[Test-Equipment] Simple DC Voltage Standard?

[Barry]

Also, it would kind of surprise me if the 630 would be reading high.  I assume the range resistors are pretty stable even as old as it is, but I would suspect them to be high (resulting in a lower reading) rather than low.  Who knows, though.

Thanks,
Bary - N4BUQ


 On Mon 28/02/11  7:26 PM , Peter Wittenberg SR k2lrc at k2lrc.com sent:
> Barry, A new 1.5V battery is very close to 1.585 volts.  Most of a box will
> be the same. Test with your Fluke since it is the most stable of the
> bunch.
> -73- Peter K2LRC
> www.k2lrc.comGod Bless America !
> 
> When they call the roll in the Senate, the Senators do not know whether to
> answer "present" or "not guilty."  Theodore Roosevelt
> 
> -----Original Message-----
> From: test-equipment-bounces at mailman.qth.net [test-equipment-bounces at mailman.qth.net] On Behalf Of
> BarrySent: Monday, February 28, 2011 8:24 PM
> To: test-equipment at mailman.qth.netSubject: [Test-Equipment] Simple DC Voltage Standard?
> 
> I recently refurbished an HP-410B and want to perform a simple DC voltage
> calibration.   The problem is I don't have anything that I'm really certain
> is all that close to the 1V standard I need.  I have a variable-voltage
> supply and with a simple voltage divider, I can hit 1V easily but without
> something to properly measure it, I don't know when it's spot on 1V.
> I have a Fluke 25 DMM, an old Triplett 630-NA, and an HP-410C - none of
> which are in known calibration.  The Fluke and Triplett agree, but the
> HP410C reads a little lower than either of those for the same voltage.
> For example, if I set the variable supply through the divider so that the
> Fluke and Triplett both see exactly 1V, the HP410C reads about 0.85V.  Of
> course, without any of them in known calibration, I don't know which one
> would be correct.
> What I was wondering is how close should a fresh AA battery be to exactly
> 1.5V?  From what I can find online, all the specs state a AA battery's
> "nominal" voltage is 1.5V but I'm not sure how close to exactly 1.5V is
> considered "nominal".
> Oddly, the HP410C measures a fresh AA batttery at exactly 1.5V while the
> other two see it as about 1.625V.  I'm pretty sure 1.625V is quite high for
> a "nominal" AA and perhaps the Fluke and Triplett are both out of
> calibration about the same amount.
> Any suggestions on a "dirty" way to get really close to 1.0V?  I also have
> a Tek 465B 'scope but that, too, isn't calibrated so not sure how that
> might help get me where I want to be with this.
> Thanks,
> Barry - N4BUQ
> 
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