
> of
> > >> this
> > >> > >> through the IEEE also. The 3458A has a very rich set of
> measurement
> > >> > >> commands. I am still learning all of them. It depends upon
> what I
> > >> am
> > >> > >> trying to accomplish.
> > >> > >>
> > >> > >> Since the 1.018 and 1.0 volt outputs are passive and derived
> from
> > >> > >> resistive dividers from the 10 volt, I don't see how they could
> > >> contribute
> > >> > >> to the varying readings you are measuring. I think I would put a
> > >> short on
> > >> > >> the input of the 3458A and manually set the range to 1 volt and
> then
> > >> > >> observe
> > >> > >> the variations that way without the 732A involved. When I do
> this I
> > >> see a
> > >> > >> variation from low reading to high reading of 0.125 uVolts and
> then
> > >> > >> another
> > >> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to
> the
> > >> low
> > >> > >> side
> > >> > >> of the measurment terminals, GUARD connected doesn't seem to
> affect
> > >> the
> > >> > >> readings. So that is the base noise of the 3458A without the
> 732A,
> > >> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
> > >> output I
> > >> > >> got
> > >> > >> a variation of 0.159 uVolts using the same 40 reading method
> above.
> > >> I
> > >> > >> would
> > >> > >> use this to determine where your problem might exist. Just
> having
> > >> the
> > >> > >> meter
> > >> > >> input shorted will point you in the right direction. Meter,
> cables
> > >> or
> > >> > >> 732A.
> > >> > >>
> > >> > >> Sorry for the long dissertation. Friends get mad at me for
> > >> being so
> > >> > >> detailed sometimes.
> > >> > >>
> > >> > >> Bill
> > >> > >>
> > >> > >> ----- Original Message -----
> > >> > >> From: "Randy Evans" <randyevans2688@gmail.com>
> > >> > >> To: "Discussion of precise voltage measurement" <
> volt-nuts@febo.com>
> > >> > >> Sent: Sunday, August 24, 2014 7:22 AM
> > >> > >> Subject: Re: [volt-nuts] 732A and Prologix received
> > >> > >>
> > >> > >>
> > >> > >> > Bill,
> > >> > >> >
> > >> > >> > I have convinced myself that the problem I an seeing is due to
> > >> thermals.
> > >> > >> > If I move the cables (with gold-plated banana plugs) using a
> small
> > >> > >> towel
> > >> > >> > rather than letting my hand touch the plugs, it is much more
> > >> stable.
> > >> > >> If I
> > >> > >> > then hold the banana plug with my hand after the reading has
> > >> stabilized,
> > >> > >> > the reading drifts rapidly upward. I am trying to check the
> > >> stability
> > >> > >> of
> > >> > >> > the reading but I haven't figured out the MATH function yet. I
> > >> assume
> > >> > >> this
> > >> > >> > is a programmed function using GPIB only?
> > >> > >> >
> > >> > >> > The stability I am seeing by manually recording readings (using
> > >> NLPC of
> > >> > >> 100
> > >> > >> > and 1000) is much greater than what you are measuring on your
> > >> system.
> > >> > >> Not
> > >> > >> > sure how to ascertain if it's the 3458A or the 732. The value
> of
> > >> the
> > >> > >> > readings are very different between the two - the 3458 reads
> about
> > >> 50 uV
> > >> > >> > high on the 10 V output and about 12 uV low on the 1V output.
> > >> Rather
> > >> > >> large
> > >> > >> > differences (this is after an ACAL). I need to find some
> better
> > >> cables
> > >> > >> to
> > >> > >> > make sure the errors are not due to thermals again.
> > >> > >> >
> > >> > >> > Randy
> > >> > >> >
> > >> > >> >
> > >> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <
> wpgold3637@att.net>
> > >> wrote:
> > >> > >> >
> > >> > >> > > Randy:
> > >> > >> > >
> > >> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
> > >> will fit
> > >> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
> > >> LC-R064R5C and
> > >> > >> > > others
> > >> > >> > > that are in this size and package. Order from one of the
> usual
> > >> > >> electronics
> > >> > >> > > distributors like Allied, Mouser, Digikey. This is a very
> common
> > >> > >> battery
> > >> > >> > > as
> > >> > >> > > it is used in a lot of "EXIT" signs so they are lighted when
> the
> > >> power
> > >> > >> goes
> > >> > >> > > out. I don't see how the 12V 7AH will fit as they are too
> > >> large. I
> > >> > >> guess
> > >> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2
> x 6
> > >> volt
> > >> > >> 4
> > >> > >> AH
> > >> > >> > > but the terminals are in the wrong place so you will have to
> > >> "nibble"
> > >> > >> out
> > >> > >> > > the aluminum plate that holds them in the 732A battery pack.
> > >> You have
> > >> > >> to
> > >> > >> > > be
> > >> > >> > > careful if you use the 12v 5AH as you will have 4 extra
> battery
> > >> > >> connection
> > >> > >> > > leads to deal with and connect correctly. I would stick with
> > >> the 6V
> > >> > >> 4AH.
> > >> > >> > > New batteries will last around 12 to 14 hours before the
> "CAL"
> > >> light
> > >> > >> goes
> > >> > >> > > out when AC power is not applied. So shipping to Cal Lab
> can be
> > >> a
> > >> > >> problem
> > >> > >> > > if it is a distance away, or you have to use a shipper like
> UPS
> > >> or
> > >> > >> FEDEX
> > >> > >> > > and
> > >> > >> > > you ship the night before and then use their "Morning
> delivery"
> > >> and
> > >> > >> the
> > >> > >> Cal
> > >> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> > >> course
> > >> > >> you
> > >> > >> > > could always strap another battery on the 732A and hook it
> up to
> > >> the
> > >> > >> "ext
> > >> > >> > > power" plug to last longer. I have seen it done. The issue
> is
> > >> to get
> > >> > >> the
> > >> > >> > > Cal Lab to charge the extra battery before they ship the 732A
> > >> back to
> > >> > >> you.
> > >> > >> > >
> > >> > >> > > When you remove and work on the battery pack always have
> the
> > >> AC
> > >> > >> power
> > >> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> > >> regulated
> > >> > >> supply
> > >> > >> > > is working.
> > >> > >> > >
> > >> > >> > > The "CAL" light is to indicate that power has not been
> lost
> > >> to the
> > >> > >> > > Reference Amp or other associated circuits. When the raw
> supply
> > >> > >> (battery)
> > >> > >> > > voltage drops below about 21 volts the "CAL" light will go
> out.
