Ever since I was a child I’ve wanted a Geiger counter. Recently the perfect opportunity arose that I sought to take advantage of. There is a required creative project in my particle & nuclear physics course. In addition, I realized that I could give a presentation on radiation detection and building a Geiger counter in my physics communication course. What’s that old saying, “Kill two birds with one stone” (well technically three, but whatever). So after some thinking and planning I finally decided to build a Geiger counter.
Now I had some choices to make: to go the hardcore DIY route (building the circuit myself), or obtain a pre-fabricated Geiger counter circuit board. The idea of creating one from scratch and acquiring all of the parts from a local electronics store is enticing, however it would probably end up a functioning, big, ugly mess with wires and parts all over the place. So, I decided to take the path of least resistance that would result in a device that is much more portable and functional. I bought a kit that includes everything you need (besides the tools, Geiger-Müller tube, batteries, wires, and switches) from diygeigercounter. I ordered mostly everything else I needed, and then waited for the packages to arrive like it was Christmas eve.
Upon beginning the journey I realized that the soldering was going to be a serious undertaking for someone who hasn’t soldered more than two wires together before. The solder I had originally ordered was way too large to use. Once I obtained the correct size solder I was on my way. The soldering at first was all about getting used to it. After a dozen or so resistors I was starting to get the hang of it. A helping hands device was really convenient to have and a smart purchase. After a few rookie mistakes and more time than I’d like to mention, I finally completed what I consider to be a good first soldering job.
After popping on the LCD (sold separately from the kit), connecting the tube, and 9V battery, I started to hear clicks! I thought to myself, “Thank God”. I would’ve been pretty mad if I had just spent all that time and ended up with a complete dud. I then tested the Geiger counter with a thorium lantern mantle (obtained via Ebay) and got counts fluctuating around 1308 counts per min. “It’s working!”
Now all that was left was to find/make/buy a housing for it, and install a power switch. I ended up going with a Pelican micro case I found at Best Buy. It was fairly inexpensive and has the added benefits of being water-proof and crush-proof. I obtained a switch from Radioshack and connected it to the battery and the board. I’ll probably also eventually add switches for display on/off and click/off/tone mode. One thing I have noticed is that the case blocks most beta particles. This is due to it being the thick crush-proof plastic. There are three options: open the case when using, drill holes near the tube, drill a hole in the side for an external tube to be used in a wand-like apparatus. The latter is the most appealing to me as the case can still be waterproofed that way. After all was said and done, I was pretty happy with the outcome.