Two-dollar dosimeter

Posted on 25th Apr 2018

Some time ago I bought an Arduino set to implement my (basic) programming skills into the real world. It didn’t take long for me to look for a way to build a light sensor and test it if it responded to x-rays…and it did. So, I started wondering, how cheap would I be able to build a radiation detector.

Looking around the web it is easy to find kits using Geiger-Müller tubes but given the limit of Geiger-Müller tubes with detecting higher doses I wanted something else. So, I went for the next best thing I could think of, photodiodes. Just like smartphones these contain semiconductor material which creates a small current when hit. This current should be detectable by the Arduino I thought…and it was but I had to use the maximum tube load and voltage. But version one was there at a cost of roughly 25 euros!

After some snooping around I came across some cheap photodiodes with a larger surface and therefore better voltage-output. But more interesting I came across the attiny85 chip which could easily be programmed using an Arduino. Seeing as the Arduino was no longer needed in the setup the cost was drastically reduced to about two euro!

The script involved isn’t very exciting and largely taken from the light theremin described in the guide.

All in all, it is fun toying around and learning more about electronics doing so. I’m trying to see if it is possible to create a student project around this in order to create a more practical version.

If there are any major developments I will post them here.