Currently I am investigating the lifetime or MTBF of GM Tubes.
Usually a maximum of Counts is specified on GM Tubes.
For example the SBM-20 from Russia has a total pulses lifetime of: at least 2*1010
However I have noticed that Tubes seem to get damaged faster than my expectation.
My Radex RD1503's SBM-20 GM tube died this year after hardly having used it.
Before some other tubes for older analog equipment also perished but with these I cannot rule out that the tubes were already used for a long time.
I would expect other sources of impact than normal usage as the single cause of malfunctioning of the GM Tube.
- Earthquake, shaking or dropping?
- Unexpected over Voltage?
- Preservation other than non-active/off-power needed?
To be able to monitor and rule out the maximum pulses when active as single cause the total accumulated pulses should be stored.
This could be done with the normal total Dose functions on many digital GM counters.
Of course you cannot be sure when the GM Tube was bought through an online auction like Ebay, that the Tube wasn't already used before.
Making a new GM counter with a LND712 GM Tube which has no lifetime specified...
Project progress to be continued.....