Phil Nelson wrote:
Any idea what this battery was used for? Found it at a flea market for $1.

The two-piece Bakelite case says The Bristol Company, Waterbury, Conn.
Inside are two glass capsules with different stuff in the bottom. The
bottom stuff in capsule looks like clay, the other looks like a ball of
wrinkled foil. A sticker on the left capsule says the Eppley Laboratory,
Newport, R.I.

Both capsules still contain liquid. They are cushioned in a tidy little
felt blanket.

Phil "just curious" Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

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Ha! That inside view is exactly the picture in my old
study books showing a standard voltage reference.
It might even still work.
If you want to test, use a high quality voltmeter,
and check its voltage.
DONT let it deliver any current, because it becomes
useless rather quickly.
In my book its called a WESTON ELEMENT, and used as a
calibration standard(very expensive).
On the plus site is mercury, covered with cadmium sulfate.
On the minus site is mercury+12percent cadmium, also covered
with cadmium sulfate.
The fluid is water saturated with cadmium sulfate.
The voltage should be 1.0183 volt at 20 degree Celcius.(68 F)
The book is from 1958

"Sjouke Burry" wrote in message
...
The book is from 1958

You learn something new every day. I had never heard of these. Can anyone
elaborate a bit on what exactly they were used in? Calibrating what,
meters?

Buck Frobisher wrote:
"Sjouke Burry" wrote in message
...
The book is from 1958

You learn something new every day. I had never heard of these. Can anyone
elaborate a bit on what exactly they were used in? Calibrating what,
meters?


Anyplace/time you needed an accurate voltage.
In the lab you had very accurate resistor divider banks,
where you reduced your test-voltage to the same voltage
as the cell.
That was tested with a very sensitive galvanometer,
where, when the galvanometer indicated zero (micro)volt
difference between the two, your testvoltage followed
From: Vtest=bankratio X cellvoltage.
In this way, at the moment of the readout, the cell did
not supply any current, and thus the error was minimal.

And yes, meter calibration,reference source calibration
(current and voltage) were ever needed.
And even to calibrate these reference cells, because due to
impurities non of these cells had exactly the same voltage.
Now, how to calibrate the first one? I have no idea, but in
most countries you had a standards lab to do that for you.