> > >> Below
> > >> > >> that
> > >> > >> > > voltage the heater circuits will not work correctly and the
> 18.6
> > >> volt
> > >> > >> > > regulated supply will not regulate. The requirement is that
> the
> > >> > >> Reference
> > >> > >> > > Amp be kept "alive" at all times to maintain the output
> voltage
> > >> that
> > >> > >> was
> > >> > >> > > measured at the time of the most recent Calibration or
> > >> Certification.
> > >> > >> When
> > >> > >> > > the semiconductor junctions are unbiased and cool off when
> power
> > >> is
> > >> > >> lost,
> > >> > >> > > and then power is restored the result will be a different 10
> > >> volts
> > >> > >> than
> > >> > >> > > before the power failure. My experience is that after all
> of the
> > >> > >> years
> > >> > >> > > that
> > >> > >> > > these units have been powered up, this won't happen and when
> > >> power is
> > >> > >> lost
> > >> > >> > > and then restored, even months later, the 732A will come
> back to
> > >> > >> almost
> > >> > >> > > exactly the same 10 volts as when they lost power, usually
> with
> > >> in 0.2
> > >> > >> PPM
> > >> > >> > > after 24 hours of "warm up".
> > >> > >> > >
> > >> > >> > > What type of hookup leads are you using when measuring
> the 1
> > >> volt
> > >> > >> > > output? What is the PLC set to? I always use 100 PLC to
> measure
> > >> > >> this.
> > >> > >> If
> > >> > >> > > you don't have "low thermal" connection leads you can
> experience
> > >> uV
> > >> > >> changes
> > >> > >> > > for a minute or more after plugging in the leads due to the
> > >> "thermals"
> > >> > >> > > generated because of the difference in temperature between
> the
> > >> banana
> > >> > >> jacks
> > >> > >> > > on the 732A and the banana plugs of the leads. I have found
> > >> that even
> > >> > >> just
> > >> > >> > > plugging in the lead will generate a thermal difference
> because
> > >> of
> > >> > >> > > difference of temps and some heating due to the physical act
> of
> > >> just
> > >> > >> > > inserting the plug because of friction between the jack and
> plug
> > >> (my
> > >> > >> theory
> > >> > >> > > at any rate). You have to allow at least a minute or more
> before
> > >> > >> being
> > >> > >> > > able
> > >> > >> > > to make a measurement after plugging in the leads. I just
> > >> measured
> > >> > >> the
> > >> > >> > > variation of the 1 volt output of my 732A and using my 3458A
> and
> > >> I
> > >> > >> got a
> > >> > >> > > total difference of 0.159 uV over 40 measurements using 100
> PLC
> > >> on
> > >> > >> the
> > >> > >> 1
> > >> > >> > > volt range of the 3458A. Using the MATH function and all of
> the
> > >> data
> > >> > >> you
> > >> > >> > > can collect. That was after waiting for several minutes
> after
> > >> > >> plugging
> > >> > >> in
> > >> > >> > > the leads.
> > >> > >> > >
> > >> > >> > > I hope all of this helps.
> > >> > >> > >
> > >> > >> > > Bill
> > >> > >> > >
> > >> > >> > >
> > >> > >> > >
> > >> > >> > > ----- Original Message -----
> > >> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> > >> > >> > > To: "Discussion of precise voltage measurement" <
> > >> volt-nuts@febo.com>
> > >> > >> > > Sent: Friday, August 22, 2014 9:03 PM
> > >> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> > >> > >> > >
> > >> > >> > >
> > >> > >> > > > Todd,
> > >> > >> > > >
> > >> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> > >> batteries
> > >> > >> that
> > >> > >> I
> > >> > >> > > > keep topped off and they have very low current draw (~2 to
> 3
> > >> mA at
> > >> > >> 13.5
> > >> > >> > > > VDC) when charged and at their float voltage, so I am
> pretty
> > >> sure
> > >> > >> they
> > >> > >> > > are
> > >> > >> > > > in good condition. I will look at getting those in the
> units
> > >> after
> > >> > >> I
> > >> > >> > > > ascertain the condition of the 732.
> > >> > >> > > >
> > >> > >> > > > So now I have a what appears to be a functioning 3458A and
> a
> > >> 732A
> > >> > >> but
> > >> > >> > > they
> > >> > >> > > > slightly disagree. I am like the man with two watches that
> > >> disagree
> > >> > >> on
> > >> > >> > > the
> > >> > >> > > > time - which is correct? For the moment, i am only
> concerned
> > >> with
> > >> > >> > > > stability. The need for absolute accuracy will come later.
> > >> > >> > > >
> > >> > >> > > > Randy
> > >> > >> > > >
> > >> > >> > > >
> > >> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
> > >> tmicallef@gmail.com
> > >> > >> >
> > >> > >> > > wrote:
> > >> > >> > > >
> > >> > >> > > > > Randy,
> > >> > >> > > > >
> > >> > >> > > > > You have two possible choices. It can be configured with
> 4 x
> > >> 6v
> > >> > >> 4Ah
> > >> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the
> previous
> > >> owner
> > >> > >> has
> > >> > >> > > > > modified the battery pack already. A couple of mine
> needed a
> > >> > >> nibbler
> > >> > >> > > tool
> > >> > >> > > > > to remove enough of the aluminum cover that fits over the
> > >> tops of
> > >> > >> the
> > >> > >> > > > > batteries. The original cover will short out to the
> battery
> > >> tabs
> > >> > >> > > regardless
> > >> > >> > > > > of the battery configuration if this is not done.
> > >> > >> > > > >
> > >> > >> > > > > You can find larger capacity batteries that will give you
> > >> slightly
> > >> > >> more
> > >> > >> > > > > battery life. I lost a couple sets of mail-order
> batteries
> > >> after a
> > >> > >> few
> > >> > >> > > > > extended outages. I would recommend going with locally
> bought
> > >> > >> batteries
> > >> > >> > > > > instead of the cheaper mail order. My local Batteries
> Plus
> > >> will
> > >> > >> > > typically
> > >> > >> > > > > have some warranty if I remember correctly. Moving
> forward I
> > >> will
> > >> > >> only
> > >> > >> > > use
> > >> > >> > > > > 2 12v batteries and pre-charge them on a battery charger
> to
> > >> > >> equalize
> > >> > >> > > them
> > >> > >> > > > > before putting them in the 732A. I think the cheap
> batteries
> > >> did
> > >> > >> not
> > >> > >> > > > > discharge equally, and would not recover when power was
> > >> applied.
> > >> > >> > > > >
> > >> > >> > > > > Inspect the back plane for damaged traces and look at the
> > >> > >> capacitors. I
> > >> > >> > > had
> > >> > >> > > > > a few that looked questionable. So far, I have replaced
> all
> > >> the
> > >> > >> big
> > >> > >> > > caps
> > >> > >> > > on
> > >> > >> > > > > the pre-regulator and regulator boards. My feeling is
> that
> > >> once
> > >> > >> these
> > >> > >> > > go
> > >> > >> > > > > online, they should run as long as possible between
> repairs.
