Elapsed time meter
Some Tektronix instruments up to the late 1980s contained electrochemical elapsed time meters based on the Mercury coulometer principle.
![](http://w140.com/tekwiki/images/thumb/3/3b/Mercury_coulometer.jpg/300px-Mercury_coulometer.jpg)
![](http://w140.com/tekwiki/images/thumb/3/3b/2794_A70_ElapsedTimeMeter.jpg/300px-2794_A70_ElapsedTimeMeter.jpg)
In case of disposal, this component will need to be handled according to local regulations dealing with parts containing mercury.
Instruments known to contain mercury-based elapsed time meters are
- 2336YA
- 490-Series spectrum analyzers Located on the A70 Z-axis & RF interface board
- 5110 Mod.WP
- 7503 – Curtis Indachron, Tek P/N 149-0030-00, run from +5 V via 3.9 MΩ. Located on rear of main interface board.
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