BG
Bill Gold
Sun, Aug 24, 2014 11:46 PM
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
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. 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
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
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 4
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 FEDEX
and
you ship the night before and then use their "Morning delivery" and the
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
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 was
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 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
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
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.
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 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
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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
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 they
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
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 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
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 equalize
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
a few that looked questionable. So far, I have replaced all the big
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.
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.
TM
Todd Micallef
Sun, Aug 24, 2014 11:52 PM
Bill,
Thanks for the tip. Do you have an automated measurement system for the
10v inter-comparisons or do you manually log them with a spreadsheet?
I don't think the 12v are better, but it is interesting that some people
have modified them to dual batteries. I do not think there is any added
benefit unless someone happens to use a lot of those particular 12v
batteries.
So far I have two with the 6v packs and one with the 12v. I have a
fourth one waiting to be repaired once I finish my current projects.
Todd
Sent from my iPad
Todd:
I check the batteries every month per the 732A manual. Usually I keep
few used cells from previous packs around that seem to be ok after
them for capacity just like checking the battery pack. I can usually spot
cells going bad with that method. If I don't have a spare set then I just
substitute a used cell until I receive a new set.
I agree with you that the cheap ones are crap. I have used Power Sonic
a lot with some a few EaglePicher and one set of Enersys. The EaglePicher
are crap so I will never use them. EaglePicher have had a couple out of 8
that have failed very early. I have never tried Panasonic. So I stick
the Power Sonic's. I am not sure why the 12 volt ones would be better
the 6 volts because 12 volt is just 6 lead acid cells while the 6volt are
lead acid cells. If one of the 6 cells in the 12 volt battery go bad then
the whole battery has to be changed. So you better buy good quality 12
batteries.
I just can't seem to source batteries locally easily at a reasonable
price. So I order them from Allied usually.
Bill
----- Original Message -----
From: "Todd Micallef" <tmicallef@gmail.com javascript:;>
To: "Discussion of precise voltage measurement" <volt-nuts@febo.com
Sent: Sunday, August 24, 2014 8:13 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I use a lot of the 12v 7ah batteries for my UPS backups and 732B. But
I was mistaken. The 12V 5ah batteries are the ones that I am using in one
of my 732A. There is more play inside the tray with the 12v batteries by
several mm as compared to the 6v which only has a 2-3mm. The 12v
is not difficult, but it is easier if the battery tray has already been
machined for the 12v batteries. The battery tabs don't line up well with
the existing holes and need to be widened. Two additional holes must also
be added.
Sourcing the batteries locally is more of a convenience than waiting for
the delivery. The el-cheapo 6v batteries are a waste of money and I have
batteries so far to prove it. They died the first time I had a 6hr outage
and would not hold a charge after that.
Todd
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 4
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 FEDEX
and
you ship the night before and then use their "Morning delivery" and the
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
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 was
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 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
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
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.
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 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
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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
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 they
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
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
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
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 equalize
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
a few that looked questionable. So far, I have replaced all the big
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.
and follow the instructions there.
Bill,
Thanks for the tip. Do you have an automated measurement system for the
10v inter-comparisons or do you manually log them with a spreadsheet?
I don't think the 12v are better, but it is interesting that some people
have modified them to dual batteries. I do not think there is any added
benefit unless someone happens to use a lot of those particular 12v
batteries.
So far I have two with the 6v packs and one with the 12v. I have a
fourth one waiting to be repaired once I finish my current projects.
Todd
Sent from my iPad
> On Aug 24, 2014, at 17:44, "Bill Gold" <wpgold3637@att.net <javascript:;>>
wrote:
>
> Todd:
>
> I check the batteries every month per the 732A manual. Usually I keep
a
> few used cells from previous packs around that seem to be ok after
checking
> them for capacity just like checking the battery pack. I can usually spot
> cells going bad with that method. If I don't have a spare set then I just
> substitute a used cell until I receive a new set.
