[volt-nuts] A Fluke 732A: Return it or keep it?

[wb6bnq]

Hi Michael,

I agree with Orin, you do not have the ability, on hand, to verify the 
732A.  If you have the manual, try seeing if the Acceptance procedure 
(page 4-8) gives reasonable results.

Are there any stickers that indicate what the thermister value should be 
?  Keep in mind that it is a value that is reported with each 
calibration session.

If you have a calibration facility near you, it would pay to have them 
take a comparison between your 10 volt value and their local reference.  
Of course this is assuming that they have something comparable in quality.

The battery should be the least of your worries, as the instrument does 
run off of the AC line and provides charging to the battery.

The last thing you want to do is fiddle with the calibration pots !

As you have no calibration history on the unit, you have no way of 
knowing its true voltage value.  The bottom line is you would have to 
send it to a proper calibration facility to have any reasonable 
assurance of valid values.  From then on it is a matter of keeping 
records and tracking its operation to really know its behavior and to 
what level it can be trusted in the long term.

Agin, keep the screwdrivers out of it !


Bill....WB6BNQ



Orin Eman wrote:

>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 at 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
>>_______________________________________________
>>volt-nuts mailing list -- volt-nuts at 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 at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
>and follow the instructions there.
>
>  
>