[volt-nuts] 34401A Why 10M ohm default i/p resistance?

[Poul-Henning Kamp]

In message <53482D9E.9060904 at toneh.demon.co.uk>, Tony writes:

> I did find this explanation in the 3458A manual:
> 
> When making DC voltage measurements, you can fix the multimeter's input 
> resistance using the FlXEDZ command. This is useful to prevent a change 
> in input resistance caused by changing ranges) from affecting the 
> measurements.

Please don't forget that the 3458A is not just an 8.5 digit
metrological wonder, it is also a precision 16 bit 100 ksample/s
digitizer.

Many of the attributes of the input circuit are not there for
voltage metrology.

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