Calibration of 34401A
I have a 'friend" (actually a person who I have never met, but is a pain in
the ***).
He sold a Agilent 34401A multimeter which the customer said is out of
specification and can not be adjusted.
Quickly scanning the measurent results, the meter is not showing results
with any huge errors (say 1%), but which (if any) range it is out of
specification I don't know. Unlike the Keysight calibration certificates I
have seen, the measurement results doesn't show the upper and lower limits
for the specification of the meter, so one can not tell from a quick
glance if the meter is out of specification. One would need to study the
detailed specification.
IF I understand correctly, (and the data is in Spanish which I don't
speak), with an input of 9,99990 V, the meter reads 9,99899 which the
data indicates is an error of -91 uV/V with an uncertainty of 7.7 uV/V.
The lab said the meter can not be adjusted. I don't know if they mean
- This lab has no ability to adjust the meter.
OR
- It is too far off to adjust.
Does anybody know if a 34401A can be adjusted by a competent 3rd party lab,
or are the details of how to adjust the meter not available outside of
Keysight?
Dave
Calibration of a 34401A is done electronically, however one needs to know the calibration security code.If unknown one needs to open the meter to enable calibration and then reassemble it and complete the calibration. The factory default calibration security code is HP034401 only 034401 need be entered from the front panel.Details are given in the service manual. Everything can be done from the front panel or over the HPIB.
A ~90ppm error shouldn't be a calibration issue as the initial calibration has to cope with the manufacturing tolerance for the LM399 internal reference.
For the 10V range the calibration source needs to be accurately known and within the [9, 11]Volt range.It also needs to be reversed to allow linearity calibration.
Bruce
On Wednesday, 12 October 2016 9:54 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@kirkbymicrowave.co.uk> wrote:
I have a 'friend" (actually a person who I have never met, but is a pain in
the ***).
He sold a Agilent 34401A multimeter which the customer said is out of
specification and can not be adjusted.
Quickly scanning the measurent results, the meter is not showing results
with any huge errors (say 1%), but which (if any) range it is out of
specification I don't know. Unlike the Keysight calibration certificates I
have seen, the measurement results doesn't show the upper and lower limits
for the specification of the meter, so one can not tell from a quick
glance if the meter is out of specification. One would need to study the
detailed specification.
IF I understand correctly, (and the data is in Spanish which I don't
speak), with an input of 9,99990 V, the meter reads 9,99899 which the
data indicates is an error of -91 uV/V with an uncertainty of 7..7 uV/V.
The lab said the meter can not be adjusted. I don't know if they mean
- This lab has no ability to adjust the meter.
OR
- It is too far off to adjust.
Does anybody know if a 34401A can be adjusted by a competent 3rd party lab,
or are the details of how to adjust the meter not available outside of
Keysight?
Dave
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In message 120112818.2234439.1476263954443@mail.yahoo.com, Bruce Griffiths wr
ites:
Does anybody know if a 34401A can be adjusted by a competent 3rd party lab,
or are the details of how to adjust the meter not available outside of
Keysight?
The service manual has the calibration procedure, and it is all software.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On Wed, Oct 12, 2016 at 09:54:01AM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
He sold a Agilent 34401A multimeter which the customer said is out of
specification and can not be adjusted.
Quickly scanning the measurent results, the meter is not showing results
with any huge errors (say 1%), but which (if any) range it is out of
specification I don't know. Unlike the Keysight calibration certificates I
have seen, the measurement results doesn't show the upper and lower limits
for the specification of the meter, so one can not tell from a quick
glance if the meter is out of specification. One would need to study the
detailed specification.
In the service guide (document 34401-90013) you will find the full list of
performance verification tests with upper and lower limits. You will need a
calibrator to verify them (except zero).
The DC 10V range accepted error after 1 year from calibration is +- 400uV
(+-190uV after 24 hours, +-250uV after 90 days), so -910uV are
in effect not inside limits and the instrument needs calibration.
Best regards,
Andrea Baldoni
On 12 Oct 2016 10:31, "Poul-Henning Kamp" phk@phk.freebsd.dk wrote:
Griffiths wr
ites:
Does anybody know if a 34401A can be adjusted by a competent 3rd party
lab,
or are the details of how to adjust the meter not available outside of
Keysight?
The service manual has the calibration procedure, and it is all software.
--
Poul-Henning Kamp |
Cheers. It seems that the lab is incompetent then, as none of the values
appeared to be in a massive difference
I had fixed 34401A before and DIY calibrate using on-hand sources, with
calibrated 7.5d DMM as reference.
Whole process can be visible on video -
https://www.youtube.com/watch?v=9kukXTqhzsU if you like.
So it's not a rocket science, but does need set of stable
sources/calibrator.
12/10/16 17:53, Dr. David Kirkby (Kirkby Microwave Ltd) пишет:
On 12 Oct 2016 10:31, "Poul-Henning Kamp" phk@phk.freebsd.dk wrote:
Griffiths wr
ites:
Does anybody know if a 34401A can be adjusted by a competent 3rd party
lab,
or are the details of how to adjust the meter not available outside of
Keysight?
The service manual has the calibration procedure, and it is all software.
--
Poul-Henning Kamp |
Cheers. It seems that the lab is incompetent then, as none of the values
appeared to be in a massive difference
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and follow the instructions there.
The only problem could be that the current calibration is already using
most of the adjustment range making the required adjustment outside the
limits.
On Wed, Oct 12, 2016 at 4:32 AM, Illya Tsemenko illya@xdevs.com wrote:
I had fixed 34401A before and DIY calibrate using on-hand sources, with
calibrated 7.5d DMM as reference.
Whole process can be visible on video - https://www.youtube.com/watch?
v=9kukXTqhzsU if you like.
So it's not a rocket science, but does need set of stable
sources/calibrator.
12/10/16 17:53, Dr. David Kirkby (Kirkby Microwave Ltd) пишет:
On 12 Oct 2016 10:31, "Poul-Henning Kamp" phk@phk.freebsd.dk wrote:
Griffiths wr
ites:
Does anybody know if a 34401A can be adjusted by a competent 3rd party
lab,
or are the details of how to adjust the meter not available outside of
Keysight?
The service manual has the calibration procedure, and it is all software.
--
Poul-Henning Kamp |
Cheers. It seems that the lab is incompetent then, as none of the values
appeared to be in a massive difference
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ailman/listinfo/volt-nuts
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John Phillips