A Fluke 732A: Return it or keep it?
Hi nuts,
This is my first message. Just reading the posted messages is a big learning to me so I didn't post but instead trying to read all.
Here is my issue.
I received a Fluke 732A yesterday which was purchased from an eBay seller.
(1)
I plugged in and started measuring the 3 voltages and thermistor resistance value.
After about 2 hours later all 3 voltages were stabilized and thermistor value stabilized after 24 hours.
All voltages and thermistor values were measured on a HP 3457 which was calibrated and certified by a local cal lab 10 months ago. Here is how I measure: After changing the connection to a different voltage I wait 30 second. I start STAT and wait 1 minute and R MEAN.
10V (10.000360 36.0ppm, 360uV)
1V (1.0000383 38.3ppm, 38.3uV)
1.018V (1.0180200 20ppm, 20uV)
According to the manual adjustable(calibration) ranges are:
10V 5ppm 50uV
1V 5ppm 5uV
1.018 50ppm 50uV
So obviously either 732A or 3457A is wrong.
I tried to contact the person who calibrated the HP 3457A. No response.
(2)
No light on BTRY CHG and IN CAL
Rear panel Battery Operation switch is on.
(3)
Front panel calibration hole
I put a thin flat blade driver into the holes. I couldn't feel anything until 4 1/4" inside where I felt something but not the potentiometer.
I offered to the seller that if I find the 732A is no problem but only requires the new battery, refunding $150 for the battery will close the deal. All other case, I return the item.
He responded "Just return it."
My questions:
(1) Which one is wrong the DMM or 732A?
(2) What is the cheapest battery replacement cost?
(3) Were the calibration mechanism removed or they are there? In manual I couldn't find any detailed description or diagram of it.
Last, I paid $650 plus $35 shipping. Do you think it is worth without battery, if voltages are in the range?
Michael
Best I can tell, the 3457A 1 year spec is 0.0040% of reading + 19 counts
for 6.5 digits on the 30V scale, 100PLC, cal temp +/- 5 deg C.
Your 10.00036 V reading is therefore +/- 0.00059 V. I'd say you can't
really tell with the 3457A whether the 732A is close or not.
Orin.
On Fri, Mar 7, 2014 at 4:19 PM, Michael Hong mikeyahee@yahoo.com wrote:
Hi nuts,
This is my first message. Just reading the posted messages is a big
learning to me so I didn't post but instead trying to read all.
Here is my issue.
I received a Fluke 732A yesterday which was purchased from an eBay seller.
(1)
I plugged in and started measuring the 3 voltages and thermistor
resistance value.
After about 2 hours later all 3 voltages were stabilized and thermistor
value stabilized after 24 hours.
All voltages and thermistor values were measured on a HP 3457 which was
calibrated and certified by a local cal lab 10 months ago. Here is how I
measure: After changing the connection to a different voltage I wait 30
second. I start STAT and wait 1 minute and R MEAN.
10V (10.000360 36.0ppm, 360uV)
1V (1.0000383 38.3ppm, 38.3uV)
1.018V (1.0180200 20ppm, 20uV)
According to the manual adjustable(calibration) ranges are:
10V 5ppm 50uV
1V 5ppm 5uV
1.018 50ppm 50uV
So obviously either 732A or 3457A is wrong.
I tried to contact the person who calibrated the HP 3457A. No response.
(2)
No light on BTRY CHG and IN CAL
Rear panel Battery Operation switch is on.
(3)
Front panel calibration hole
I put a thin flat blade driver into the holes. I couldn't feel anything
until 4 1/4" inside where I felt something but not the potentiometer.
I offered to the seller that if I find the 732A is no problem but only
requires the new battery, refunding $150 for the battery will close the
deal. All other case, I return the item.
He responded "Just return it."
My questions:
(1) Which one is wrong the DMM or 732A?
(2) What is the cheapest battery replacement cost?
(3) Were the calibration mechanism removed or they are there? In manual I
couldn't find any detailed description or diagram of it.
Last, I paid $650 plus $35 shipping. Do you think it is worth without
battery, if voltages are in the range?
Michael
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Michael,
I would recommend you download the manual if you have not already done so.
(Sorry, just noticed you had looked at the manual.)
I don't think you are going to have enough resolution with the 3457A to
characterize the 732A, other than a rough idea of stability. You will need
a 3458A, a Solartron 7081 or some other 8 1/2 digit DMM.
