Even though I don't have any real reason to have one, ever since I was a kid I wanted a Geiger Counter. So, long after I was a kid, I finally made a simple one and have amused myself and family pointing out our radioactive dish and glassware. It's based around the LND712 tube (alpha-beta-gamma detection) with a 3D printed enclosure. Even has a 555 chip
I don't suppose many people will copy my design since there is a bit of assembly but I put it up on github
https://github.com/danjulio/Geiger-Counter. The part that might be interesting to those who already have the high voltage circuit and a tube is the GUI display which runs on a super cheap ESP32 dev board ($8.33USD at
https://www.lilygo.cc/products/lilygo%C2%AE-ttgo-t-display-1-14-inch-lcd-esp32-control-board?variant=42159376466101).
Is it actually displaying reasonable numbers? 6.87 uSv/hr is about 40 times the normal background level. Was it measuring a nearby source of radioactivity when that photo was taken?
i wanted to make caps that you can put on that style so you can put filters for different radiation. I think its possible to do IIRC
@shaprius - yes, it was sitting next to a plate that has a radioactive glaze. Where I live, I get about 20 CPM background radiation. Using the 0.00833 CPM to uSv/Hr conversation factor I am using in this uncalibrated device that corresponds to around 0.17 uSv/hr.