>
> I agree with you that the cheap ones are crap. I have used Power Sonic
> a lot with some a few EaglePicher and one set of Enersys. The EaglePicher
> are crap so I will never use them. EaglePicher have had a couple out of 8
> that have failed very early. I have never tried Panasonic. So I stick
with
> the Power Sonic's. I am not sure why the 12 volt ones would be better
than
> the 6 volts because 12 volt is just 6 lead acid cells while the 6volt are
3
> lead acid cells. If one of the 6 cells in the 12 volt battery go bad then
> the whole battery has to be changed. So you better buy good quality 12
volt
> batteries.
>
> I just can't seem to source batteries locally easily at a reasonable
> price. So I order them from Allied usually.
>
> Bill
>
> ----- Original Message -----
> From: "Todd Micallef" <tmicallef@gmail.com <javascript:;>>
> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com
<javascript:;>>
> Sent: Sunday, August 24, 2014 8:13 AM
> Subject: Re: [volt-nuts] 732A and Prologix received
>
>
>> Bill,
>>
>> I use a lot of the 12v 7ah batteries for my UPS backups and 732B. But
yes,
>> I was mistaken. The 12V 5ah batteries are the ones that I am using in one
>> of my 732A. There is more play inside the tray with the 12v batteries by
>> several mm as compared to the 6v which only has a 2-3mm. The 12v
> conversion
>> is not difficult, but it is easier if the battery tray has already been
>> machined for the 12v batteries. The battery tabs don't line up well with
>> the existing holes and need to be widened. Two additional holes must also
>> be added.
>>
>> Sourcing the batteries locally is more of a convenience than waiting for
>> the delivery. The el-cheapo 6v batteries are a waste of money and I have
8
>> batteries so far to prove it. They died the first time I had a 6hr outage
>> and would not hold a charge after that.
>>
>> Todd
>>
>>
>>
>>
>>> On Sat, Aug 23, 2014 at 1:21 PM, Bill Gold <wpgold3637@att.net
<javascript:;>> 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 <javascript:;>>
>>> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com
<javascript:;>>
>>> 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
<javascript:;>>
>>>> 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 <javascript:;>>
>>>>> 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 <javascript:;>
>>>>>> 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 <javascript:;>
>>>>> 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 <javascript:;>
>>>> 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 <javascript:;>
>>> 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 <javascript:;>
>> 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 <javascript:;>
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
RE
Randy Evans
Mon, Aug 25, 2014 12:01 AM
Bill,
Thanks for the MATH overview. That could be very helpful. I definately
will give it a try.
Randy
On Sun, Aug 24, 2014 at 2:44 PM, Bill Gold wpgold3637@att.net wrote:
Todd:
I check the batteries every month per the 732A manual. Usually I keep
a
few used cells from previous packs around that seem to be ok after checking
them for capacity just like checking the battery pack. I can usually spot
cells going bad with that method. If I don't have a spare set then I just
substitute a used cell until I receive a new set.
I agree with you that the cheap ones are crap. I have used Power Sonic
a lot with some a few EaglePicher and one set of Enersys. The EaglePicher
are crap so I will never use them. EaglePicher have had a couple out of 8
that have failed very early. I have never tried Panasonic. So I stick
with
the Power Sonic's. I am not sure why the 12 volt ones would be better than
the 6 volts because 12 volt is just 6 lead acid cells while the 6volt are 3
lead acid cells. If one of the 6 cells in the 12 volt battery go bad then
the whole battery has to be changed. So you better buy good quality 12
volt
batteries.
I just can't seem to source batteries locally easily at a reasonable
price. So I order them from Allied usually.
Bill
----- Original Message -----
From: "Todd Micallef" tmicallef@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 8:13 AM
Subject: Re: [volt-nuts] 732A and Prologix received
Bill,
I use a lot of the 12v 7ah batteries for my UPS backups and 732B. But
I was mistaken. The 12V 5ah batteries are the ones that I am using in one
of my 732A. There is more play inside the tray with the 12v batteries by
several mm as compared to the 6v which only has a 2-3mm. The 12v
is not difficult, but it is easier if the battery tray has already been
machined for the 12v batteries. The battery tabs don't line up well with
the existing holes and need to be widened. Two additional holes must also
be added.
