HP 8753A/B/C non-volative memory

[SteveReeves]

Does anyone know about how long the non-volative memory of the HP 8753A/B/C should last? This is the memory portion where the user may store instrument states. The manual says > 72 hrs (I think it's much longer actually). The memory is maintained by a 0.22 Farad cap on the microprocessor board - no battery. I was curious because we're seeing several come in for calibration and when turned on they clear their memory registers at power up.

 

[barryabrown]

At room temperature, it lasts about a week, as I recall.