This project is neat and OP did a good job, but I think the interest in Geiger counters among hackers needs an update. The Geiger kit on Adafruit (Yes, I know that makes the cost a lot higher to be from them instead of Ali, but I think is a good baseline for "finished good" price) is $99.
Meanwhile, Raysid or Radiacode let you do full on gamma spectrometry, for about 2.5x the price.
And, like, yeah, 2.5x the price. I'm not oblivious to that being significant, but to me it's sorta like an GT1030 with DDR4 - it's about $100 or you could get an RTX 3060 for a bit over $300. Like, you might have a use where you ONLY need a cheap display card, but there's a reason LTT calls the 1030 eWaste from the factory. Similarly, you might get enough out of the Geiger or it might do something the Radiacode doesn't for you but for most hobbyist, I doubt it.
I gave a more detailed comment already, but price/performance is not a simple two axis thing. No consumer grade gamma spec device measures high dose rate which is needed for emergency use. Depending on the intended use case something lower cost than radiacode might make sense. For example the radiacode 110 ($400) has the same volume and type of scintillator, with very high sensitivity, as the better geiger S2L ($200), so both are good for handheld search for radioactive objects, but S2L has something like 30x higher maximum dose rate range which makes it more capable in emergencies, whereas the 110 has Bluetooth, mapping, and gamma spec... Which are very fun for hobbyist but have little true "practical" real world value. Different interests and different budgets would point people in different directions.
Yeah, even in the non-consumer grade space, you're still likely to want to include something like a calibrated GM tube in the lineup, for measuring dose after the scintillators are saturated.
Yes exactly, often a small energy compensated GM tube that is not very sensitive but can handle very high radiation levels is included in the same device as a pro detector with a fancy scintillator.
> Like, you might have a use where you ONLY need a cheap display card, but there's a reason LTT calls the 1030 eWaste from the factory. Similarly, you might get enough out of the Geiger or it might do something the Radiacode doesn't for you but for most hobbyist, I doubt it.
I think the biggest difference here is that GPUs are fairly general-purpose devices. Even if you only need one as a cheapest possible way to output something to your monitor, it's easy to imagine how that might change and why you might as well future-proof your setup.
The other thing you didn't mention about why a 1030 is manufactured e-waste is in large part the competition from the used market. You can get equivalent functionality for a few dozen dollars, so buying a brand new 1030 as an individual makes no sense. This isn't a problem in the specialty radiation device market.
The thing is that most people probably don't buy Geiger counter modules or devices because of a burning need to do some specific tasks, like you would with GPUs. I'll bet that most people buying the Adafruit kit are getting it as a novelty, or for educational purposes, or to just have something reporting the background radiation around them out of curiosity. Because of this, price is the most important factor for these groups.
I've never heard of Radiacode, and looking it up, it seems seriously impressive - especially the portable gamma spectrometry that you mentioned. But I also know that it's a very niche device, and most people who would shell out $250+ for this need it for chemistry projects, exploring irradiated areas, evaluating radioactive items and so on. It's not a lot of people, considering that if you just want something to give you a readout, you'll get the <$99 product, and if you need it occupationally, you'll already have received a professional device.
Maybe? I feel like the most in group of people who do have the discretionary income to toss $100 at a Geiger counter for fun also have enough to toss $250 at it and would rather given the extra utility. I might be wrong though. And it certainly depends as the $100 line drops. If it's $50 for a Geiger, that's a lot closer to "I don't care money"
I had someone tell me a while back $100 is an adult $20. As in, what you saw as a kid as $20 of fun but factoring in how long it took you to get the $20, it's about the same. I know that math will be massively variable, but I like the idea of equating kid brain money to adult money for "toys" like this. A $5 toy vs a $40 toy, as a kid, is a big deal. A $40 toy vs a $70 toy almost isn't, because they're both already "expensive".
I suspect for most on HN, their toy-money equivalence leans to the Radiacode or equivalent being the better buy.
