[volt-nuts] Eppley Standard Cell and What Is It?

[J. L. Trantham]

I purchased an eBay item (190538109632) for the 'Standard Cell' that included another item.

What is it?

The 'Standard Cell' is an 'Eppley Laboratory Catalog Number 100 (SN 762058) Low Termperature Coefficient Standard of E. M. F.' that has written on it '1.01931 @ 20 degree C' with a date of what I think is '2-4-69' which I think means Feburary 4, 1969.

Using my 'new' Solartron 7081, I read the voltage at 1.017844 +/- about 1 uV.  If I have the math correct, that is a decrease of about 35 uV/yr which, I think, is about what is predicted for these cell's, assuming my 7081 is accurate.

I also have another Eppley Standard Cell (SN 821855) that reads 1.018709 but no date or prior reading on the unit.

On another, unrelated note, I have been able to chase down the US branch of Ametek in Oak Ridge, TN, and they will be getting my 7081 back to send to England for calibration and 'service best effort', given that the meter ceased production in 1998 with end of support 2008.  TAT is about 4 weeks in England.

Now, what is that other thing in the listing?

Joe