> > >> > >> > > > >
> > >> > >> > > > > The battery charger circuit may need adjusting. I tweaked
> > >> mine and
> > >> > >> it
> > >> > >> > > > > seemed to work fine.
> > >> > >> > > > >
> > >> > >> > > > > Todd
> > >> > >> > > > >
> > >> > >> > > > >
> > >> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> > >> > >> > > randyevans2688@gmail.com>
> > >> > >> > > > > wrote:
> > >> > >> > > > >
> > >> > >> > > > > > I received my Fluke 732A today. Just powered it up
> but it
> > >> needs
> > >> > >> new
> > >> > >> > > > > > batteries. Any suggestions for sources (I haven't
> opened
> > >> up the
> > >> > >> unit
> > >> > >> > > > > yet -
> > >> > >> > > > > > I want to make sure it works before doing that). Also
> > >> received
> > >> > >> the
> > >> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims'
> CAL
> > >> ran
> > >> > >> data
> > >> > >> > > > > dumper
> > >> > >> > > > > > program to get the CAL data from my 3458A. Should be a
> > >> busy
> > >> > >> weekend.
> > >> > >> > > > > >
> > >> > >> > > > > > Randy
> > >> > >> > > > > > _______________________________________________
> > >> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > > > To unsubscribe, go to
> > >> > >> > > > > >
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > > > and follow the instructions there.
> > >> > >> > > > > >
> > >> > >> > > > > _______________________________________________
> > >> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > > To unsubscribe, go to
> > >> > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > > and follow the instructions there.
> > >> > >> > > > >
> > >> > >> > > > _______________________________________________
> > >> > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > To unsubscribe, go to
> > >> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > and follow the instructions there.
> > >> > >> > >
> > >> > >> > > _______________________________________________
> > >> > >> > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > To unsubscribe, go to
> > >> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > and follow the instructions there.
> > >> > >> > >
> > >> > >> > _______________________________________________
> > >> > >> > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > To unsubscribe, go to
> > >> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > and follow the instructions there.
> > >> > >>
> > >> > >> _______________________________________________
> > >> > >> volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> To unsubscribe, go to
> > >> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> and follow the instructions there.
> > >> > >>
> > >> > >
> > >> > >
> > >> > _______________________________________________
> > >> > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > To unsubscribe, go to
> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > and follow the instructions there.
> > >> _______________________________________________
> > >> volt-nuts mailing list -- volt-nuts@febo.com
> > >> To unsubscribe, go to
> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> and follow the instructions there.
> > >>
> > >
> > >
> > _______________________________________________
> > volt-nuts mailing list -- volt-nuts@febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> _______________________________________________
> volt-nuts mailing list -- volt-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
>
RE
Randy Evans
Wed, Aug 27, 2014 3:49 PM
Don,
If I am reading your charts correctly, it looks like your system is cycling
over an 7 uV range over several days in summer, similar to what I am
seeing. I don't have air conditioning (Northern California) so I do get
some pretty good temperature variations from day to night, but less inside
the house.
I need to figure out how to share files in Dropbox since I don't have my
own web site. Good idea.
thanks,
Randy
On Wed, Aug 27, 2014 at 7:40 AM, Don@True-Cal truecalservices@gmail.com
wrote:
I have included a link to an ~30-hour measurement run that I consistently
do that should give you some idea of expected measurement drift over time.
Virtually all of the measurement drift is due to the 3458A internal
temperature differences around the 7V reference caused by ambient
temperature change. The drift associated with the 732A is probably about
2-magnitudes less at this ambient temp drift. In my situation, the inferred
ambient temperature is cycling with the home air-conditioning. Note the
initial calibration temperatures as well as the ACal temperatures and where
the 3458A is measuring exactly 10V relative to those temperatures. My
primary 732A has been powered without loss for 4 years and >5 years before
that. The 3458A is Agilent (Loveland) Cal'ed yearly and is powered 24-7-365
except for the occasional mains power loss. The graphical measurements is
using a homegrown Agilent VEE program. It is very helpful if not essential
to get an HPIB interface setup so you can do long term graphical analysis.
The other link was done in winter time when the lab a few degrees cooler.
https://www.dropbox.com/s/8je482i3r0belqn/732A%20gold%20%26%203458A%20gold%2032-hour%20Ref%20Test%208-21-2014.pdf?dl=0
https://www.dropbox.com/s/xv3l9py7tx6hyh7/HP%20732A%20gold%20%26%203458A%20gold%207-day%2010.0v%20Ref%20Test.pdf?dl=0
I hope these Dropbox links work internationally - I'm new to using this
sharing method.
Don Johnson
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@febo.com] On Behalf Of
acbern@gmx.de
Sent: Wednesday, August 27, 2014 8:42 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A and Prologix received
well, what you do is to measure the stability of the 3458a. 1ppm drift
though sounds much as overall short term average variation if your
temperature is stable and your 3458a is always on. probably the temp is not
stable, and that is what you see, amongst potentially some other smaller
drifts like emf. before every cycle you should do an acal dcv, if you still
see 10uv +/- drifts that then seems too much. (one thing I need to add is
that one of my 3458a, not yet modified to have lower reference temperature,
has drifts when switched on and off. that is not so much the case with
modified reference. but my assumption re the above is that your meter is
always on, as I said) 732a references et al do have small short term
drifts, you can determine them with a josephson element (these guys told
me), but the 732a is certainly very stable short term compared to a 3458a.
my 732a e.g. has a drift of 0.2ppm per year.
Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "Discussion of precise voltage measurement" volt-nuts@febo.com
Betreff: Re: [volt-nuts] 732A and Prologix received
I forgot to mention that I reduced the number of measurements to 100 per
set since I wasn't seeing much difference in the variance between 100 and
1000 measurements and the 1000 measurement per set takes too long.
Randy
On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans randyevans2688@gmail.com
wrote:
I am doing multiple 100 measurements simply to characterize the
of the 3458A and 732A units I just bought. After about 10 measurement
over 2 days I am seeing a variance of about .5 uV for the 10V output,
0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm.
that sound reasonable/
Randy
On Tue, Aug 26, 2014 at 5:41 PM, acbern@gmx.de wrote:
hi randy,
just for curiosity, why doing 100 measurements at nplc 1000. is this
sample a changing value?
when i am doing 10 measurements from a stable signal at nplc 100 (only
there many subsequent measuremnts with statistics make sense) I am
getting a stanard deviation below 0.1ppm.
in a 30 minute test cycle, i would also be concerned about drifts
unless the amb. temperature is really very stable (half a degree
adds about 0.25ppm at 10v)
thanks
Betreff: Re: [volt-nuts] 732A and Prologix received
Is there any way to tell when the function key routine is
case of taking multiple readings using the DEFKEY and MATH
don't see any indication when the routine is complete. In one
case, I am taking a 100 readings with NLPC set for 1000 so its a
before it's complete, but i have to guess when it's done.