I agree, I'm not the most representative of HN users, so I can't gauge how willing one of them might be to pay the higher price. Maybe someone making six figures in the US (the average user on here?) wouldn't mind it, but I imagine that if we look at all techy people and not just HN, things would be closer to the mean.
For me, a $100 purchase is something I can probably justify if I think I'll enjoy it a lot. $250 is still a 2.5x upcharge, and I consider these expenditures for a long time, making sure that I really actually need it.
And then, the $100 is just an example reference. It's sold by Adafruit, whose selling point is trading some value in exchange for reliability, convenience and compatibility. When you look at the market in general, I can find countless cheap pre-built Geiger counters at prices that are a lot closer to $50. I can't vouch for their accuracy, but there are so many unique options that I imagine that at least a few will be pretty decent.
For staying safe you want high max range and energy-compensated dose response. No ultra cheap devices offer that, mine is the closest thing on the low end of price, but consider me biased... If anyone finds something to contradict that feel free to share, because it would be new info to me. Then there is the second hand market, for example mrad 113 is a good device that can sometimes be had for a reasonable price, probably there are other pro grade dosimeters on ebay for a reasonable price but I don't know follow that market closely.
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.
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.
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
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.
* 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
> 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.
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.
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.
I know that footguns are broadly "on-brand" for the flipper zero ecosystem, but exposing high-voltage leads like that without any warning whatsoever seems a bit much.
I don't know about the details of this device, but in general, simply being high-voltage doesn't automatically mean it's dangerous. One of the machines I work with in my day job has probes that put out around a thousand volts, but it's totally safe to touch them with your bare hands. You won't even feel a tingle.
That said, it's always prudent to treat any live electrical line as dangerous unless you know for a fact that it isn't, of course.
Why is the 1000v safe? My guess is energy released is small e.g. a small capacitor. Or internal resistance is high so it becomes much less when you touch it. Or you mean touch one end and it is DC.
I'm no EE, but my understanding is that it's partially because the amperage is very low and partially because the signal is AC operating at a frequency that causes a large impedance mismatch between the probe and people.
It's counterintuitive enough that the probes actually have an "anti-warning" label to inform people that they are safe to touch.
High voltage means nothing if the power source can't deliver the current. You could use a transformer to step up a AAA battery to a billion volts and it wouldn't do anything because a battery can't actually push out 1B/[your body's resistance] amps.
With low voltage battery circuits the main thing you have to be wary of is capacitors because those can push out a lot more current than the battery itself. Usually you can judge how much a capacitor would hurt if you touched it based on its size. If you have a device with 20 batteries charging a baseball sized capacitor, be very cautious (like the DIY gauss guns/rail guns you see on youtube). Even a thimble sized capacitor will jolt you surprisingly hard. One time I touched the charged capacitor of a disposable camera and the discharge gave me quite the zing.
> High voltage means nothing if the power source can't deliver the current
It can still be dangerous though, it can trickle charge an output capacitance which will deliver the current to hurt you. A small battery only charges it more slowly, the end result is a function only of voltage (assuming the battery has sufficient capacity to completely charge the capacitance).
The suggested board is powered by USB, that's 5V 500mA, so, 2.5W. Let's say the tube is run at the recommended 380V, at 2.5W, that's a current of 6.5mA, which is barely painful, and not dangerous. I guess that with that power, if the circuit really wanted to hurt you, it could boost the voltage in the 50-100V range for a ~30mA shock, which is definitely painful and the start of what is considered dangerous. Electric safety is complicated, there is so much to take into account: current, voltage, frequency, location, presence of water, etc... Skin resistance is far from constant.
Maybe it could do more if it disregards the 500mA USB limit to the full 1.2A that the Flipper Zero can deliver, or with capacitors, but it doesn't seem to have enough of them for a significant power reserve. If it could do that, I would also worry about plugging it to my Flipper Zero or to anything of value out of fear of damaging it, as it would have to be of pretty terrible design, but well, that's AliExpress after all.
I believe it also doesn't make a lot of sense to have a real Geiger tube and have it exposed.
