[volt-nuts] traceable calibration

[Andreas Jahn]

Ok Greg,

so for the 10V range the specs seem to be totally identical.
But since they have a 90 day calibration cycle for the 5720A
according to the measurement protocol id prefer to use the
90 day spec which is 2.5ppm of output + 2.5uV for the 2 sigma
or 3ppm of output + 3uV for the 3 sigma value.

The interesting thing is that on a sample report
acoording to ISO they state the measurement uncertainity of being
16.1 uV for a 5V output and
28.1 uV for a 10V output.

http://www.keithley.com/support/services/calibrationrepair/ReportA.pdf

On the other side on their calibration side they say that they will use
the 2 sigma specs for ISO-calibration.
  5V would give   15  uV with 2 sigma
10V would give 27.5 uV with 2 sigma.

so the values of the protocol seem to include a tolerance 0.6 to 1.1 uV for 
wiring.

so I would use the calibrator tolerance as being 2.5ppm + 3.6uV as worst 
case
and transfer this to the 7V of my reference voltage as 21.1uV uncertainity 
for the calibrator.
But how do I have to regard the other tolerances up to the measurement of my
LM399 #2?

With best regards

Andreas

----- Original Message ----- 
From: "gbusg" <gbusg at comcast.net>
To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
Sent: Saturday, September 10, 2011 7:24 AM
Subject: Re: [volt-nuts] traceable calibration


> Andreas asked:
>
>>So the specs I got from the Fluke homepage. I did not find
>>calibrator specs for the non Series II device.
>>I hope that this does not make a too big difference.
>>Do you have the standard 5720A specs?
>
> ----------------
>
> Hi Andreas,
>
> I compared the Fluke 5720A 2-sigma specs to their 5720A *Series II* 
> 2-sigma
> specs, and on the 11Vdc range, they both have identical specs. For example
> they're both spec'd as +/- (3.5ppm output + 2.5 uV) for 1 Year.
>
> Cheers,
> Greg
>
>
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