The unit uses four 6 V SLA batteries that are relatively cheap. I ordered 8
of them since shipping was the same, whether I got 4 or 8. Unless they were
recently replaced, you will need to replace them. The 'In Cal' light needs
to be 'reset' after the unit is powered up, stabilized, and calibrated. It
remains on as long as there is continuous power applied to the unit, either
from AC, the battery pack, or an external battery attached to the connector
on the back. I have a spare connector, yours for cost plus shipping, if you
need one. Two others on the list have sent me the money for one but work
has really interfered with my life this week and I have not yet shipped
them. It will be tomorrow. (Sorry, guys, my apologies.)
The batteries I ordered are these:
http://www.batteryclerk.com/store/p/80492-Panasonic-LC-RB064P-Sealed-Lead-Ac
id-AGM-VRLA-Battery.html $5.69 each plus shipping.
If power is lost, power must be re-attached and the 'In Cal' light 'reset'.
The light is 'reset' by connecting the negative terminal to a spot in the
'reset' hole just below the 'In Cal' light.
If the battery charge light is not on, and the unit is plugged in, the
batteries are either completely charged, not connected, dead, or there is a
problem with the charger circuit. My bet is a battery issue since I bet you
had to plug in the unit to get it to work.
There is a multi-turn pot inside each of the three holes and they are
difficult to get to but can be seen if you have a flashlight to shine in
essentially parallel to your line of sight. If the 10 V can't be brought to
exactly 10.0000000 V, there are 'jumpers' under the top layer of insulation
for the 'heated unit' that can be adjusted to bring it 'in range'. At least
I was able to bring mine 'in range' and 'calibrated' against my Agilent
Cal'd 3458A. Mine has been on continuously now for about 2 months. I
'calibrated' it after it was on for about a week. It now reads about
9.9999920 V and seems extremely stable (3458A with NDIG=8 and NPLC=60). I'm
thinking of 're-calibrating' it and see how close it will stay to 10.0000000
VDC. I think it will be more stable the longer it is on. I have no idea of
how long it was off before I turned it on.
The schematic of the A5 Reference PCB Assembly shows the calibration
adjustments and the drawing of that assembly shows the location of the
adjustments. They are deep inside the unit. You'll need a small flat
bladed tool, a flashlight, and probably a magnifier. I used a length of 12
ga. copper wire with one end flattened to make a screwdriver.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Michael Hong
Sent: Friday, March 07, 2014 6:19 PM
To: volt-nuts@febo.com
Subject: [volt-nuts] A Fluke 732A: Return it or keep it?
Hi nuts,
This is my first message. Just reading the posted messages is a big learning
to me so I didn't post but instead trying to read all.
Here is my issue.
I received a Fluke 732A yesterday which was purchased from an eBay seller.
(1)
I plugged in and started measuring the 3 voltages and thermistor resistance
value.
After about 2 hours later all 3 voltages were stabilized and thermistor
value stabilized after 24 hours.
All voltages and thermistor values were measured on a HP 3457 which was
calibrated and certified by a local cal lab 10 months ago. Here is how I
measure: After changing the connection to a different voltage I wait 30
second. I start STAT and wait 1 minute and R MEAN.
10V (10.000360 36.0ppm, 360uV)
1V (1.0000383 38.3ppm, 38.3uV)
1.018V (1.0180200 20ppm, 20uV)
According to the manual adjustable(calibration) ranges are:
10V 5ppm 50uV
1V 5ppm 5uV
1.018 50ppm 50uV
So obviously either 732A or 3457A is wrong.
I tried to contact the person who calibrated the HP 3457A. No response.
(2)
No light on BTRY CHG and IN CAL
Rear panel Battery Operation switch is on.
(3)
Front panel calibration hole
I put a thin flat blade driver into the holes. I couldn't feel anything
until 4 1/4" inside where I felt something but not the potentiometer.
I offered to the seller that if I find the 732A is no problem but only
requires the new battery, refunding $150 for the battery will close the
deal. All other case, I return the item.
He responded "Just return it."
My questions:
(1) Which one is wrong the DMM or 732A?
(2) What is the cheapest battery replacement cost?
(3) Were the calibration mechanism removed or they are there? In manual I
couldn't find any detailed description or diagram of it.
Last, I paid $650 plus $35 shipping. Do you think it is worth without
battery, if voltages are in the range?
Michael
volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to
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and follow the instructions there.
Michael,
I would start with what is the easiest to test. If you look inside the "Reset"
hole and do not see a bare metal contact behind the hole, there is missing
hardware. I can look inside one of mine and I can see it with no problem.
You only need a short piece of stripped wire to touch between the contact
and a grounded binding post. My concern would be is if anything is missing.