For the sexond, Geigers are binary, they only report detection events, not types. So you don't want it to be triggered on non-X rays like interferences from computers around, and you might also want to be able to occasionally remove surface contaminants from the equipment. Both of these are easily achieved by giving it a durable opaque case which is how everybody do these.
And for the first, I believe a modern photodiode taped over is by itself more sensitive than Geigers, even more so if coupled to a scintillator crystal(salts that glows in x-rays), not to speak of spectrometer based systems that can additionally tell energy levels therefore types and biological damage levels of incoming rays.
The real Geiger tube running on display is cool, but that's strictly it. I believe.
15mA is the limit in my brain. Im sure someone will chime in with a different number but its around here.
The thing to remember is the output impedance. You can have 1000's of volts at a node, but its sourced by a VERY high impedance output. so when you touch it with your hands (which is like 100kohm on a dry day), the voltage collapses because of the voltage divider your hand created.
But if the output impedance is low (transmission lines), well its game over.
But even beyond that, the maximum power output will still be pretty limited. If you short the HV rails, it will almost certainly start to drop in voltage and raise in current quickly, but only to the limits of the resistance from other elements in series and the power source's output ability. I strongly doubt you could even make something dangerous from the Flipper, at least unless you attach a large cap, let it charge slowly, and attach a taser module.
Talking a bit out of my ass here as someone whose EE experience ended at graduation, but a good general rule is if you stay below 5 mA continuous, it is rather difficult to injure yourself. For extremely short shocks (like you get when you discharge a capacitor across yourself) you can get away with a lot more than that, though.
I would be rather surprised if a device that is powered off a lithium ion battery like the one in the Flipper Zero managed to seriously injure someone.
Yep, and even with AC, it depends on the frequency. There are a ton of variables affecting how dangerous electricity is to people, so it's hard to make general statements about it.
Chinese Geiger counter kits sometimes include a single piece of plexiglass or nothing at all. I have one I only use when placed inside a plastic bag, so it's not going to be detecting any α. I haven't yet put it up against my CDV-717.
You can get a standalone (cheap) Geiger counter like the GQ GMC-300S on Amazon (B0B541D433) for ~$50. If you're interested in monitoring radiation and have a higher budget to play with, I highly suggest stepping up to the Radiacode 103G (~$600) or the Radeye B20-ER (~$3000). The Radiacode can only detect gamma/x-ray, but is a spectrometer so it can determine the energy level of the radiation. The Radeye can do the full suite of γ α β, and can provide energy-compensated dose rates when its gamma filter is in place.
If you have one of those small scintillators on you all the time you can measure your own radiation. A significant spike in the spectrum for Potassium-40.
The only thing I can find radioactive enough to be picked up by a cheap GM tube kit is vintage real green uranium glassware. Even a giant bunch of bananas doesn't increase counts enough. Smoke detectors also don't seem to be radioactive enough either.
When I was playing with arduino geiger counter, apart from of course breaking the tube, I struggled with counting the results.
On one hand it's trivial - counts (ticks) per second. However, this (of course!) can be very spiky. I ended up using pretty simple EWMA to smooth the results for user interaction. Anything really works, short decay is fine.
Then the really fun bit, was trying it with more serious radiation source, and guess what.... interrupt per tick, is... really bad! I was easily able to overwhelm the arduino, too many interrupts. Fun project to understand interrupt masking.
Back in my SIL4 days, we had a de-capped memory SIMM in the lab that we used to test resilience to cosmic rays for certification and other testing procedures .. often requiring a junior dev to sit there waiting for the signal and remove the lead shield we'd place over it when not testing, in order to trigger a cosmic bit shift. We had t-shirts for those guys "Guardian of the Cosmic Bit" printed up, was a fun time ..
This is cool, but if you're ever in need of a dope present, especially for someone like your father-in-law, Better Geiger[1] is awesome. My FIL was stoked. Loves checking the bananas at costco and other random stuff at costco.