Sourcing the batteries locally is more of a convenience than waiting for
the delivery. The el-cheapo 6v batteries are a waste of money and I have
batteries so far to prove it. They died the first time I had a 6hr outage
and would not hold a charge after that.
Todd
On Sat, Aug 23, 2014 at 1:21 PM, 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 4
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 the
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 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
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
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.
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 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
total difference of 0.159 uV over 40 measurements using 100 PLC on the
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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 I
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a 732A but
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 4Ah
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 big
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.
Bill,
Thanks for the MATH overview. That could be very helpful. I definately
will give it a try.
Randy
On Sun, Aug 24, 2014 at 2:44 PM, Bill Gold <wpgold3637@att.net> wrote:
> Todd:
>
> I check the batteries every month per the 732A manual. Usually I keep
> a
> few used cells from previous packs around that seem to be ok after checking
> them for capacity just like checking the battery pack. I can usually spot
> cells going bad with that method. If I don't have a spare set then I just
> substitute a used cell until I receive a new set.
>
> I agree with you that the cheap ones are crap. I have used Power Sonic
> a lot with some a few EaglePicher and one set of Enersys. The EaglePicher
> are crap so I will never use them. EaglePicher have had a couple out of 8
> that have failed very early. I have never tried Panasonic. So I stick
> with
> the Power Sonic's. I am not sure why the 12 volt ones would be better than
> the 6 volts because 12 volt is just 6 lead acid cells while the 6volt are 3
> lead acid cells. If one of the 6 cells in the 12 volt battery go bad then
> the whole battery has to be changed. So you better buy good quality 12
> volt
> batteries.
>
> I just can't seem to source batteries locally easily at a reasonable
> price. So I order them from Allied usually.
>
> Bill
>
> ----- Original Message -----
> From: "Todd Micallef" <tmicallef@gmail.com>
> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Sent: Sunday, August 24, 2014 8:13 AM
> Subject: Re: [volt-nuts] 732A and Prologix received
>
>
> > Bill,
> >
> > I use a lot of the 12v 7ah batteries for my UPS backups and 732B. But
> yes,
> > I was mistaken. The 12V 5ah batteries are the ones that I am using in one
> > of my 732A. There is more play inside the tray with the 12v batteries by
> > several mm as compared to the 6v which only has a 2-3mm. The 12v
> conversion
> > is not difficult, but it is easier if the battery tray has already been
> > machined for the 12v batteries. The battery tabs don't line up well with
> > the existing holes and need to be widened. Two additional holes must also
> > be added.
> >
> > Sourcing the batteries locally is more of a convenience than waiting for
> > the delivery. The el-cheapo 6v batteries are a waste of money and I have
> 8
> > batteries so far to prove it. They died the first time I had a 6hr outage
> > and would not hold a charge after that.
> >
> > Todd
> >
> >
> >
> >
> > On Sat, Aug 23, 2014 at 1:21 PM, 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.
>
RE
Randy Evans
Mon, Aug 25, 2014 12:31 AM
Bill,
I am trying to figure out the MATH function without much success. The 3458
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
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
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 4
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 the
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 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
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
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.
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 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
total difference of 0.159 uV over 40 measurements using 100 PLC on the
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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 I
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a 732A but
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 4Ah
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 big
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.
Bill,
I am trying to figure out the MATH function without much success. The 3458
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.
>
RE
Randy Evans
Mon, Aug 25, 2014 1:04 AM
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
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
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 4
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 the
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 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
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
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.
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 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
total difference of 0.159 uV over 40 measurements using 100 PLC on the
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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 I
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a 732A but
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 4Ah
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 big
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.
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.
