Station is back online

The life of a GM tube caught my interest a little while back so I did some digging. Provided the tube is not damaged and the seals are good for the life of the tube the only factor in the lifespan would be the number of tube pulses that determines its life.
This is from Wikipedia :

The main component of the gas fill mixture is an inert gas such as helium, argon or neon, in some cases in a Penning mixture, and a "quench" gas of 5-10% of an organic vapor or a halogen gas to prevent multiple pulsing.[4] The halogen-filled G-M tube was invented by Sidney H. Liebson in 1947 and has several advantages over the tubes with older organic mixtures.[5] The halogen tube discharge takes advantage of a metastable state of the inert gas atom to more-readily ionize a halogen molecule than an organic vapor, enabling the tube to operate at much lower voltages, typically 400–600 volts instead of 900–1200 volts. It also has a longer life than tubes quenched with organic compounds, because the halogen ions can recombine while the organic vapor is gradually destroyed by the discharge process (giving the latter a life of around 108 events). For these reasons, the halogen-filled tube is now the most common.

Assuming the tube is the common SBM-20 and doing the following math assuming a background count of 20 CPM:
20 CPM per day totals 28800 tube pulses/day
This equates to 1051200 pulses/year

The specs for teh SBM-20 state 'at least 2*10^10 = 20000000000 (at least 20 billion pulses)
20000000000 / 1051200 pulses/year. = 19025.87 years

So, 19 Thousand years. I'm sure it would be less and I'm guessing the figures stated in the specs are in ideal and optimum conditions.

Bert490 wrote:

I can attest to long life for my old Electronic Goldmine LND-712 kit. I've used it intermittently for 20 years now.

I'm currently building a portable counter using the LND-712 so thats good to hear Bert490!