This reminded me about a wtf moment back in 2008. New York City tried to make it illegal (misdemeanor) to posses a geiger counter without a license. Obviously, it never became law.
I bought a few Geiger tubes about 10 years ago. The larger one is more sensitive, but doesn't detect beta radiation. The smaller one does alpha/beta/gamma, but it's less sensitive. When you buy the tubes, you don't get the benefit of a calibrated measurement device, so I also bought a few Cesium 137 calibration sources. (No idea what sort of government watch lists I ended up on after placing that order.)
Next, I built a simple Geiger counter based upon a Raspberry Pi (Model B) and a Piface LCD display. I wanted to increase dynamic range of the measurements, so I did some circuit modifications to recharge the Geiger tube faster after an event. This allowed for higher counts, but consumes more power and lowers sensitivity. Also, getting the Pi to interrupt on each event for efficient counting has its limitations. A separate digital counter that is reset upon each read sample is better.
Anyway, it's a rabbit hole that ended up taking a lot more time and effort than I expected, but I was happy with the results.
Hypothetically speaking, how useful would something like that be in a nuclear weapon fallout scenario? Can such a contraption detect the important isotopes and give the user an accurate idea of the level of danger they're in, does that change over time as isotope composition changes through decay?
tl;dr not useful. To make a long story short, max range is very important and these cheap tubes saturate easily, and they don't give energy-corrected dose rate. They also cannot do gamma spec (isotope identification), but that is not needed for a fallout scenario because fallout contains basically every isotope under the sun, no need to do any gamma spec. I have a very long detailed video about this topic on my youtube channel BetterGeiger
It's cute, looks nice, and bravo for shipping something, but FZ is too hyped and too expensive for what it is.
I have a similar Geiger counter that functions standalone and works as an Arduino module. It doesn't appear to be very sensitive because bananas don't increase counts. The only household object able to barely increase counts was some vintage uranium glass tucked away in a corner behind a display case.
I am not certain but this tube looks like an M4011 which typically measures up to 1 mSv/hr for a reference Cs-137 source. Pretty low maximum level, not suitable for emergencies.
Do a search for "MightyOhm Geiger Counter Kit Bundle" and you will find a stand alone version of the same circuit along with photos. Although the PCB has a "High Voltage" label, it is powered by 2 X AAA batteries which are might be very lethal if ingested.\s
Powered by 2x AAA batteries != not high voltage. Boost converters can reach high voltages pretty easily. That's why you can get USB powered nixie clocks, for example.
You can shock the hell out of yourself with the capacitors for the flash in a disposable camera, so the AAA battery source isn't exactly exculpatory...
This project is neat and OP did a good job, but I think the interest in Geiger counters among hackers needs an update. The Geiger kit on Adafruit (Yes, I know that makes the cost a lot higher to be from them instead of Ali, but I think is a good baseline for "finished good" price) is $99.
Meanwhile, Raysid or Radiacode let you do full on gamma spectrometry, for about 2.5x the price.
And, like, yeah, 2.5x the price. I'm not oblivious to that being significant, but to me it's sorta like an GT1030 with DDR4 - it's about $100 or you could get an RTX 3060 for a bit over $300. Like, you might have a use where you ONLY need a cheap display card, but there's a reason LTT calls the 1030 eWaste from the factory. Similarly, you might get enough out of the Geiger or it might do something the Radiacode doesn't for you but for most hobbyist, I doubt it.
I gave a more detailed comment already, but price/performance is not a simple two axis thing. No consumer grade gamma spec device measures high dose rate which is needed for emergency use. Depending on the intended use case something lower cost than radiacode might make sense. For example the radiacode 110 ($400) has the same volume and type of scintillator, with very high sensitivity, as the better geiger S2L ($200), so both are good for handheld search for radioactive objects, but S2L has something like 30x higher maximum dose rate range which makes it more capable in emergencies, whereas the 110 has Bluetooth, mapping, and gamma spec... Which are very fun for hobbyist but have little true "practical" real world value. Different interests and different budgets would point people in different directions.
