MightyOhm.com

Hi,
What radiation is your geiger counter capable of detecting? Can it detect alpha particles? I ask because I found that a lot of inexpensive geiger counters only detect beta and gamma radiation. I'm most interested to know if there is alpha radiation in food.
Or is the detection capabilities strictly a function of the Geiger-Muller tube? If so, what is the SBM-20, which comes with the counter capable of detecting?
Thank you
Joe

Hi Joe,

You are correct - the detection abilities are a function of the tube.

The SBM-20 detects gamma and hard beta radiation. It does not detect alpha particles. As you mentioned, alpha tubes tend to be considerably more expensive. The LND-712 is a readily available alpha/beta/gamma tube sold by Sparkfun: https://www.sparkfun.com/products/8875

Thanks for the super-fast answer,
Being a novice at electronics and physics, this question might be dumb. But the Geiger tube you refer to at sparkfun appears to be much smaller -- a completely different footprint. Will it fit in your kit? Are Geiger-Muller tubes all interchangeable?
Thanks,
Joe

It is electrically compatible, but it won't fit mechanically without modifications to the kit such as removing the top case and soldering wires to the tube.
Not all tubes are interchangeable. My kit only works with tubes that run around 400V. Some older American tubes require much higher voltages (around 1000V). These won't work.