[volt-nuts] Reference Calibration Options - Solartron7081andFluke 731B and 335A

[gbusg]

Fred wrote:

>How do you know the standards drift and not the meters?

Josephson Array

>Yesterday i turned on the 7061 again and it showed 1.000,006,2 V after
>three hours it was 1.000,000,1 V and stayed there, so keeping it powered on
>seems to work better.

Yes, effectively you were characterizing the warm-up characteristics of your
7061. Obviously don't depend on it for the best accuracy and stability right 
after
power-up.

> have last week adjusted to 1.000,000 V on the keithley 2000.
>After a week it was 1.000,046 but I adjusted it to 1 V  again. But the
>reference in that has only about 150 hours burn in time total. The Short
>time drift is now allmost gone. It flips + 1 uV now and then, but it could
>be it is adjusted to 1.000,000,8 or so.

Yeah, I would definitely leave your Keithley 2000 running 24/7 for the
foreseeable future, while you're running these kinds of experiments.

Keep up the good work and experimenting, Fred!

-Greg