The LEDs are on the same board. Do you have a AC PWR LED lit?
So far, I have had three different 732A's that had the 10V outside of the
specified adjustable range. This is not unusual as many components have
aged. Fluke has the A7 board to compensate for this drift. It is not
absolutely imperative that it be adjusted to exactly 10V, but it does matter
if the unit meets its drift and noise specs.
I have had to repair the oven controller, replace all batteries, calibrate
the battery charging voltages, and replace the 10V pot inside two of the
reference ovens. Many different factors can affect the output voltages.
I believe the battery charge light only comes on when it is not trickle
charging. If you remove the AC power, will the 732A continue to operate?
Also, silly question, is the battery switch set to the on position? I had to
ask. You should be able to measure the battery charging voltage from the
back of the pack.
Todd
Michael wrote:
I received a Fluke 732A yesterday which was purchased from an eBay seller.
* * *
(1) Which one is wrong the DMM or 732A?
As others have said, you have no way to tell with what you have. I
note that the seller's 34401A read the 10v output as 10.0004v, pretty
consistent with the 10.00036 your 3457A read. So it seems likely
that the 732A really is significantly farther off than the cal pot
will correct, and the internal jumpers will need to be changed.
(2) What is the cheapest battery replacement cost?
Fluke built the 732A with four, 6v, 4.5AH SLA batteries. For some
years now, when Fluke replaces the batteries, they use two, 12v, 5AH
SLA batteries for a modest increase in capacity. I believe the best
course is to follow Fluke's lead, and use two, 12v, 5AH batteries
when I replace them.
Also, I strongly advise against using the cheapest batteries you can
get. Those will invariably be very low quality batteries, which will
fail prematurely. There is a huge difference in quality from good
SLAs to poor ones. I have found that PowerSonic SLA batteries give
good service in the 732A (about $35 each).
[NOTE: Be very careful shopping for SLA batteries -- the retail SLA
market is absolutely full of fraudulent marketing. For example,
http://www.batteryclerk.com/ does everything possible to make you
think you are buying genuine brand-name batteries, but all they sell
are "AJC" brand batteries, which are unmitigated crap. In tiny print
they say, "This is an AJC Brand replacement compatible with" and then
in giant red letters, "Panasonic (or other name brand) Sealed Lead
Acid Battery." Many, many vendors play this same game. Be
absolutely positive you're getting the real thing.]
In order for the 732A to do what it is supposed to do (be, without
question, the most accurate voltage standard you own), you will need
to send it to Fluke for calibration (or to one of the very, very few
other labs with sufficient accuracy and precision to calibrate a 0.1
ppm voltage standard). You will pay from $700 to $1500 for
this. Every year. So trying to save $50 on batteries is beyond foolish.
Last, I paid $650 plus $35 shipping. Do you think it is worth
without battery, if voltages are in the range?
It is hard to say what a fair price is. I have three, all of which
came from working calibration labs (so I know they had been back to
Fluke every year from new). Mine have never needed anything other
than batteries. The most expensive of the bunch cost me $325. But,
as noted above, the cost of the hardware is not the real expense --
it's those trips back to Fluke for calibration. (If you're not
willing to send it to Fluke for calibration, you're just wasting
money buying a 732A. You should get one of these instead):
http://www.voltagestandard.com/New_Products.html>
Best regards,
Charles
Charles,
Thanks for the info on batteries. I agree, some are definitely better than
others. However, I'm no 'connoisseur' of batteries yet. The 732A I got was
'unknown working condition' and I wanted the cheapest batteries I could find
to test the unit and see if I could get it up and running. So far, it looks
good.
Do you wind up having to re-solder some of the battery wires in the battery
module in order to use the 12 V 5 AH batteries or will they just swing to
the other side since it appears that the (+) and (-) terminals will wind up
on the same side, instead of opposite sides with the 6 V 4.5 AH batteries?
I have not faced the shipping question yet, but, as David pointed out, there
is an issue with shipping batteries. I suspect it could be shipped but
would be ground and, therefore, need a huge battery in order to get it to
the other side of the country 'hot'. I recall reading some thoughts on
current drain for the unit when on batteries but I do not remember what it
was. Clearly, it should be at a minimum, and therefore the battery should
last the longest, when already 'hot' when removed from AC power. Has anyone
done that experiment? I live in NW FL and I am not aware of Cal Labs in my
neighborhood that could do the work. Atlanta, perhaps? Does anyone have a
recommendation of a capable Cal facility 'close by' to NW FL?
