[volt-nuts] Advise to Junior Member Regarding Acquisition of Fluke 5XXX Series Calibrator

[acbern at gmx.de]

Hi John,

sure, seems I should have been more clear. What I wanted to say is that in order to have traceability starting from just a calibrated 10V (and 10k) standard, which is sufficient to adjust a 3458A, you still need some type of self-calibrating divider to validate the 3458A (which then, once validated, can be your working unit). Or, if one e.g. wants to calibrate a 5440 voltage calibrator from a 10V standard, you also need a divider. Assuming a non-calibrated 3458A, because of its highly linear ADC, can be used transferring the 10V into other voltage ranges, is not valid, the 3458A has a performance validation point that checks (within the testable limits) that the linearity is ok. So no way around a divider unfortunately. 
In the end, what we talk about is how do we get traceable volts measurement capabilities (to the 10V standard that has been calibrated, if one has a calibrated 1V too (of the 732A or whatever), less work, but the basic problem remains).

Adrian



> Gesendet: Freitag, 24. April 2015 um 11:43 Uhr
> Von: "John Devereux" <john at devereux.me.uk>
> An: volt-nuts at febo.com
> Betreff: Re: [volt-nuts] Advise to Junior Member Regarding Acquisition of Fluke	5XXX Series Calibrator
>
> acbern at gmx.de writes:
> 
> > A few things to keep in mind:
> > - the 720A (and the 752A) are self-calibrating, i.e. you can (easily)
> > calibrate it yourself before use. The 3458A, using its external
> > artifact self-cal procedure based on only 10v and 10k, requires a
> > performance verification therafter (at least every second time, see
> > some military docs concluding this, I don't recall the link but easy
> > to find; i would actually say, to comply with GUM, every time).
> 
> Hi Adrian
> 
> I don't think that this point is a fair comparison, 3458a calibration is
> only required for absolute measurements which the 720A is incapable of
> anyway.
> 
> John
>