Comment by BetterGeiger | Hacker News Reader

Comment by BetterGeiger | Hacker News Reader

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Cool project! My business is Better Geiger (www.bettergeiger.com), I design and sell radiation detectors. I just hope people keep in mind the capabilities and limitations of those simple Geiger tubes. Radon was mentioned on the project website, yes technically radon decay products are detectable but pracfically a Geiger tube is reacting only to terrestrial, cosmic, and other sources of radiation, not anything to do with radon. Measuring radon generally requires a dedicated device (I recommend ecosense, at least until I get around to designing one). You correctly noted that such a tube can't accurately measure dose, that's because it is not energy compensated, so usually such a tube has a count to dose conversion factor for Cs-137 that will cause major overestimation in realistic scenarios. Those cheap tubes of that type also saturates easily in radiation fields that are really hazardous, making it fairly useless in an emergency situation. That is the main distinguishing feature of my products, high range and energy compensated. I have put out some YouTube videos that go into more detail about radiation dose, fallout and how to reduce risks, etc. I've given a lot of thought to doing a project like this with a scintillator, but I don't think the demand is there for me to do it before a lot of other ideas I have... When a cheapo standalone Geiger tube device can be had for $50, my products with scintillator go for $150 or $200 for the very high sensitivity version, then for $250-600 there are a few gamma spec products like radiacode, raysid, and radview with varying other features that are fun for hobbyists (though be aware none of those go to high dose rate range). For hackability mine offers access to the digital and analog outputs, but it's not really made for gamma spec so the spectrum quality is poor, but it can be a fun way to play. I've given a lot of thought to something designed more for DIY people, but in my experience very few people actually want that, most just want plug and play, and the ones that do request it usually don't even follow through. I've only communicated with a couple people that actually pulled a spec from a better geiger. Maybe that would be different if I designed a device specifically for DIY, something really small with simple serial comm output or something like that... Maybe some day.

Read above now and twice on Sunday.

I love the idea of using the tube and measurements as a random number generator! However, please treat the whole category of homemade devices to measure/detect "bad shit" as novelty and nothing else. If you are actually concerned enough to really measure/detect harmful materials, buy the proper devices. Learn how to calibrate and how to use them properly. The last thing our 911 system needs are people calling with aliexpress radiation detectors going off in a cancer center.

I would really like to have a geiger counter that I can put on the wall and connect to Zigbee/Z-Wave/WiFi and tie into Home Assistant. I've considered building one with the cheaper tube and ESP32, but I'm surprised that for Radon and radiation, it seems like something like AirGradient, but for radioactivity, doesn't exist.

You might be interested in RadiaCode (full gamma spectrum) and RadiaCode Python Library - https://www.radiacode.com/ and https://github.com/cdump/radiacode

For Radon detection options are

* direct alpha detection via wet film + process (slow, and day turnover physical processing) OR optical scintillation of filtered air, or

* stochastic gamma detection via a full spectrum and a formula to identify and divide out main peaks and daughter peaks of overlapping common radiometric decay (Uranium, Potassium, Thorium) to guesstimate the radon

I did this with radiacode and that library. I had chatgpt put together a quick little server that pushes from cdump/radiacode into MQTT for home assistant. I'd be happy to release it if there's interest.

I am not aware of anything that can connect to home assistant like that. It is definitely missing from the market and something I would like to make eventually, but too many other projects to finish first.

I use an Aranet radiation sensor[0] that ties in nicely with home assistant. It was more of a fun purchase, and excuse my lack of radiation knowledge, but is it same as those geiger counters or something a big different, I assumed it's similar but slower? They also have other sensors for Radon, CO2, etc

[0] https://aranet.com/en/home/products/aranet-radiation-sensor

Oh I didn't realize that worked with home assistant. It's a little different than a Geiger tube, that device uses a PIN diode and reacts to radiation interactions with the diode itself. Accuracy isn't great for dose but probably decent enough. Sensitivity is very very low, takes a while to get a reading. In theory it should be able to handle high dose rate levels but the spec sheet says it only measures to 1 mSv/hr which is pretty low, I don't know why. Their radon sensor is a different sensor tech, and CO2 and such is standard stuff pretty easy to implement.

> Radon was mentioned on the project website, yes technically radon decay products are detectable but pracfically a Geiger tube is reacting only to terrestrial, cosmic, and other sources of radiation, not anything to do with radon.

To measure radon (say in a cellar), you'd typically take some dust filter or filter foam, attach it to a fan and circulate the cellar air through the filter, then the radioactive dust collects in the filter, and one can measure higher doses more easily.

If you want to actually measure radon concentration quantitatively what you are describing is not the way. Typically devices simply measure alpha count rates coming from air, radon diffuses very effectively and no filtering or extra flow is necessary. Your technique would show "hey look there is a little bit of something radioactive here" but would be very difficult to turn into a concentration without a lot of extra complicated steps.

The relevance of the fan with filter is that it is analogous to your lungs which can also trap radioactive particles, like radon, causing say lung cancer.

Practically every radon measuring device on the market does it the way I described because of the reasons I described.

ah you are right, I mixed up, been awake for 2 days straight... I think it was one of the decay products or parent isotopes being trapped

No worries, I hope you can get some rest :)

Radon is a gas.

Yes, radon is a gas. Why did you bring this up? Were you implying that dust collection couldn't work? I can see why you might think that if you didn't understand that Radon is radioactive and has a short half-life (3.8 days).

> Most short term radon tests will use activated charcoal to absorb the radon gas in the air. Various short terms tests kits will include some type container filled with activated charcoal, usually perforated or screened and has a filter to keep out radon decay products. At the end of testing, the absorber is resealed and returned to the vendor for processing and evaluation.

> When radon undergoes radioactive breakdown, it decays into other radioactive elements called radon daughters (or progeny). Radon daughters are solids, not gases, and stick to surfaces such as dust particles in the air. Dust particles carrying radon daughters can move with air.

Amazing! Great work.

Random question for you in the biz: where can I get a muon detector setup? I just can't find them anywhere and would love to gain access to the extraterrestrial and solar weather particle environment.

I really want to make one to sell but too many other projects. The last time I saw them for sale was through the UKRAA but they seem to be out of stock for a while. You might be able to cobble one together with ebay stuff and online guides but it would be a struggle. Sorry I don't have a better answer.

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