Elapsed time meter

Some Tektronix instruments up to the late 1980s contained electrochemical elapsed time meters based on the Mercury coulometer principle.

Curtis elapsed time meter (149-0030-00) in a 7503 scope

Elapsed time meter on A70 board in a 2794 spectrum analyzer

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.
• 7L5 - Curtis Indachron, located on rear of digital storage and averaging board. Shown as M4770 on pg 217 of service manual.
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