(picture: “Geiger Tube” by “dh” on Flickr, showing Russian SBM-20 hard beta and gamma GM tube)

On the internet there lots of DIY people showing off their homebuilt Geiger counter circuits, complete with microprocessors and LCD’s calculating and displaying count rates and often the dose rate in microsieverts/roentgen per hour.

The last thing surely makes a project look more impressive with the floating point number with a weird unit that most people are unfamiliar with. It’s not a big deal with DIY setups but there are lots of mentions of sending projects to Japan to help people over there “measure” contamination. Read more »