Yeah, even in the non-consumer grade space, you're still likely to want to include something like a calibrated GM tube in the lineup, for measuring dose after the scintillators are saturated.
Yes exactly, often a small energy compensated GM tube that is not very sensitive but can handle very high radiation levels is included in the same device as a pro detector with a fancy scintillator.
> Like, you might have a use where you ONLY need a cheap display card, but there's a reason LTT calls the 1030 eWaste from the factory. Similarly, you might get enough out of the Geiger or it might do something the Radiacode doesn't for you but for most hobbyist, I doubt it.
I think the biggest difference here is that GPUs are fairly general-purpose devices. Even if you only need one as a cheapest possible way to output something to your monitor, it's easy to imagine how that might change and why you might as well future-proof your setup.
The other thing you didn't mention about why a 1030 is manufactured e-waste is in large part the competition from the used market. You can get equivalent functionality for a few dozen dollars, so buying a brand new 1030 as an individual makes no sense. This isn't a problem in the specialty radiation device market.
The thing is that most people probably don't buy Geiger counter modules or devices because of a burning need to do some specific tasks, like you would with GPUs. I'll bet that most people buying the Adafruit kit are getting it as a novelty, or for educational purposes, or to just have something reporting the background radiation around them out of curiosity. Because of this, price is the most important factor for these groups.
I've never heard of Radiacode, and looking it up, it seems seriously impressive - especially the portable gamma spectrometry that you mentioned. But I also know that it's a very niche device, and most people who would shell out $250+ for this need it for chemistry projects, exploring irradiated areas, evaluating radioactive items and so on. It's not a lot of people, considering that if you just want something to give you a readout, you'll get the <$99 product, and if you need it occupationally, you'll already have received a professional device.
Maybe? I feel like the most in group of people who do have the discretionary income to toss $100 at a Geiger counter for fun also have enough to toss $250 at it and would rather given the extra utility. I might be wrong though. And it certainly depends as the $100 line drops. If it's $50 for a Geiger, that's a lot closer to "I don't care money"
I had someone tell me a while back $100 is an adult $20. As in, what you saw as a kid as $20 of fun but factoring in how long it took you to get the $20, it's about the same. I know that math will be massively variable, but I like the idea of equating kid brain money to adult money for "toys" like this. A $5 toy vs a $40 toy, as a kid, is a big deal. A $40 toy vs a $70 toy almost isn't, because they're both already "expensive".
I suspect for most on HN, their toy-money equivalence leans to the Radiacode or equivalent being the better buy.
I agree, I'm not the most representative of HN users, so I can't gauge how willing one of them might be to pay the higher price. Maybe someone making six figures in the US (the average user on here?) wouldn't mind it, but I imagine that if we look at all techy people and not just HN, things would be closer to the mean.
For me, a $100 purchase is something I can probably justify if I think I'll enjoy it a lot. $250 is still a 2.5x upcharge, and I consider these expenditures for a long time, making sure that I really actually need it.
And then, the $100 is just an example reference. It's sold by Adafruit, whose selling point is trading some value in exchange for reliability, convenience and compatibility. When you look at the market in general, I can find countless cheap pre-built Geiger counters at prices that are a lot closer to $50. I can't vouch for their accuracy, but there are so many unique options that I imagine that at least a few will be pretty decent.
Which is the best inexpensive Geiger counter and which features probably don’t matter if you want to stay safe?
For staying safe you want high max range and energy-compensated dose response. No ultra cheap devices offer that, mine is the closest thing on the low end of price, but consider me biased... If anyone finds something to contradict that feel free to share, because it would be new info to me. Then there is the second hand market, for example mrad 113 is a good device that can sometimes be had for a reasonable price, probably there are other pro grade dosimeters on ebay for a reasonable price but I don't know follow that market closely.
Tangential, but this is the right crowd to know: what's the best digital visible light spectrometer in that kind of price range?
