Geiger Counter (Radioactivity Meter)

How can I measure radioactivity?

Within my fondness for measuring and controlling everything, I've been thinking about adding a sensor detector to my sensor list for a long time. Beta and Gamma emissions (what we usually call a radiation meter), a Geiger-Muller counter or Geiger meter.

And why do I want a Geiger counter? Well, very simple, because I know that sooner or later an accident will happen or we will suffer an attack and our governments will hide the information from us (look for information about the accident that occurred in Madrid, in Moncloa, in the heart of the University City, and you will see what I am talking about). And, although they do not hide it from us, I want to be informed first hand and know what happens in our environment.

Also on some occasion when they have made a reference to radiation in the news, it has been good for me to have my own Geiger counter and to be able to measure radiation, when it has suited me.

For example, when they said that the fish we were eating was contaminated, putting it down to being affected by Fukushima radiationYou can analyze the fish we brought home, which gave us extra peace of mind (and I know that there are people who analyze the fish daily with meters similar to this one).

Well, the fact is that recently I have encouraged myself with its construction and it is already working.

Make a Geiger counter from scratch?

I spent a lot of time thinking about how to do it. A really Geiger counter It is very simple, basically consists of a detection tube, a high voltage source (the tube operates at about 450 volts, approximately) and a circuit scaler that are generated in the tube depending on the amount of radioactive particles in the environment.

One possibility was to build a high voltage generator for one (easy enough, a few capacitors and diodes) and a counter (a simple Arduino). Would be missing the tube, which I will now talk about, and some way to view the results (an LED, LCD or OLED display, a computer connection or something similar).

Build a Geiger Counter Kit?

Looking for information about it, I found that it was not worth designing it and doing it from scratch. I found a kit on eBay that, for about € 30, it provided practically everything (in the absence of the tube).

I decided to order this kit and in a couple of weeks I already had it at home, from Lithuania.

I could save the work of designing it and spending that time improving the meter, providing it with Wifi and connecting it to the internet, for example.

Geiger counter mounting

The assembly of the kit was frankly simple since the approximately 50 SMD components that it carries are already soldered to the board and only a few normal components have to be soldered. Even a beginner could do it without any problem, with a little care.

The STS-5 Beta and Gamma Detection Tube

The heart of the Geiger counter is the Beta and Gamma ionizing radiation detection tube STS-5.

There are many different tubes with different sensitivities and able to detect different types of radiation (alpha, beta, gamma, x-rays, etc.).

Although it is about laboratory equipment, highly sensitive, contrary to what we might think, its price is not high.

We have at our disposal a large number of surplus tubes, from the former Soviet Union, from the cold war era, which are easy to find on the internet and whose prices usually oscillate between € 15 and € 30.

In my case I decided on an STS-5 tube from Ukraine. For € 15Including shipping, in just over two weeks I had my new tube at home.

3D printed box

Finally, and to complete my new Geiger-Muller detector, and give it a good finish, I was missing a box to put it in.

Fortunately, I found in Thingiverse a custom box for the kit I had ordered, so that in a couple of hours my 3D printer had "spit out" a more than apparent box (to which I have made a yellow vinyl front with my cutting plotter to give a more professional finish).

Send the radioactivity data to the internet

There was one last detail, but, for me, the most important: connect Geiger counter to internet and capture the data it generates, create graphs, alarms, etc..

The kit and its firmware already include a Serial port able to extract this data, so the next step will be complete the detector with an ESP8266 (that I want to put inside the same box) and that will be in charge, connected to my Wi-Fi network, to send the data to the rest of the systems in my house. But this will be the subject of a new blog post ...

Edito: You can find this new article on how to send radioactivity data to the internet in real time in this page