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" <[email protected]> > An: [email protected] > Betreff: Re: [volt-nuts] Advise to Junior Member Regarding Acquisition of > Fluke 5XXX Series Calibrator > > [email protected] 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 > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