>
CB
Charles Black
Mon, Aug 25, 2014 2:18 AM
Hi Randy,
You can use the NPLC command to change the A/D converter's'integration
time. Set it to 1000 if you want full resolution. It sets the hp3458a's NMR.
Charlie
On 8/24/2014 6:04 PM, Randy Evans 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
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
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 4
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 the
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 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
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
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.
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 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
total difference of 0.159 uV over 40 measurements using 100 PLC on the
volt range of the 3458A. Using the MATH function and all of the data
can collect. That was after waiting for several minutes after plugging
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 I
ascertain the condition of the 732.
So now I have a what appears to be a functioning 3458A and a 732A but
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 4Ah
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 big
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,
You can use the NPLC command to change the A/D converter's'integration
time. Set it to 1000 if you want full resolution. It sets the hp3458a's NMR.
Charlie
On 8/24/2014 6:04 PM, Randy Evans 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.
>
>
>
OE
Orin Eman
Mon, Aug 25, 2014 4:33 AM
Randy & all,
You have correctly concluded that some (maybe not all) of your measurement
problem is thermal EMF being added or subtracted in series within your
measurement interconnect. This thermal EMF is generated at the junction of
dissimilar metals when accompanied with thermal gradients between the test
lead and device terminals. You have to eliminate both the dissimilarity of
the metal junctions as well as minimize the thermal differences. The
terminals of the 3458A as well as the 732A are Beryllium Copper so you want
to use the same test lead terminals. Forget the typical Tin plated lugs or
even Gold plated as both are not Beryllium Copper and constitute dissimilar
metals. The best solution (as usually the most expensive) is to use a set
of
Fluke 5440A-7005 (48") cables. I also have just as good results using the
much more flexible Pomona 11174A (lugs end always stay connected to the
732A) or 11058A with more convenient shielded banana plugs. The Fluke cable
has the added Guard built in but be sure to also use a Guard lead with the
Pomona cabled. The Guard lead does not need to be low thermal EMF. DIY
cables is usually not a good idea because the lead wire to terminal also
constitutes just as critical of junction. The above cables use Tellurium
Copper wire which is usually hard to find and hard to crimp properly and
NEVER solder.
11058A and 11174A are discontinued at Keysight. However, Pomona 5295 spade
to banana cables are available (5295-36 at Mouser et al) and claim that
they are designed to minimize thermal EMFs. Datasheet is here:
http://www.mouser.com/ds/2/159/d5295_1_01-51722.pdf Any comments on these
as an alternative?
Orin.
On Sun, Aug 24, 2014 at 1:46 PM, Don@True-Cal <truecalservices@gmail.com>
wrote:
> Randy & all,
>
> You have correctly concluded that some (maybe not all) of your measurement
> problem is thermal EMF being added or subtracted in series within your
> measurement interconnect. This thermal EMF is generated at the junction of
> dissimilar metals when accompanied with thermal gradients between the test
> lead and device terminals. You have to eliminate both the dissimilarity of
> the metal junctions as well as minimize the thermal differences. The
> terminals of the 3458A as well as the 732A are Beryllium Copper so you want
> to use the same test lead terminals. Forget the typical Tin plated lugs or
> even Gold plated as both are not Beryllium Copper and constitute dissimilar
> metals. The best solution (as usually the most expensive) is to use a set
> of
> Fluke 5440A-7005 (48") cables. I also have just as good results using the
> much more flexible Pomona 11174A (lugs end always stay connected to the
> 732A) or 11058A with more convenient shielded banana plugs. The Fluke cable
> has the added Guard built in but be sure to also use a Guard lead with the
> Pomona cabled. The Guard lead does not need to be low thermal EMF. DIY
> cables is usually not a good idea because the lead wire to terminal also
> constitutes just as critical of junction. The above cables use Tellurium
> Copper wire which is usually hard to find and hard to crimp properly and
> NEVER solder.