Thanks,
Randy
On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <
Bill,
I am trying to figure out the MATH function without much
the sequence you said (I looked up the instructions to understand
did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
it shows up on the display when I input BLUE F1. I hit ENTER and
the 40 measurements and the MATH symbol shows on the display
measurements. After the SMPL symbol no longer blinks I hit MATH 2
get a MATH ERR symbol on the display. I tried it a couple of
same result so I am doing something wrong. Is there a better
explaining how to do front panel masurements than the User Guide,
seems oriented at programming automatic rather than manual
Randy:
The MATH function is accessible from the keypad. I don't
interface right now that works. You can also program the numeric
keys to have preprogrammed functions. DEFKEY
I have made my own "low thermal" measurement leads from
banana plugs and Belden #9272 wire. Why 9272, because it was
time. It is tin plated copper, shielded twisted pair 20 ga. I
to do custom cables with 16 ga. bare copper wire that I will
then
put a braided shield over it. I simply cannot find what I want
build my own cable. I have done something like this before and
fine. When I get a "round toit".
I have 6 ea. Pomona 1756-48 spade lug low thermal leads that
used
in the past to verify my homemade "low thermal" leads as
Frankly I cannot see any difference between using the 1756 cables
homemade cables once I give them a few minutes for the thermals
away.
As far as I can tell and measure the differences, if any, are
ppm
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the
adjustable you may be seeing a misadjusted 1 volt from the
as
the instability of the readings it is hard to determine which is
the
problem. I have programed (DEFKEY) a numeric keypad key #1 with
following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
set
the MATH to "Statistics" (store high reading/low reading/ and
readings) in the registers, the number of readings to "40", the
"hold" (which keeps the meter from triggering until I press
then
trigger the sequence of 40 readings when I push the "ENTER"
can
do all of this manually from the keypads but since I use this
lot
I have preprogrammed it. This is after I set digits to "8" and
Once those 40 readings are finished then you can access the
statistic registers, using the menu, by entering "MATH" and then
low, a 4 for mean, and 13 for high. Of course you could do all
through the IEEE also. The 3458A has a very rich set of
commands. I am still learning all of them. It depends upon
trying to accomplish.
Since the 1.018 and 1.0 volt outputs are passive and derived
resistive dividers from the 10 volt, I don't see how they could
to the varying readings you are measuring. I think I would put a
the input of the 3458A and manually set the range to 1 volt and
observe
the variations that way without the 732A involved. When I do
variation from low reading to high reading of 0.125 uVolts and
another
40 I get 0.155 uVolts. This is without the GUARD connected to
side
of the measurment terminals, GUARD connected doesn't seem to
readings. So that is the base noise of the 3458A without the
somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
got
a variation of 0.159 uVolts using the same 40 reading method
would
use this to determine where your problem might exist. Just
meter
input shorted will point you in the right direction. Meter,
732A.
Sorry for the long dissertation. Friends get mad at me for
detailed sometimes.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Sunday, August 24, 2014 7:22 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I have convinced myself that the problem I an seeing is due to
If I move the cables (with gold-plated banana plugs) using a
rather than letting my hand touch the plugs, it is much more
then hold the banana plug with my hand after the reading has
the reading drifts rapidly upward. I am trying to check the
the reading but I haven't figured out the MATH function yet. I
is a programmed function using GPIB only?
The stability I am seeing by manually recording readings (using
and 1000) is much greater than what you are measuring on your
sure how to ascertain if it's the 3458A or the 732. The value
readings are very different between the two - the 3458 reads
high on the 10 V output and about 12 uV low on the 1V output.
differences (this is after an ACAL). I need to find some
make sure the errors are not due to thermals again.
Randy
On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <
Randy:
I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
others
that are in this size and package. Order from one of the
distributors like Allied, Mouser, Digikey. This is a very
as
it is used in a lot of "EXIT" signs so they are lighted when
out. I don't see how the 12V 7AH will fit as they are too
you could use a 12V 5AH (PS1250) as it is the same size as 2
but the terminals are in the wrong place so you will have to
the aluminum plate that holds them in the 732A battery pack.
be
careful if you use the 12v 5AH as you will have 4 extra
leads to deal with and connect correctly. I would stick with
New batteries will last around 12 to 14 hours before the
out when AC power is not applied. So shipping to Cal Lab
if it is a distance away, or you have to use a shipper like
and
you ship the night before and then use their "Morning
Lab is expecting your 732A. Same on the way back to you. Of
could always strap another battery on the 732A and hook it
power" plug to last longer. I have seen it done. The issue
Cal Lab to charge the extra battery before they ship the 732A
When you remove and work on the battery pack always have
plugged in. The "CAL" led will stay on because the 18.6 v
is working.
The "CAL" light is to indicate that power has not been
Reference Amp or other associated circuits. When the raw
voltage drops below about 21 volts the "CAL" light will go
voltage the heater circuits will not work correctly and the
regulated supply will not regulate. The requirement is that
Amp be kept "alive" at all times to maintain the output
measured at the time of the most recent Calibration or
the semiconductor junctions are unbiased and cool off when
and then power is restored the result will be a different 10
before the power failure. My experience is that after all
that
these units have been powered up, this won't happen and when
and then restored, even months later, the 732A will come
exactly the same 10 volts as when they lost power, usually
after 24 hours of "warm up".
What type of hookup leads are you using when measuring
output? What is the PLC set to? I always use 100 PLC to
you don't have "low thermal" connection leads you can
for a minute or more after plugging in the leads due to the
generated because of the difference in temperature between
on the 732A and the banana plugs of the leads. I have found
plugging in the lead will generate a thermal difference
difference of temps and some heating due to the physical act
inserting the plug because of friction between the jack and
at any rate). You have to allow at least a minute or more
able
to make a measurement after plugging in the leads. I just
variation of the 1 volt output of my 732A and using my 3458A
total difference of 0.159 uV over 40 measurements using 100
volt range of the 3458A. Using the MATH function and all of
can collect. That was after waiting for several minutes
the leads.
I hope all of this helps.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" <
Sent: Friday, August 22, 2014 9:03 PM
Subject: Re: [volt-nuts] 732A and Prologix received
Todd,
Thanks for the info. I have several Panasonic 12V 7 AH
keep topped off and they have very low current draw (~2 to
VDC) when charged and at their float voltage, so I am
in good condition. I will look at getting those in the
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and
slightly disagree. I am like the man with two watches that
time - which is correct? For the moment, i am only
stability. The need for absolute accuracy will come later.
