[volt-nuts] AC calibration
cfharris at erols.com
Mon Aug 25 15:12:46 EDT 2014
Look up the phrase "AC thermal transfer standard".
Using a heater/thermocouple element in a vacuum is the tried
and true way of linking an AC voltage to a DC reference.
OBTW, trimming your quoted posts is considered friendly.
pa4tim at gmail.com wrote:
> Is there a way to link an AC voltage to a DC source for compare. I can check my
> calibrators (like a Fluke 332, 760 , 731 and a Philips) against standardcells.
> But for AC I can not do that. I have two AC+DC TRMS 7,5 digit meters but the last
> calibration was 2 years ago.
> My idea is in theory simple. It is based on the thermal converters used in RF
> powermeters. Two resistors, two high resolution temperature meters. AC on the
> first en DC on the second. If both are the same temperature the AC voltage is the
> same as the DC voltage. But I'm sure some people here have done this in the past.
> I would like to use it for 50 to 100 kHz (or less) and something like for 1V, 10V
> and 100V (and use several resistors/heaters.)
> Or mabey there is an other way to convert AC (for RF it can be done with lightbubs
> but I never tryed that) I do not mind if it is slow etc, I like this sort of
> experiments. You can learn a lot from it.
> Fred, pa4tim
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