>
11058A and 11174A are discontinued at Keysight. However, Pomona 5295 spade
to banana cables are available (5295-36 at Mouser et al) and claim that
they are designed to minimize thermal EMFs. Datasheet is here:
http://www.mouser.com/ds/2/159/d5295_1_01-51722.pdf Any comments on these
as an alternative?
Orin.
A
acbern@gmx.de
Mon, Aug 25, 2014 10:36 AM
I have used the pomona spades, mainly to interface the low emf pomona banana cables to binding posts. I have stopped this, reasons being, they are large and worse, that the pomona spring loaded insulation tube that covers the banana plug conductor uses such a strong spring that slowly the plug works its way out of the spade. this btw also happend to me when I used the pomona low emf binding posts together with the pomona low emf banana cables. overall I m not happy with these.
so, due to lack of options, I changed to self-made twisted shielded pair of high grade teflon/kapton silver plated copper cable with gold plated copper spades (crimped). I use them not only with the 3458a but also with nanovolt meters. these have higher resolution and accuracy in low level measurements than the 3458a. emf voltages were never an issue with these cables if properly used. I have posted some results doing 34420a stabilty measurements on the pmel forum, and the results are convincing (purpose was actually not to test the cables but the stability of the 34420a, but the emf issue is a part of this of course. we use the 34420a to do low voltage precision measurements on thermal converters where the full scale signal sometimes is 1mV).
that btw also relates to don's statements below, I do not concurr with his comments about copper telurium as cable and spade material and so on. this material, as stated here many times, is used because it is machinable, for copper spades one would not use it. the 34420a factory cable uses copper cable and copper spades, not telurium-copper. if there was a problem, it would be worse with the 34420a than with the 3458a because of its low level ranges. and again, I have not seen any problems in a chain of (output to input):
1.copper-tellurium post from e.g. 8 digit calibrator
2.crimped copper spade, gold plated
3.silver plated tsp copper cable
4a.crimped copper spade to copper-tellurium post or
4b.soldered copper connector(34420)
my consistent results over more than a year using them.
Randy & all,
You have correctly concluded that some (maybe not all) of your measurement
problem is thermal EMF being added or subtracted in series within your
measurement interconnect. This thermal EMF is generated at the junction of
dissimilar metals when accompanied with thermal gradients between the test
lead and device terminals. You have to eliminate both the dissimilarity of
the metal junctions as well as minimize the thermal differences. The
terminals of the 3458A as well as the 732A are Beryllium Copper so you want
to use the same test lead terminals. Forget the typical Tin plated lugs or
even Gold plated as both are not Beryllium Copper and constitute dissimilar
metals. The best solution (as usually the most expensive) is to use a set
of
Fluke 5440A-7005 (48") cables. I also have just as good results using the
much more flexible Pomona 11174A (lugs end always stay connected to the
732A) or 11058A with more convenient shielded banana plugs. The Fluke cable
has the added Guard built in but be sure to also use a Guard lead with the
Pomona cabled. The Guard lead does not need to be low thermal EMF. DIY
cables is usually not a good idea because the lead wire to terminal also
constitutes just as critical of junction. The above cables use Tellurium
Copper wire which is usually hard to find and hard to crimp properly and
NEVER solder.
I have used the pomona spades, mainly to interface the low emf pomona banana cables to binding posts. I have stopped this, reasons being, they are large and worse, that the pomona spring loaded insulation tube that covers the banana plug conductor uses such a strong spring that slowly the plug works its way out of the spade. this btw also happend to me when I used the pomona low emf binding posts together with the pomona low emf banana cables. overall I m not happy with these.
so, due to lack of options, I changed to self-made twisted shielded pair of high grade teflon/kapton silver plated copper cable with gold plated copper spades (crimped). I use them not only with the 3458a but also with nanovolt meters. these have higher resolution and accuracy in low level measurements than the 3458a. emf voltages were never an issue with these cables if properly used. I have posted some results doing 34420a stabilty measurements on the pmel forum, and the results are convincing (purpose was actually not to test the cables but the stability of the 34420a, but the emf issue is a part of this of course. we use the 34420a to do low voltage precision measurements on thermal converters where the full scale signal sometimes is 1mV).