Let's be fair, adafruit is expensive.
https://www.aliexpress.com/item/1005004551394154.html this is 32eur
+ ~5eur for an esp32 board and some wires
+ http://docs.espgeiger.com/output/webportal
This gives you a measurement node, with mqtt support, online data export and a web interface.
For ~40eur all together, it's still very cheap.
Yeah there’s definitely a price and price/performance thing with these. You’re right in that I’d rather have the Radiacode.
I do like my Flipper for how adaptable it is but then end up using it to copy RFID tags as primary purpose.
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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.
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.
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
> 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.
I know that footguns are broadly "on-brand" for the flipper zero ecosystem, but exposing high-voltage leads like that without any warning whatsoever seems a bit much.
I don't know about the details of this device, but in general, simply being high-voltage doesn't automatically mean it's dangerous. One of the machines I work with in my day job has probes that put out around a thousand volts, but it's totally safe to touch them with your bare hands. You won't even feel a tingle.
That said, it's always prudent to treat any live electrical line as dangerous unless you know for a fact that it isn't, of course.
Why is the 1000v safe? My guess is energy released is small e.g. a small capacitor. Or internal resistance is high so it becomes much less when you touch it. Or you mean touch one end and it is DC.
I'm no EE, but my understanding is that it's partially because the amperage is very low and partially because the signal is AC operating at a frequency that causes a large impedance mismatch between the probe and people.
It's counterintuitive enough that the probes actually have an "anti-warning" label to inform people that they are safe to touch.
High voltage means nothing if the power source can't deliver the current. You could use a transformer to step up a AAA battery to a billion volts and it wouldn't do anything because a battery can't actually push out 1B/[your body's resistance] amps.
With low voltage battery circuits the main thing you have to be wary of is capacitors because those can push out a lot more current than the battery itself. Usually you can judge how much a capacitor would hurt if you touched it based on its size. If you have a device with 20 batteries charging a baseball sized capacitor, be very cautious (like the DIY gauss guns/rail guns you see on youtube). Even a thimble sized capacitor will jolt you surprisingly hard. One time I touched the charged capacitor of a disposable camera and the discharge gave me quite the zing.
> High voltage means nothing if the power source can't deliver the current
It can still be dangerous though, it can trickle charge an output capacitance which will deliver the current to hurt you. A small battery only charges it more slowly, the end result is a function only of voltage (assuming the battery has sufficient capacity to completely charge the capacitance).
Did you just invent a taser :)
Geiger counter with built-in taser. It's a feature, not a bug.
Fallout vibes
It is significant though?
The suggested board is powered by USB, that's 5V 500mA, so, 2.5W. Let's say the tube is run at the recommended 380V, at 2.5W, that's a current of 6.5mA, which is barely painful, and not dangerous. I guess that with that power, if the circuit really wanted to hurt you, it could boost the voltage in the 50-100V range for a ~30mA shock, which is definitely painful and the start of what is considered dangerous. Electric safety is complicated, there is so much to take into account: current, voltage, frequency, location, presence of water, etc... Skin resistance is far from constant.
Maybe it could do more if it disregards the 500mA USB limit to the full 1.2A that the Flipper Zero can deliver, or with capacitors, but it doesn't seem to have enough of them for a significant power reserve. If it could do that, I would also worry about plugging it to my Flipper Zero or to anything of value out of fear of damaging it, as it would have to be of pretty terrible design, but well, that's AliExpress after all.
I believe it also doesn't make a lot of sense to have a real Geiger tube and have it exposed.
For the sexond, Geigers are binary, they only report detection events, not types. So you don't want it to be triggered on non-X rays like interferences from computers around, and you might also want to be able to occasionally remove surface contaminants from the equipment. Both of these are easily achieved by giving it a durable opaque case which is how everybody do these.
And for the first, I believe a modern photodiode taped over is by itself more sensitive than Geigers, even more so if coupled to a scintillator crystal(salts that glows in x-rays), not to speak of spectrometer based systems that can additionally tell energy levels therefore types and biological damage levels of incoming rays.