Short of sending it to Fluke or another facility, I will be limited to using
my Agilent Cal'd 3458A to 'adjust' the 732A, then 'tracking' the 732A from
year to year as the 3458A comes back from Cal.
I paid less than Michael and more than you for my unit but it seems to work.
I have seen these sell on theBay for $450 and up.
Joe
In my humble opinion your are best off first checking for a local Cal Lab with a Josephson Junction Array Voltage Standard.
You can then drop it off and pick it up your 732A. I would imagine the day of abuse during shipping has more effect on uncertainty then the rest of the year combined sitting in a controlled lab environment. And Speaking of Lab environments adding precise temp and humidity control will have a substantial effect on 732A and 3458A stability. Hooking a number of small electric heaters to PID controllers can provide even out room temperature. Also I would almost always assume the 732A is more accurate then your 3458A even if you have the 002 or HFL option. Has anyone attempted changing the battery technology to Li-Ion and redesigning the charger? I am sure you could get greatly improved battery life.
Thomas Knox
From: jltran@att.net
To: volt-nuts@febo.com
Date: Sat, 8 Mar 2014 07:50:55 -0600
Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?
Charles,
Thanks for the info on batteries. I agree, some are definitely better than
others. However, I'm no 'connoisseur' of batteries yet. The 732A I got was
'unknown working condition' and I wanted the cheapest batteries I could find
to test the unit and see if I could get it up and running. So far, it looks
good.
Do you wind up having to re-solder some of the battery wires in the battery
module in order to use the 12 V 5 AH batteries or will they just swing to
the other side since it appears that the (+) and (-) terminals will wind up
on the same side, instead of opposite sides with the 6 V 4.5 AH batteries?
I have not faced the shipping question yet, but, as David pointed out, there
is an issue with shipping batteries. I suspect it could be shipped but
would be ground and, therefore, need a huge battery in order to get it to
the other side of the country 'hot'. I recall reading some thoughts on
current drain for the unit when on batteries but I do not remember what it
was. Clearly, it should be at a minimum, and therefore the battery should
last the longest, when already 'hot' when removed from AC power. Has anyone
done that experiment? I live in NW FL and I am not aware of Cal Labs in my
neighborhood that could do the work. Atlanta, perhaps? Does anyone have a
recommendation of a capable Cal facility 'close by' to NW FL?
Short of sending it to Fluke or another facility, I will be limited to using
my Agilent Cal'd 3458A to 'adjust' the 732A, then 'tracking' the 732A from
year to year as the 3458A comes back from Cal.
I paid less than Michael and more than you for my unit but it seems to work.
I have seen these sell on theBay for $450 and up.
Joe
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and follow the instructions there.
If you change to Li-Ion, you give up the ability to ship by air or at least
carry it in any passenger aircraft.
You might look at the Li-Ion motorcycle batteries. They are designed to
charge from a normal Pb-Ac system. Down side is a pair of them will run
~$600. They are >20 AH at 12 volts nominal.
Regards,
Tom
----- Original Message -----
From: "Tom Knox" actast@hotmail.com
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Saturday, March 08, 2014 10:42 AM
Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?
In my humble opinion your are best off first checking for a local Cal Lab
with a Josephson Junction Array Voltage Standard.
You can then drop it off and pick it up your 732A. I would imagine the day
of abuse during shipping has more effect on uncertainty then the rest of
the year combined sitting in a controlled lab environment. And Speaking of
Lab environments adding precise temp and humidity control will have a
substantial effect on 732A and 3458A stability. Hooking a number of small
electric heaters to PID controllers can provide even out room temperature.
Also I would almost always assume the 732A is more accurate then your
3458A even if you have the 002 or HFL option. Has anyone attempted
changing the battery technology to Li-Ion and redesigning the charger? I
am sure you could get greatly improved battery life.
Thomas Knox
From: jltran@att.net
To: volt-nuts@febo.com
Date: Sat, 8 Mar 2014 07:50:55 -0600
Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it?
Charles,
Thanks for the info on batteries. I agree, some are definitely better
than
others. However, I'm no 'connoisseur' of batteries yet. The 732A I got
was
'unknown working condition' and I wanted the cheapest batteries I could
find
to test the unit and see if I could get it up and running. So far, it
looks
good.
Do you wind up having to re-solder some of the battery wires in the
battery
module in order to use the 12 V 5 AH batteries or will they just swing to
the other side since it appears that the (+) and (-) terminals will wind
up
on the same side, instead of opposite sides with the 6 V 4.5 AH
batteries?