that btw also relates to don's statements below, I do not concurr with his comments about copper telurium as cable and spade material and so on. this material, as stated here many times, is used because it is machinable, for copper spades one would not use it. the 34420a factory cable uses copper cable and copper spades, not telurium-copper. if there was a problem, it would be worse with the 34420a than with the 3458a because of its low level ranges. and again, I have not seen any problems in a chain of (output to input):
1.copper-tellurium post from e.g. 8 digit calibrator
2.crimped copper spade, gold plated
3.silver plated tsp copper cable
4a.crimped copper spade to copper-tellurium post or
4b.soldered copper connector(34420)
my consistent results over more than a year using them.
> Gesendet: Montag, 25. August 2014 um 06:33 Uhr
> Von: "Orin Eman" <orin.eman@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] 732A and Prologix received
>
> On Sun, Aug 24, 2014 at 1:46 PM, Don@True-Cal <truecalservices@gmail.com>
> wrote:
>
> > Randy & all,
> >
> > You have correctly concluded that some (maybe not all) of your measurement
> > problem is thermal EMF being added or subtracted in series within your
> > measurement interconnect. This thermal EMF is generated at the junction of
> > dissimilar metals when accompanied with thermal gradients between the test
> > lead and device terminals. You have to eliminate both the dissimilarity of
> > the metal junctions as well as minimize the thermal differences. The
> > terminals of the 3458A as well as the 732A are Beryllium Copper so you want
> > to use the same test lead terminals. Forget the typical Tin plated lugs or
> > even Gold plated as both are not Beryllium Copper and constitute dissimilar
> > metals. The best solution (as usually the most expensive) is to use a set
> > of
> > Fluke 5440A-7005 (48") cables. I also have just as good results using the
> > much more flexible Pomona 11174A (lugs end always stay connected to the
> > 732A) or 11058A with more convenient shielded banana plugs. The Fluke cable
> > has the added Guard built in but be sure to also use a Guard lead with the
> > Pomona cabled. The Guard lead does not need to be low thermal EMF. DIY
> > cables is usually not a good idea because the lead wire to terminal also
> > constitutes just as critical of junction. The above cables use Tellurium
> > Copper wire which is usually hard to find and hard to crimp properly and
> > NEVER solder.
> >
>
>
> 11058A and 11174A are discontinued at Keysight. However, Pomona 5295 spade
> to banana cables are available (5295-36 at Mouser et al) and claim that
> they are designed to minimize thermal EMFs. Datasheet is here:
> http://www.mouser.com/ds/2/159/d5295_1_01-51722.pdf Any comments on these
> as an alternative?
>
> Orin.
> _______________________________________________
> 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.
BG
Bill Gold
Mon, Aug 25, 2014 1:40 PM
Randy:
Sorry my fault. You have to use the "RMATH" command to get the various
values stored in the registers. See the "RMATH" command in the User's Guide
for a list of what registers you can read.
I sure haven't found any other guides other than the 4 manuals. User's
Guide, Quick Reference Guide, Calibration Manual, and Assembly Level Repair.
It is just a matter of reading the guides and trying to remember what
commands are available. It took me a lot of time to figure out what
commands I use now. I am sure I am missing other commands that might be
useful.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 6:04 PM
Subject: Re: [volt-nuts] 732A and Prologix received
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;
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
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
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
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
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 have
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 my
homemade cables once I give them a few minutes for the thermals to go
As far as I can tell and measure the differences, if any, are below 0.1
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A are
adjustable you may be seeing a misadjusted 1 volt from the 732A. As far
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
readings) in the registers, the number of readings to "40", the trigger
"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
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
to the varying readings you are measuring. I think I would put a short
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
variation from low reading to high reading of 0.125 uVolts and then
40 I get 0.155 uVolts. This is without the GUARD connected to the low
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
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
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 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
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
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
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 large. I
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 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
Cal Lab to charge the extra battery before they ship the 732A back
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
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 that
measured at the time of the most recent Calibration or
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
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
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 uV
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 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
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
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
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 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
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
battery life. I lost a couple sets of mail-order batteries after
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
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
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 up
I want to make sure it works before doing that). Also
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.
and follow the instructions there.