Randy
On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
Randy,
You have two possible choices. It can be configured with
batteries or 2 x 12v 7Ah batteries. Hopefully the
modified the battery pack already. A couple of mine
to remove enough of the aluminum cover that fits over the
batteries. The original cover will short out to the
of the battery configuration if this is not done.
You can find larger capacity batteries that will give you
battery life. I lost a couple sets of mail-order
extended outages. I would recommend going with locally
instead of the cheaper mail order. My local Batteries
have some warranty if I remember correctly. Moving
2 12v batteries and pre-charge them on a battery charger
before putting them in the 732A. I think the cheap
discharge equally, and would not recover when power was
Inspect the back plane for damaged traces and look at the
a few that looked questionable. So far, I have replaced
the pre-regulator and regulator boards. My feeling is
online, they should run as long as possible between
The battery charger circuit may need adjusting. I tweaked
seemed to work fine.
Todd
On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
I received my Fluke 732A today. Just powered it up
batteries. Any suggestions for sources (I haven't
I want to make sure it works before doing that). Also
ProLogix USB-GPIB adapter. I plan on using Mark Sims'
program to get the CAL data from my 3458A. Should be a
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
and follow the instructions there.
Don,
If I am reading your charts correctly, it looks like your system is cycling
over an 7 uV range over several days in summer, similar to what I am
seeing. I don't have air conditioning (Northern California) so I do get
some pretty good temperature variations from day to night, but less inside
the house.
I need to figure out how to share files in Dropbox since I don't have my
own web site. Good idea.
thanks,
Randy
On Wed, Aug 27, 2014 at 7:40 AM, Don@True-Cal <truecalservices@gmail.com>
wrote:
> I have included a link to an ~30-hour measurement run that I consistently
> do that should give you some idea of expected measurement drift over time.
> Virtually all of the measurement drift is due to the 3458A internal
> temperature differences around the 7V reference caused by ambient
> temperature change. The drift associated with the 732A is probably about
> 2-magnitudes less at this ambient temp drift. In my situation, the inferred
> ambient temperature is cycling with the home air-conditioning. Note the
> initial calibration temperatures as well as the ACal temperatures and where
> the 3458A is measuring exactly 10V relative to those temperatures. My
> primary 732A has been powered without loss for 4 years and >5 years before
> that. The 3458A is Agilent (Loveland) Cal'ed yearly and is powered 24-7-365
> except for the occasional mains power loss. The graphical measurements is
> using a homegrown Agilent VEE program. It is very helpful if not essential
> to get an HPIB interface setup so you can do long term graphical analysis.
>
> The other link was done in winter time when the lab a few degrees cooler.
>
>
> https://www.dropbox.com/s/8je482i3r0belqn/732A%20gold%20%26%203458A%20gold%2032-hour%20Ref%20Test%208-21-2014.pdf?dl=0
>
>
> https://www.dropbox.com/s/xv3l9py7tx6hyh7/HP%20732A%20gold%20%26%203458A%20gold%207-day%2010.0v%20Ref%20Test.pdf?dl=0
>
> I hope these Dropbox links work internationally - I'm new to using this
> sharing method.
>
> Don Johnson
>
> -----Original Message-----
> From: volt-nuts [mailto:volt-nuts-bounces@febo.com] On Behalf Of
> acbern@gmx.de
> Sent: Wednesday, August 27, 2014 8:42 AM
> To: Discussion of precise voltage measurement
> Subject: Re: [volt-nuts] 732A and Prologix received
>
> well, what you do is to measure the stability of the 3458a. 1ppm drift
> though sounds much as overall short term average variation if your
> temperature is stable and your 3458a is always on. probably the temp is not
> stable, and that is what you see, amongst potentially some other smaller
> drifts like emf. before every cycle you should do an acal dcv, if you still
> see 10uv +/- drifts that then seems too much. (one thing I need to add is
> that one of my 3458a, not yet modified to have lower reference temperature,
> has drifts when switched on and off. that is not so much the case with
> modified reference. but my assumption re the above is that your meter is
> always on, as I said) 732a references et al do have small short term
> drifts, you can determine them with a josephson element (these guys told
> me), but the 732a is certainly very stable short term compared to a 3458a.
> my 732a e.g. has a drift of 0.2ppm per year.
>
>
> > Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr
> > Von: "Randy Evans" <randyevans2688@gmail.com>
> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > Betreff: Re: [volt-nuts] 732A and Prologix received
> >
> > I forgot to mention that I reduced the number of measurements to 100 per
> > set since I wasn't seeing much difference in the variance between 100 and
> > 1000 measurements and the 1000 measurement per set takes too long.
> >
> > Randy
> >
> >
> > On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans <randyevans2688@gmail.com>
> > wrote:
> >
> > > I am doing multiple 100 measurements simply to characterize the
> stability
> > > of the 3458A and 732A units I just bought. After about 10 measurement
> sets
> > > over 2 days I am seeing a variance of about .5 uV for the 10V output,
> or
> > > 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm.
> Does
> > > that sound reasonable/
> > >
> > > Randy
> > >
> > >
> > > On Tue, Aug 26, 2014 at 5:41 PM, <acbern@gmx.de> wrote:
> > >
> > >> hi randy,
> > >>
> > >> just for curiosity, why doing 100 measurements at nplc 1000. is this
> to
> > >> sample a changing value?
> > >> when i am doing 10 measurements from a stable signal at nplc 100 (only
> > >> there many subsequent measuremnts with statistics make sense) I am
> already
> > >> getting a stanard deviation below 0.1ppm.
> > >> in a 30 minute test cycle, i would also be concerned about drifts
> (acal)
> > >> unless the amb. temperature is really very stable (half a degree
> already
> > >> adds about 0.25ppm at 10v)
> > >>
> > >> thanks
> > >>
> > >>
> > >>
> > >>
> > >> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr
> > >> > Von: "Randy Evans" <randyevans2688@gmail.com>
> > >> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com
> >
> > >> > Betreff: Re: [volt-nuts] 732A and Prologix received
> > >> >
> > >> > Is there any way to tell when the function key routine is
> complete? In
> > >> the
> > >> > case of taking multiple readings using the DEFKEY and MATH
> function, I
> > >> > don't see any indication when the routine is complete. In one
> > >> particular
> > >> > case, I am taking a 100 readings with NLPC set for 1000 so its a
> long
> > >> while
> > >> > before it's complete, but i have to guess when it's done.