The real Geiger tube running on display is cool, but that's strictly it. I believe.
I'd highly recommend printing an enclosure for it.
Is there a schematic? How high we talkin?
Hundreds of volts
but how many amps though?
How many is safe? I don't mean that facetiously - do you have a good understanding of a safe power limit on a source at hundreds of volts?
15mA is the limit in my brain. Im sure someone will chime in with a different number but its around here.
The thing to remember is the output impedance. You can have 1000's of volts at a node, but its sourced by a VERY high impedance output. so when you touch it with your hands (which is like 100kohm on a dry day), the voltage collapses because of the voltage divider your hand created.
But if the output impedance is low (transmission lines), well its game over.
There's a really good video on this:
https://www.youtube.com/watch?v=BGD-oSwJv3E
But even beyond that, the maximum power output will still be pretty limited. If you short the HV rails, it will almost certainly start to drop in voltage and raise in current quickly, but only to the limits of the resistance from other elements in series and the power source's output ability. I strongly doubt you could even make something dangerous from the Flipper, at least unless you attach a large cap, let it charge slowly, and attach a taser module.
Talking a bit out of my ass here as someone whose EE experience ended at graduation, but a good general rule is if you stay below 5 mA continuous, it is rather difficult to injure yourself. For extremely short shocks (like you get when you discharge a capacitor across yourself) you can get away with a lot more than that, though.
I would be rather surprised if a device that is powered off a lithium ion battery like the one in the Flipper Zero managed to seriously injure someone.
Depends on the specific conditions but less than 2mA for AC should only be a tingle and closer to 5mA for DC will be a slight tingling.
> less than 2mA for AC should only be a tingle
Yep, and even with AC, it depends on the frequency. There are a ton of variables affecting how dangerous electricity is to people, so it's hard to make general statements about it.
Yes. Someone else already did the hard work for us on that. GFCIs commonly trip at 5mA. Pretty hard to really hurt yourself below that.
Current kills. Voltage just makes it possible for the current to get into you.
Chinese Geiger counter kits sometimes include a single piece of plexiglass or nothing at all. I have one I only use when placed inside a plastic bag, so it's not going to be detecting any α. I haven't yet put it up against my CDV-717.
About the same voltage as a carpet shock.
You can get a standalone (cheap) Geiger counter like the GQ GMC-300S on Amazon (B0B541D433) for ~$50. If you're interested in monitoring radiation and have a higher budget to play with, I highly suggest stepping up to the Radiacode 103G (~$600) or the Radeye B20-ER (~$3000). The Radiacode can only detect gamma/x-ray, but is a spectrometer so it can determine the energy level of the radiation. The Radeye can do the full suite of γ α β, and can provide energy-compensated dose rates when its gamma filter is in place.
There are/were Arduino-compatible GM tube kits from China for $35 USD.
There is a subreddit where people measure the radiation given off by random things you'll see them pointing some device at the ground or an object.
Like an old glass cup
If you have one of those small scintillators on you all the time you can measure your own radiation. A significant spike in the spectrum for Potassium-40.
The only thing I can find radioactive enough to be picked up by a cheap GM tube kit is vintage real green uranium glassware. Even a giant bunch of bananas doesn't increase counts enough. Smoke detectors also don't seem to be radioactive enough either.
When I was playing with arduino geiger counter, apart from of course breaking the tube, I struggled with counting the results.
On one hand it's trivial - counts (ticks) per second. However, this (of course!) can be very spiky. I ended up using pretty simple EWMA to smooth the results for user interaction. Anything really works, short decay is fine.
Then the really fun bit, was trying it with more serious radiation source, and guess what.... interrupt per tick, is... really bad! I was easily able to overwhelm the arduino, too many interrupts. Fun project to understand interrupt masking.
I wonder if a device with worse RAM can measure radiation by checking how many of its own bits are being randomly flipped.
Coding a program that could self-heal and survive in such a situation would be fun.
A device with a camera can: https://hackaday.com/2012/01/15/turn-your-camera-phone-into-...
