Re: Accurate voltage calibration

Leon wrote:
Alfred Green wrote:

I have recently aquired a nice 5.1/2 digit DVM, and would like to assess
the absolute accuracy. Many years ago I had a 'Standard Cell', but that
got lost in one of my several relocations.


I don't think there is an easy to do what you want, otherwise people
wouldn't spend lots of money getting their standards calibrated at
national standards labs like NPL. Your best bet might be to find
someone who has access to a regularly calibrated DVM and check it
against that, or send it away to get it calibrated.


Well, maybe askimg for 1e-5 was very optimistic, but I would like to see what can be done in a home environment.
For ham use I couldn't justify getting it professionally calibrated, but I'll check with the test-equipment guy at work to see if we have something recently done that I can do a comparison from.

Standard voltage diodes are available and are used as secondary
standards, but are probably quite expensive and difficult to find.


That was kind of what I was looking for. I really am prepared to pay a few bob for something that I can reliably use as a reference in my lab.

You should have kept your Weston cell. 8-) BTW, NPL even offers a
calibration service for them, the volt is defined using a Josephson
junction, these days.


Oh yep. I think it was amongst the stuff that got lost in the move from UK to the States back in '85. They do show up on Ebay occaisionally, but I'd like to think there was something newer that could do the job.
Interesting to hear about the current Volt definition: I'll do some searching for some more info on that.

Thanks for your comments,

73 Alf NU8I (aka G4ABB, amongst others)
.

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