Randy:
Sorry my fault. You have to use the "RMATH" command to get the various
values stored in the registers. See the "RMATH" command in the User's Guide
for a list of what registers you can read.
I sure haven't found any other guides other than the 4 manuals. User's
Guide, Quick Reference Guide, Calibration Manual, and Assembly Level Repair.
It is just a matter of reading the guides and trying to remember what
commands are available. It took me a lot of time to figure out what
commands I use now. I am sure I am missing other commands that might be
useful.
Bill
----- Original Message -----
From: "Randy Evans" <randyevans2688@gmail.com>
To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
Sent: Sunday, August 24, 2014 6:04 PM
Subject: Re: [volt-nuts] 732A and Prologix received
> 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.
P
pa4tim@gmail.com
Mon, Aug 25, 2014 1:43 PM
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
Verzonden met Windows Mail
Van: Bill Gold
Verzonden: maandag 25 augustus 2014 15:40
Aan: volt-nuts
Randy:
Sorry my fault. You have to use the "RMATH" command to get the various
values stored in the registers. See the "RMATH" command in the User's Guide
for a list of what registers you can read.
I sure haven't found any other guides other than the 4 manuals. User's
Guide, Quick Reference Guide, Calibration Manual, and Assembly Level Repair.
It is just a matter of reading the guides and trying to remember what
commands are available. It took me a lot of time to figure out what
commands I use now. I am sure I am missing other commands that might be
useful.
Bill
----- Original Message -----
From: "Randy Evans" randyevans2688@gmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Sunday, August 24, 2014 6:04 PM
Subject: Re: [volt-nuts] 732A and Prologix received
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;
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
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
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
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
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 have
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 my
homemade cables once I give them a few minutes for the thermals to go
As far as I can tell and measure the differences, if any, are below 0.1
at 10 volts.
Since the 10 volt, 1.0 volt and 1.018 volt outputs on the 732A are
adjustable you may be seeing a misadjusted 1 volt from the 732A. As far
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
readings) in the registers, the number of readings to "40", the trigger
"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
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
to the varying readings you are measuring. I think I would put a short
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
variation from low reading to high reading of 0.125 uVolts and then
40 I get 0.155 uVolts. This is without the GUARD connected to the low
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
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
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 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
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
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
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 large. I
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 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
Cal Lab to charge the extra battery before they ship the 732A back
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
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 that
measured at the time of the most recent Calibration or
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
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
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 uV
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 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
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
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
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 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
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
battery life. I lost a couple sets of mail-order batteries after
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
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
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 up
I want to make sure it works before doing that). Also
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.
and follow the instructions there.
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
Verzonden met Windows Mail
Van: Bill Gold
Verzonden: maandag 25 augustus 2014 15:40
Aan: volt-nuts
Randy:
Sorry my fault. You have to use the "RMATH" command to get the various
values stored in the registers. See the "RMATH" command in the User's Guide
for a list of what registers you can read.
I sure haven't found any other guides other than the 4 manuals. User's
Guide, Quick Reference Guide, Calibration Manual, and Assembly Level Repair.
It is just a matter of reading the guides and trying to remember what
commands are available. It took me a lot of time to figure out what
commands I use now. I am sure I am missing other commands that might be
useful.
Bill
----- Original Message -----
From: "Randy Evans" <randyevans2688@gmail.com>
To: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
Sent: Sunday, August 24, 2014 6:04 PM
Subject: Re: [volt-nuts] 732A and Prologix received
> 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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> > > > > To unsubscribe, go to
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> > > > > and follow the instructions there.
> > > >
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