> > >> >
> > >> > Thanks,
> > >> >
> > >> > Randy
> > >> >
> > >> >
> > >> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans <
> randyevans2688@gmail.com>
> > >> > wrote:
> > >> >
> > >> > > Bill,
> > >> > >
> > >> > > I am trying to figure out the MATH function without much
> success. I
> > >> input
> > >> > > the sequence you said (I looked up the instructions to understand
> > >> what you
> > >> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS 40;TRIG
> > >> 4;TRIG; and
> > >> > > it shows up on the display when I input BLUE F1. I hit ENTER and
> it
> > >> takes
> > >> > > the 40 measurements and the MATH symbol shows on the display
> during
> > >> the
> > >> > > measurements. After the SMPL symbol no longer blinks I hit MATH 2
> > >> and I
> > >> > > get a MATH ERR symbol on the display. I tried it a couple of
> times
> > >> and the
> > >> > > same result so I am doing something wrong. Is there a better
> source
> > >> for
> > >> > > explaining how to do front panel masurements than the User Guide,
> > >> which
> > >> > > seems oriented at programming automatic rather than manual
> > >> measurements.
> > >> > >
> > >> > > Randy
> > >> > >
> > >> > >
> > >> > >
> > >> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold <wpgold3637@att.net>
> > >> wrote:
> > >> > >
> > >> > >> Randy:
> > >> > >>
> > >> > >> The MATH function is accessible from the keypad. I don't
> have
> > >> an IEEE
> > >> > >> interface right now that works. You can also program the numeric
> > >> keypad
> > >> > >> keys to have preprogrammed functions. DEFKEY
> > >> > >>
> > >> > >> I have made my own "low thermal" measurement leads from
> Pomona
> > >> #4892
> > >> > >> banana plugs and Belden #9272 wire. Why 9272, because it was
> handy
> > >> at the
> > >> > >> time. It is tin plated copper, shielded twisted pair 20 ga. I
> have
> > >> plans
> > >> > >> to do custom cables with 16 ga. bare copper wire that I will
> twist
> > >> and
> > >> > >> then
> > >> > >> put a braided shield over it. I simply cannot find what I want
> so I
> > >> will
> > >> > >> build my own cable. I have done something like this before and
> it
> > >> worked
> > >> > >> fine. When I get a "round toit".
> > >> > >>
> > >> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads that
> I
> > >> have
> > >> > >> used
> > >> > >> in the past to verify my homemade "low thermal" leads as
> described
> > >> above.
> > >> > >> Frankly I cannot see any difference between using the 1756 cables
> > >> and my
> > >> > >> homemade cables once I give them a few minutes for the thermals
> to go
> > >> > >> away.
> > >> > >> As far as I can tell and measure the differences, if any, are
> below
> > >> 0.1
> > >> > >> ppm
> > >> > >> at 10 volts.
> > >> > >>
> > >> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on the
> 732A
> > >> are all
> > >> > >> adjustable you may be seeing a misadjusted 1 volt from the
> 732A. As
> > >> far
> > >> > >> as
> > >> > >> the instability of the readings it is hard to determine which is
> > >> causing
> > >> > >> the
> > >> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 with
> the
> > >> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this
> > >> does is
> > >> > >> set
> > >> > >> the MATH to "Statistics" (store high reading/low reading/ and
> mean
> > >> of the
> > >> > >> readings) in the registers, the number of readings to "40", the
> > >> trigger to
> > >> > >> "hold" (which keeps the meter from triggering until I press
> "ENTER"
> > >> and
> > >> > >> then
> > >> > >> trigger the sequence of 40 readings when I push the "ENTER"
> button.
> > >> You
> > >> > >> can
> > >> > >> do all of this manually from the keypads but since I use this
> > >> sequence a
> > >> > >> lot
> > >> > >> I have preprogrammed it. This is after I set digits to "8" and
> PLC
> > >> to
> > >> > >> 100.
> > >> > >> Once those 40 readings are finished then you can access the
> various
> > >> MATH
> > >> > >> statistic registers, using the menu, by entering "MATH" and then
> a 2
> > >> for
> > >> > >> low, a 4 for mean, and 13 for high. Of course you could do all
> of
> > >> this
> > >> > >> through the IEEE also. The 3458A has a very rich set of
> measurement
> > >> > >> commands. I am still learning all of them. It depends upon
> what I
> > >> am
> > >> > >> trying to accomplish.
> > >> > >>
> > >> > >> Since the 1.018 and 1.0 volt outputs are passive and derived
> from
> > >> > >> resistive dividers from the 10 volt, I don't see how they could
> > >> contribute
> > >> > >> to the varying readings you are measuring. I think I would put a
> > >> short on
> > >> > >> the input of the 3458A and manually set the range to 1 volt and
> then
> > >> > >> observe
> > >> > >> the variations that way without the 732A involved. When I do
> this I
> > >> see a
> > >> > >> variation from low reading to high reading of 0.125 uVolts and
> then
> > >> > >> another
> > >> > >> 40 I get 0.155 uVolts. This is without the GUARD connected to
> the
> > >> low
> > >> > >> side
> > >> > >> of the measurment terminals, GUARD connected doesn't seem to
> affect
> > >> the
> > >> > >> readings. So that is the base noise of the 3458A without the
> 732A,
> > >> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 volt
> > >> output I
> > >> > >> got
> > >> > >> a variation of 0.159 uVolts using the same 40 reading method
> above.
> > >> I
> > >> > >> would
> > >> > >> use this to determine where your problem might exist. Just
> having
> > >> the
> > >> > >> meter
> > >> > >> input shorted will point you in the right direction. Meter,
> cables
> > >> or
> > >> > >> 732A.
> > >> > >>
> > >> > >> Sorry for the long dissertation. Friends get mad at me for
> > >> being so
> > >> > >> detailed sometimes.
> > >> > >>
> > >> > >> Bill
> > >> > >>
> > >> > >> ----- Original Message -----
> > >> > >> From: "Randy Evans" <randyevans2688@gmail.com>
> > >> > >> To: "Discussion of precise voltage measurement" <
> volt-nuts@febo.com>
> > >> > >> Sent: Sunday, August 24, 2014 7:22 AM
> > >> > >> Subject: Re: [volt-nuts] 732A and Prologix received
> > >> > >>
> > >> > >>
> > >> > >> > Bill,
> > >> > >> >
> > >> > >> > I have convinced myself that the problem I an seeing is due to
> > >> thermals.
> > >> > >> > If I move the cables (with gold-plated banana plugs) using a
> small
> > >> > >> towel
> > >> > >> > rather than letting my hand touch the plugs, it is much more
> > >> stable.
> > >> > >> If I
> > >> > >> > then hold the banana plug with my hand after the reading has
> > >> stabilized,
> > >> > >> > the reading drifts rapidly upward. I am trying to check the
> > >> stability
> > >> > >> of
> > >> > >> > the reading but I haven't figured out the MATH function yet. I
> > >> assume
> > >> > >> this
> > >> > >> > is a programmed function using GPIB only?