Back in my SIL4 days, we had a de-capped memory SIMM in the lab that we used to test resilience to cosmic rays for certification and other testing procedures .. often requiring a junior dev to sit there waiting for the signal and remove the lead shield we'd place over it when not testing, in order to trigger a cosmic bit shift. We had t-shirts for those guys "Guardian of the Cosmic Bit" printed up, was a fun time ..
You'd crash the hardware just as often as the program.
This is cool, but if you're ever in need of a dope present, especially for someone like your father-in-law, Better Geiger[1] is awesome. My FIL was stoked. Loves checking the bananas at costco and other random stuff at costco.
[1]: https://www.bettergeiger.com/
This reminded me about a wtf moment back in 2008. New York City tried to make it illegal (misdemeanor) to posses a geiger counter without a license. Obviously, it never became law.
https://www.schneier.com/blog/archives/2008/01/locked_fire_b...
I bought a few Geiger tubes about 10 years ago. The larger one is more sensitive, but doesn't detect beta radiation. The smaller one does alpha/beta/gamma, but it's less sensitive. When you buy the tubes, you don't get the benefit of a calibrated measurement device, so I also bought a few Cesium 137 calibration sources. (No idea what sort of government watch lists I ended up on after placing that order.)
Next, I built a simple Geiger counter based upon a Raspberry Pi (Model B) and a Piface LCD display. I wanted to increase dynamic range of the measurements, so I did some circuit modifications to recharge the Geiger tube faster after an event. This allowed for higher counts, but consumes more power and lowers sensitivity. Also, getting the Pi to interrupt on each event for efficient counting has its limitations. A separate digital counter that is reset upon each read sample is better.
Anyway, it's a rabbit hole that ended up taking a lot more time and effort than I expected, but I was happy with the results.
Hypothetically speaking, how useful would something like that be in a nuclear weapon fallout scenario? Can such a contraption detect the important isotopes and give the user an accurate idea of the level of danger they're in, does that change over time as isotope composition changes through decay?
Are you willing to bet your life on it?
No, I'd be dead anyway. Still curious what these things can do, seeing as some people buy them for that purpose.
tl;dr not useful. To make a long story short, max range is very important and these cheap tubes saturate easily, and they don't give energy-corrected dose rate. They also cannot do gamma spec (isotope identification), but that is not needed for a fallout scenario because fallout contains basically every isotope under the sun, no need to do any gamma spec. I have a very long detailed video about this topic on my youtube channel BetterGeiger
I admire their solution to the modulo fair randomness issue is just "re-rolling" the out of scope (7,8,9, or 0) values.
We need the iconic sound of the geiger counter
Really neat. It'd pair well with an alarm the user can set at the appropriate turn back dose for custom doses and concerning dose rates
It's cute, looks nice, and bravo for shipping something, but FZ is too hyped and too expensive for what it is.
I have a similar Geiger counter that functions standalone and works as an Arduino module. It doesn't appear to be very sensitive because bananas don't increase counts. The only household object able to barely increase counts was some vintage uranium glass tucked away in a corner behind a display case.
Is there a maximum level to the measurement? Asking for a friend… “3.6 roentgen. Not great, not terrible.”
I am not certain but this tube looks like an M4011 which typically measures up to 1 mSv/hr for a reference Cs-137 source. Pretty low maximum level, not suitable for emergencies.
Why did I see graphite on the roof?
Do a search for "MightyOhm Geiger Counter Kit Bundle" and you will find a stand alone version of the same circuit along with photos. Although the PCB has a "High Voltage" label, it is powered by 2 X AAA batteries which are might be very lethal if ingested.\s
Powered by 2x AAA batteries != not high voltage. Boost converters can reach high voltages pretty easily. That's why you can get USB powered nixie clocks, for example.
You can shock the hell out of yourself with the capacitors for the flash in a disposable camera, so the AAA battery source isn't exactly exculpatory...
Here it is -
https://mightyohm.com/files/geiger/images/6275026497_3cf9f17...