Calibration Sources for Solartron 7081
I recently added another Solartron 7081 to my collection that seems to be
working correctly, is stable and I have upgraded it to the latest firmware.
However, it is clearly not accurate, at least on the 10 VDC scale, measuring
my 10.000 000 standard at about 10.000 840 V while my other meters are +/-
about 10 uV of 10.000 000 VDC.
If I understand the calibration procedure correctly, I will need an input
short, an input open, and 'standards' for each of the VDC, VAC, and Ohms
ranges to perform a complete calibration procedure. This would appear to be
a source for 0.1, 1, 10, 100, and 1000 VDC and VAC along with 0.1, 1, 10,
100, and 1000 kOhm and 10 and 1000 MOhm resistor standards. I can come up
with the VDC standards and the resistance standards except the 1000 MOhm. I
don't have 'standards' but I have references that are stable and calibrated
meters (another 7081 and two 3458A's) that I can use to measure my
references and then input their measurements into the DUT 7081 to perform
the calibrations.
My questions are:
What source could/should I use for the ACV and what frequency for the ACV?
I can come up with a power transformer and a variac for 60 Hz. I also have
a selection of signal generators and synthesizers for amplitudes up to about
+10 dBm at pretty much any frequency you prefer.
What would be the lowest ACV that I could/should use for the 1000 VAC scale?
What suggestions for the 1000 MOhm standard? What is the lowest value that
I could/should use for the 1000 MOhm scale?
My plan is to test each scale against my other meters and calibrate only the
scales that are 'out of bounds'. Good idea or bad?
Thanks in advance.
Joe
Hi J. L.
From: "J. L. Trantham" jltran@att.net
What source could/should I use for the ACV and what frequency for the ACV?
I can come up with a power transformer and a variac for 60 Hz.
The stability is not high enough to be useful!
Have a look to http://www.on4jln.be/infos/getfile?file=515A-OM.pdf,
it is the Fluke 515A, to learn how they dealt with that problem. If your 10V
is good you will get better results too. And it needs to be very good to calibrate
the 7081! Stability is more important than everything else and that is the problem.
Have a good day.
Bye,
Jean-Louis
Jean-Louis,
My DC standards are a Fluke 731B and Fluke 335A DC Voltage Standards and an
EDC CR103 DC Current and Voltage Standard.
My resistance standards consist of a collection of Leeds and Northrup type
standard resistors as well as a collection of General Radio Decade
Resistance boxes that will get me up into the MegOhm range.
However, AC promises to be a problem. I guess I will try using a signal
generator and an amplifier to see what output level and stability I can
achieve.
But still, what frequency? 60 Hz? 1 kHz?
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Jean-Louis Noel
Sent: Friday, June 22, 2012 3:58 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Calibration Sources for Solartron 7081
Hi J. L.
From: "J. L. Trantham" jltran@att.net
What source could/should I use for the ACV and what frequency for the
ACV? I can come up with a power transformer and a variac for 60 Hz.
The stability is not high enough to be useful!
Have a look to http://www.on4jln.be/infos/getfile?file=515A-OM.pdf,
it is the Fluke 515A, to learn how they dealt with that problem. If your 10V
is good you will get better results too. And it needs to be very good to
calibrate the 7081! Stability is more important than everything else and
that is the problem.
Have a good day.
Bye,
Jean-Louis
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
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Hi J. L.
From: "J. L. Trantham" jltran@att.net
However, AC promises to be a problem. I guess I will try using a signal
generator and an amplifier to see what output level and stability I can
achieve.
You have to link the amplifier to your DC standard to have the stability needed.
But still, what frequency? 60 Hz? 1 kHz?
The 'basic' calibration is usually performed at 400Hz.
With check at higher frequencies (40KHz and 400KHz for the 7081) to know if it's still properly compensated.
Bye,
Jean-Louis
I made it through the DC Cal steps this evening and I was reading about the
Ohms calibration.
What resistance standards are needed? 10000 ohms and 1000 ohms? 4 wire or
2?
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Jean-Louis Noel
Sent: Friday, June 22, 2012 9:25 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Calibration Sources for Solartron 7081
Hi J. L.
From: "J. L. Trantham" jltran@att.net
However, AC promises to be a problem. I guess I will try using a
signal generator and an amplifier to see what output level and
stability I can achieve.
You have to link the amplifier to your DC standard to have the stability
needed.
But still, what frequency? 60 Hz? 1 kHz?
The 'basic' calibration is usually performed at 400Hz.
With check at higher frequencies (40KHz and 400KHz for the 7081) to know if
it's still properly compensated.
Bye,
Jean-Louis
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.