I have not faced the shipping question yet, but, as David pointed out,
there
is an issue with shipping batteries. I suspect it could be shipped but
would be ground and, therefore, need a huge battery in order to get it to
the other side of the country 'hot'. I recall reading some thoughts on
current drain for the unit when on batteries but I do not remember what
it
was. Clearly, it should be at a minimum, and therefore the battery
should
last the longest, when already 'hot' when removed from AC power. Has
anyone
done that experiment? I live in NW FL and I am not aware of Cal Labs in
my
neighborhood that could do the work. Atlanta, perhaps? Does anyone have
a
recommendation of a capable Cal facility 'close by' to NW FL?
Short of sending it to Fluke or another facility, I will be limited to
using
my Agilent Cal'd 3458A to 'adjust' the 732A, then 'tracking' the 732A
from
year to year as the 3458A comes back from Cal.
I paid less than Michael and more than you for my unit but it seems to
work.
I have seen these sell on theBay for $450 and up.
Joe
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Joe wrote:
Do you wind up having to re-solder some of the battery wires in the battery
module in order to use the 12 V 5 AH batteries or will they just swing to
the other side since it appears that the (+) and (-) terminals will wind up
on the same side, instead of opposite sides with the 6 V 4.5 AH batteries?
Sorry, I don't recall. Obviously, you need to remove some of the
wires since you only have 4 terminals. You also need to use a
nibbler to enlarge the holes for the terminals. All of that will be
instantly apparent when you have the batteries and the battery pack
in front of you. I've only converted one myself, which was not mine
-- all of mine have Fluke stickers on the back that say, "EXTENDED
BATTERY LIFE," which I believe is Fluke's way of indicating that they
did the conversion.
I have not faced the shipping question yet, but, as David pointed
out, there is an issue with shipping batteries.
I use FedEx overnight with "first thing" delivery and have not had
any problems. They slap some colorful stickers on the box and off it
goes. My external battery box is internally fused and has a
Hypertronics panel-mount connector identical to the one on the 732A,
so I use a cable with one of the Hypertronics plugs at each end to
connect them. I built a padded wooden shipping crate with separate
compartments for the 732A and the external battery pack and a channel
for the cable.
Speaking of the Hypertronics connectors, I expect to know more about
how to order them from Fluke in the weeks to come. You may recall I
asked a couple of weeks ago for confirmation that the panel-mount
connectors on all 732As have male pins (by "all" I mean all of the
newer ones with circular connectors for DC input, leaving aside the
older ones with 4mm banana jacks). They do, which means the plugs
need female contacts. This is backwards from the way these
connectors are traditionally assembled.
The part number I posted back on 12/30/13 is a current number, but it
is a part used by the BioMed division and is NOT the connector we
need -- the BioMed division assembles them the "traditional" way --
male contacts in the plug, and female contacts in the panel-mount connector.
All of this came to light after I gave that part number to a friend
and, like some others have reported, he received the plastic body
parts but no contacts. He called Fluke and eventually received the
contacts -- but they were male. After many e-mails and phone calls,
it became clear (i) that Fluke had a supply-chain problem that caused
the plastic bodies to be stocked and shipped without contacts, but
(ii) the contacts that were supposed to come with that part number
are the wrong gender for a 732A in any case. Fluke reports that the
supply chain problems are fixed, so the plugs under that part number
should now come with [male] contacts, but they have not yet created a
new part number for the plug that 732A owners need (plug body with
female contacts). When they do, Fluke will tell him, he will tell
me, and I will post the details.
All this was news to me, because my records show that the part number
I posted is the one I ordered 8 or 10 years ago, and at that time I
received plugs that work with the 732A. Puzzling. But in any case,
my friend says Fluke understands the issue and will fix it.
It took some effort, but in the end Fluke was very responsive to an
individual volt nut hobbyist looking for parts for an instrument that
went out of production in 1992 (I had no idea it was that long
ago). They deserve high praise for this, particularly when you
compare it to reports about support from other instrument makers.
Best regards,
Charles
Thomas wrote:
In my humble opinion your are best off first checking for a local
Cal Lab with a Josephson Junction Array Voltage Standard.
What you need is a cal lab that is accredited under the NIST NVLAP
program (or possibly by A2LA) and that has a DC source calibration
uncertainty certified to be 0.02 ppm or less, at least at 10v. The
Fluke cal lab meets this criterion, as do the Los Alamos and Sandia
standards labs (and, of course, NIST itself). Precious few others do.
A list of NVLAP-accredited labs can be found here:
http://ts.nist.gov/standards/scopes/dclow.htm
Certified uncertainties are found in each lab's current "Scope of
Accreditation" document.
Best regards,
Charles