[Elecraft] Calibration Standard

[David A. Belsley]

A couple of general questions to the reflector regarding voltage meter 
calibration:

1) if the meter is spot-on on one scale, can one assume it is so on all 
scales (or all autoranges)?  I suspect the answer is no, but am surely 
willing to hear the word of those who know.

2) if the meter reads, say, 5.05 when it is measuring 5 volts, giving 
an absolute error of .05 volts and a relative error of 1%, is it the 
absolute error or relative error that is relevant.  That is, when 
measuring 100 actual volts, will one get 100.05 or 101 volts (modified, 
of course, by the issues entailed in question 1)?  I suspect the answer 
is "relative," but again, I would love to get the word from the 
experts.

thanks,

dave belsley, w1euy


On Feb 18, 2005, at 10:41 PM, Dan Allen wrote:

> Well, I received my 5 volt calibration standard from Joe Geller at 
> gellerlabs.com today.
>
> I upgraded to the KQ chip.  The papers with it shows that it is 
> calibrated to +/- 10 microvolts.  On a 5 volt scale, that is +/- 2ppm. 
>  The initial calibration is then +/- 0.0002%!
>
> I connected it to my Alinco DM-330MV switching power supply locked at 
> 13.8 volts.
>
> I then tested my Sears Craftsman 82002 autoranging multimeter.  It 
> displayed 5.04 volts.  That is an error of 4 parts in 500, or 8 parts 
> in 1000, or 0.8%.
>
> Next, I tested my HP 3466A bench-top DMM.  It displayed 5.000 volts 
> both autoranging and with the range manually set.
>
> I bought the HP meter used off of EBay for the purpose of aligning my 
> K2. The K2 has always seemed to be dead on (or spot on as our British 
> friends say), and I guess I now know why!
>
> The calibration standard from Joe Geller is a beautiful piece of work. 
>  I think it is well worth $25!
>
> Dan Allen
> KB4ZVM
> K2 S/N 1757
>
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