> > >> > >> >
> > >> > >> > The stability I am seeing by manually recording readings (using
> > >> NLPC of
> > >> > >> 100
> > >> > >> > and 1000) is much greater than what you are measuring on your
> > >> system.
> > >> > >> Not
> > >> > >> > sure how to ascertain if it's the 3458A or the 732. The value
> of
> > >> the
> > >> > >> > readings are very different between the two - the 3458 reads
> about
> > >> 50 uV
> > >> > >> > high on the 10 V output and about 12 uV low on the 1V output.
> > >> Rather
> > >> > >> large
> > >> > >> > differences (this is after an ACAL). I need to find some
> better
> > >> cables
> > >> > >> to
> > >> > >> > make sure the errors are not due to thermals again.
> > >> > >> >
> > >> > >> > Randy
> > >> > >> >
> > >> > >> >
> > >> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold <
> wpgold3637@att.net>
> > >> wrote:
> > >> > >> >
> > >> > >> > > Randy:
> > >> > >> > >
> > >> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and they
> > >> will fit
> > >> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic
> > >> LC-R064R5C and
> > >> > >> > > others
> > >> > >> > > that are in this size and package. Order from one of the
> usual
> > >> > >> electronics
> > >> > >> > > distributors like Allied, Mouser, Digikey. This is a very
> common
> > >> > >> battery
> > >> > >> > > as
> > >> > >> > > it is used in a lot of "EXIT" signs so they are lighted when
> the
> > >> power
> > >> > >> goes
> > >> > >> > > out. I don't see how the 12V 7AH will fit as they are too
> > >> large. I
> > >> > >> guess
> > >> > >> > > you could use a 12V 5AH (PS1250) as it is the same size as 2
> x 6
> > >> volt
> > >> > >> 4
> > >> > >> AH
> > >> > >> > > but the terminals are in the wrong place so you will have to
> > >> "nibble"
> > >> > >> out
> > >> > >> > > the aluminum plate that holds them in the 732A battery pack.
> > >> You have
> > >> > >> to
> > >> > >> > > be
> > >> > >> > > careful if you use the 12v 5AH as you will have 4 extra
> battery
> > >> > >> connection
> > >> > >> > > leads to deal with and connect correctly. I would stick with
> > >> the 6V
> > >> > >> 4AH.
> > >> > >> > > New batteries will last around 12 to 14 hours before the
> "CAL"
> > >> light
> > >> > >> goes
> > >> > >> > > out when AC power is not applied. So shipping to Cal Lab
> can be
> > >> a
> > >> > >> problem
> > >> > >> > > if it is a distance away, or you have to use a shipper like
> UPS
> > >> or
> > >> > >> FEDEX
> > >> > >> > > and
> > >> > >> > > you ship the night before and then use their "Morning
> delivery"
> > >> and
> > >> > >> the
> > >> > >> Cal
> > >> > >> > > Lab is expecting your 732A. Same on the way back to you. Of
> > >> course
> > >> > >> you
> > >> > >> > > could always strap another battery on the 732A and hook it
> up to
> > >> the
> > >> > >> "ext
> > >> > >> > > power" plug to last longer. I have seen it done. The issue
> is
> > >> to get
> > >> > >> the
> > >> > >> > > Cal Lab to charge the extra battery before they ship the 732A
> > >> back to
> > >> > >> you.
> > >> > >> > >
> > >> > >> > > When you remove and work on the battery pack always have
> the
> > >> AC
> > >> > >> power
> > >> > >> > > plugged in. The "CAL" led will stay on because the 18.6 v
> > >> regulated
> > >> > >> supply
> > >> > >> > > is working.
> > >> > >> > >
> > >> > >> > > The "CAL" light is to indicate that power has not been
> lost
> > >> to the
> > >> > >> > > Reference Amp or other associated circuits. When the raw
> supply
> > >> > >> (battery)
> > >> > >> > > voltage drops below about 21 volts the "CAL" light will go
> out.
> > >> Below
> > >> > >> that
> > >> > >> > > voltage the heater circuits will not work correctly and the
> 18.6
> > >> volt
> > >> > >> > > regulated supply will not regulate. The requirement is that
> the
> > >> > >> Reference
> > >> > >> > > Amp be kept "alive" at all times to maintain the output
> voltage
> > >> that
> > >> > >> was
> > >> > >> > > measured at the time of the most recent Calibration or
> > >> Certification.
> > >> > >> When
> > >> > >> > > the semiconductor junctions are unbiased and cool off when
> power
> > >> is
> > >> > >> lost,
> > >> > >> > > and then power is restored the result will be a different 10
> > >> volts
> > >> > >> than
> > >> > >> > > before the power failure. My experience is that after all
> of the
> > >> > >> years
> > >> > >> > > that
> > >> > >> > > these units have been powered up, this won't happen and when
> > >> power is
> > >> > >> lost
> > >> > >> > > and then restored, even months later, the 732A will come
> back to
> > >> > >> almost
> > >> > >> > > exactly the same 10 volts as when they lost power, usually
> with
> > >> in 0.2
> > >> > >> PPM
> > >> > >> > > after 24 hours of "warm up".
> > >> > >> > >
> > >> > >> > > What type of hookup leads are you using when measuring
> the 1
> > >> volt
> > >> > >> > > output? What is the PLC set to? I always use 100 PLC to
> measure
> > >> > >> this.
> > >> > >> If
> > >> > >> > > you don't have "low thermal" connection leads you can
> experience
> > >> uV
> > >> > >> changes
> > >> > >> > > for a minute or more after plugging in the leads due to the
> > >> "thermals"
> > >> > >> > > generated because of the difference in temperature between
> the
> > >> banana
> > >> > >> jacks
> > >> > >> > > on the 732A and the banana plugs of the leads. I have found
> > >> that even
> > >> > >> just
> > >> > >> > > plugging in the lead will generate a thermal difference
> because
> > >> of
> > >> > >> > > difference of temps and some heating due to the physical act
> of
> > >> just
> > >> > >> > > inserting the plug because of friction between the jack and
> plug
> > >> (my
> > >> > >> theory
> > >> > >> > > at any rate). You have to allow at least a minute or more
> before
> > >> > >> being
> > >> > >> > > able
> > >> > >> > > to make a measurement after plugging in the leads. I just
> > >> measured
> > >> > >> the
> > >> > >> > > variation of the 1 volt output of my 732A and using my 3458A
> and
> > >> I
> > >> > >> got a
> > >> > >> > > total difference of 0.159 uV over 40 measurements using 100
> PLC
> > >> on
> > >> > >> the
> > >> > >> 1
> > >> > >> > > volt range of the 3458A. Using the MATH function and all of
> the
> > >> data
> > >> > >> you
> > >> > >> > > can collect. That was after waiting for several minutes
> after
> > >> > >> plugging
> > >> > >> in
> > >> > >> > > the leads.
