Electronics > Metrology

From the bin!-- weston cell +meas. data & lastly Muirhead Cat. data sheet

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lowimpedance:
While inspecting the dumpster for anything useful (as you do  :D) I came across this unloved item from 'Muirhead'. (1960 vintage). Missing its cosy protective outer casing !.
Quick test with an high impedance input DMM to minimize loading. Still a good reading ?? .....well who knows. Not about to give up on the somewhat more modern stuff for this old timer  :P.
Any way with the nasties contained inside it should be disposed of a little more carefully next time!.

Final edit : I have added the Muirhead catalogue data sales sheet at the end of the thread.

Kilrah:
Someone who's found that thing in a box in the attic and has no clue about it.

edpalmer42:
FYI, here's more than you ever wanted to know about Standard Cells:

http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS84.pdf

According to this document, an unsaturated cell has a life of 23 to 37 years under perfect conditions or 12 to 18 years under realistic conditions.  If that '60' that I see is the year of manufacture, this thing is long past its best before date.  They say that the minimum voltage is 1.01830 so you've got some room there.

You should check the internal resistance of the cell.  It should be in the 100 - 500 ohm range.  The other thing that happens with age is that the temperature characteristics degrade.  I've got a couple of Eppley unsaturated cells.  They aren't useful anymore because the voltage isn't stable even at a constant temperature.

Ed

Sbampato12:

--- Quote from: edpalmer42 on August 04, 2016, 06:14:03 pm ---FYI, here's more than you ever wanted to know about Standard Cells:

http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS84.pdf

According to this document, an unsaturated cell has a life of 23 to 37 years under perfect conditions or 12 to 18 years under realistic conditions.  If that '60' that I see is the year of manufacture, this thing is long past its best before date.  They say that the minimum voltage is 1.01830 so you've got some room there.

You should check the internal resistance of the cell.  It should be in the 100 - 500 ohm range.  The other thing that happens with age is that the temperature characteristics degrade.  I've got a couple of Eppley unsaturated cells.  They aren't useful anymore because the voltage isn't stable even at a constant temperature.

Ed

--- End quote ---

I have one from Eppley also. But I did read somewhere that we don't should connect direct on DMM inputs, I'm not sure about that.

Vgkid:
Surprised that it survived intact. Even more that it appears to be working correctly.

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