Can I use a copper/zinc cell as a cheap, precise voltage source?

Thread Starter

whitehaired novice

Joined Jul 15, 2017
289
It has been several decades since I took a physics class, but I seem to remember that the voltage produced by two dissimilar metals in an electrolyte produced a known, constant voltage, independent of the electrolyte. The electrolyte did control internal resistance and current, but not voltage. So, if copper and zinc give a voltage of 1.100 can I cobble a temporary, low current, source accurate to thousandths of a volt? Do I remember the voltage correctly? Thanks
 
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Thread Starter

whitehaired novice

Joined Jul 15, 2017
289
OK--your second link shows 0.76 for zinc and 0.337 for copper so 1.097. Can I trust that? Or are there variables I don't know about?

I saw your first link some time ago; interesting but far, far, beyond my needs or desires.

Thanks.
 

wayneh

Joined Sep 9, 2010
17,153
There is also the issue of reagent purity. It wouldn’t be hard to get “close” but if you need precision, you’ll need high purity.

The short answer remains: this is a very tough way to establish a reference.
 

nsaspook

Joined Aug 27, 2009
8,515
There is also the issue of reagent purity. It wouldn’t be hard to get “close” but if you need precision, you’ll need high purity.

The short answer remains: this is a very tough way to establish a reference.
Correct, a electronic precision voltage reference is a no brainier but thousandths of a volt accuracy can be expensive.
My CL511 voltage spec:
 

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