Re: ELECTRO-CHEMICAL ELAPSED TIME INDICATORS

On 12/14/2024 1:29 PM, Joe Gwinn wrote:

Curtis coulometers are analog Elapsed Time Indicators (ETIs) which use
an electro-chemical plating process to integrate current over time.

I have a box of these squirreled away in a box someplace. (Unfortunately I have a *lot* of boxes)
There was a paper card underneath the tube that you would slide to "zero" the meter.  And when it hit the end of the scale, the tube could be removed (like little fuse clips) and flipped over to count more. ISTR that if you allowed the electrolyte "bubble" to get all the way to either end of the tube the device was ruined.
The accuracy of the device was proportional to the accuracy of the current you passed through it.
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I'm part of the vast libertarian conspiracy to take over the world and leave everyone alone.