[volt-nuts] Reference Calibration Options - Solartron 7081andFluke 731B and 335A

[gbusg]

Charles wrote:

>... the actual expected stability of a properly operating
>731B (particularly one that has been operating 24/7 for several years
>or more) is significantly better than the specified performance of a
>7081 (or 3458A), and in addition its drift can be characterized
>reasonably accurately and subtracted (not so much with meters, with
>their several different error mechanisms).

Hi Charles - I'll trade you a 731B for your 732A! :-)

The beauty of the 3458A is that the drift/aging of its DC circuitry 
(everything except its LTZ-1000 Reference) can
effectively be cancelled anytime the user invokes its "ACAL DC" feature. In 
other words, immediately after each "ACAL DC", the meter's DC aging is 
solely a function of the aging/drift of its 7V Zener Reference. This feature 
plus the meter's state-of-art linearity give you a meter whose actual low DC 
error is difficult to characterize unless you have a *trended* 732A 
(trending based on its history as measured via a Josephson Array).

Cheers,
Greg