> > >> > >> > >
> > >> > >> > > I hope all of this helps.
> > >> > >> > >
> > >> > >> > > Bill
> > >> > >> > >
> > >> > >> > >
> > >> > >> > >
> > >> > >> > > ----- Original Message -----
> > >> > >> > > From: "Randy Evans" <randyevans2688@gmail.com>
> > >> > >> > > To: "Discussion of precise voltage measurement" <
> > >> volt-nuts@febo.com>
> > >> > >> > > Sent: Friday, August 22, 2014 9:03 PM
> > >> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received
> > >> > >> > >
> > >> > >> > >
> > >> > >> > > > Todd,
> > >> > >> > > >
> > >> > >> > > > Thanks for the info. I have several Panasonic 12V 7 AH
> > >> batteries
> > >> > >> that
> > >> > >> I
> > >> > >> > > > keep topped off and they have very low current draw (~2 to
> 3
> > >> mA at
> > >> > >> 13.5
> > >> > >> > > > VDC) when charged and at their float voltage, so I am
> pretty
> > >> sure
> > >> > >> they
> > >> > >> > > are
> > >> > >> > > > in good condition. I will look at getting those in the
> units
> > >> after
> > >> > >> I
> > >> > >> > > > ascertain the condition of the 732.
> > >> > >> > > >
> > >> > >> > > > So now I have a what appears to be a functioning 3458A and
> a
> > >> 732A
> > >> > >> but
> > >> > >> > > they
> > >> > >> > > > slightly disagree. I am like the man with two watches that
> > >> disagree
> > >> > >> on
> > >> > >> > > the
> > >> > >> > > > time - which is correct? For the moment, i am only
> concerned
> > >> with
> > >> > >> > > > stability. The need for absolute accuracy will come later.
> > >> > >> > > >
> > >> > >> > > > Randy
> > >> > >> > > >
> > >> > >> > > >
> > >> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef <
> > >> tmicallef@gmail.com
> > >> > >> >
> > >> > >> > > wrote:
> > >> > >> > > >
> > >> > >> > > > > Randy,
> > >> > >> > > > >
> > >> > >> > > > > You have two possible choices. It can be configured with
> 4 x
> > >> 6v
> > >> > >> 4Ah
> > >> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the
> previous
> > >> owner
> > >> > >> has
> > >> > >> > > > > modified the battery pack already. A couple of mine
> needed a
> > >> > >> nibbler
> > >> > >> > > tool
> > >> > >> > > > > to remove enough of the aluminum cover that fits over the
> > >> tops of
> > >> > >> the
> > >> > >> > > > > batteries. The original cover will short out to the
> battery
> > >> tabs
> > >> > >> > > regardless
> > >> > >> > > > > of the battery configuration if this is not done.
> > >> > >> > > > >
> > >> > >> > > > > You can find larger capacity batteries that will give you
> > >> slightly
> > >> > >> more
> > >> > >> > > > > battery life. I lost a couple sets of mail-order
> batteries
> > >> after a
> > >> > >> few
> > >> > >> > > > > extended outages. I would recommend going with locally
> bought
> > >> > >> batteries
> > >> > >> > > > > instead of the cheaper mail order. My local Batteries
> Plus
> > >> will
> > >> > >> > > typically
> > >> > >> > > > > have some warranty if I remember correctly. Moving
> forward I
> > >> will
> > >> > >> only
> > >> > >> > > use
> > >> > >> > > > > 2 12v batteries and pre-charge them on a battery charger
> to
> > >> > >> equalize
> > >> > >> > > them
> > >> > >> > > > > before putting them in the 732A. I think the cheap
> batteries
> > >> did
> > >> > >> not
> > >> > >> > > > > discharge equally, and would not recover when power was
> > >> applied.
> > >> > >> > > > >
> > >> > >> > > > > Inspect the back plane for damaged traces and look at the
> > >> > >> capacitors. I
> > >> > >> > > had
> > >> > >> > > > > a few that looked questionable. So far, I have replaced
> all
> > >> the
> > >> > >> big
> > >> > >> > > caps
> > >> > >> > > on
> > >> > >> > > > > the pre-regulator and regulator boards. My feeling is
> that
> > >> once
> > >> > >> these
> > >> > >> > > go
> > >> > >> > > > > online, they should run as long as possible between
> repairs.
> > >> > >> > > > >
> > >> > >> > > > > The battery charger circuit may need adjusting. I tweaked
> > >> mine and
> > >> > >> it
> > >> > >> > > > > seemed to work fine.
> > >> > >> > > > >
> > >> > >> > > > > Todd
> > >> > >> > > > >
> > >> > >> > > > >
> > >> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans <
> > >> > >> > > randyevans2688@gmail.com>
> > >> > >> > > > > wrote:
> > >> > >> > > > >
> > >> > >> > > > > > I received my Fluke 732A today. Just powered it up
> but it
> > >> needs
> > >> > >> new
> > >> > >> > > > > > batteries. Any suggestions for sources (I haven't
> opened
> > >> up the
> > >> > >> unit
> > >> > >> > > > > yet -
> > >> > >> > > > > > I want to make sure it works before doing that). Also
> > >> received
> > >> > >> the
> > >> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims'
> CAL
> > >> ran
> > >> > >> data
> > >> > >> > > > > dumper
> > >> > >> > > > > > program to get the CAL data from my 3458A. Should be a
> > >> busy
> > >> > >> weekend.
> > >> > >> > > > > >
> > >> > >> > > > > > Randy
> > >> > >> > > > > > _______________________________________________
> > >> > >> > > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > > > To unsubscribe, go to
> > >> > >> > > > > >
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > > > and follow the instructions there.
> > >> > >> > > > > >
> > >> > >> > > > > _______________________________________________
> > >> > >> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > > To unsubscribe, go to
> > >> > >> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > > and follow the instructions there.
> > >> > >> > > > >
> > >> > >> > > > _______________________________________________
> > >> > >> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > >> > >> > > > To unsubscribe, go to
> > >> > >> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > >> > >> > > > and follow the instructions there.
> > >> > >> > >
> > >> > >> > > _______________________________________________
> > >> > >> > > volt-nuts mailing list -- volt-nuts@febo.com
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> > >> > >> > >
> > >> > >> > _______________________________________________
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> > >> > >>
> > >> > >> _______________________________________________
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> > >> > >>
> > >> > >
> > >> > >
> > >> > _______________________________________________
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> > >
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