Just a plain silicon photodiode alone would probably be more sensitive than this contraption... A student of mine built a quite capable gamma spectrometer this way.
Making this video has given an impression that the world actually needs something like the NukAlert, but one that works for real and delivers some useful data. Perhaps we will develop one ourselves...
@project-326 something aimed at the Prep's market sounds like a great idea. IMO, it needs to be practical, affordable, and most importantly - to legitimately work!
@@Nachos-sk7od This is correct for alphas and betas. For gammas, the cross-section is too small to be sensitive enough. A scintillator is much more efficient.
I agree. I wanted to keep the cost of the system under $10, but the cheapest scintillator I could get is a recycled CsI crystal from a medical X-ray machine, for $6 each (4*4*3mm). I'll test it to see if it improves gamma sensitivity:)
If a safety device for any other field had the same rating, it would not be allowed on the market. Yet it sales for an outrageous amount of money because most of the public is usually not familiar with the mystery of radiation and greed rushes in to fill in the gap. Great work my friend! Keep up the good work !
lol it just clicks rhythmically like a metronome. Let alone the fact that it just pretends to work, how dumb must the developer be to not use at least some form of entropy to fake it
Very detailed video, I was always interested in what was in it, but it was too expensive to look it up myself :) And it's great that you only used the usual voice again. ^^
Yes, the voice, that's a whole thing... Damned if you do, damned if you don't. Myself and Max (yes, it really is another person), are actually thinking a bit about how to make it a bit more of a double-act, there are quite a lot of interesting options and interplay for doing that in our 'idea tank'. Let's see how things work out.
Very interesting! I thought that this device was legit because BNC was selling it, glad I watched the video. Not that I would have gotten one anyways since I have more suitable equipment, but still.
The cheapest detector i have is a "Hakarucchi ipt'a" which i got for less than 30$ shipped in 2014. The "RAT-1W" is the same probably with other look. These where sold after fukushima. They are no longer available, take 3 AAA batteries and have a single button and simple display. They can display average radiation of the last 1-6min (0.1ySv/h - 19.9ySv/h) and lifetime dosage. Mine remembers the lifetime value without batteries since many years. Also shows around 0.1 for background and 2.3 for a old camera lense with thorium, next to it after a few minutes. Considering the inflation since 2014 and that this included shipping, thats quite cheap. Mine has a blue label with a picture of playing children and butterflies on it. I think these where made in japan without any intend to make a profit but rather help people after fukushima. Iam not 100% sure what detector it uses but i think its some semiconductor detector.
I do not know about the rest of the world, but in Russia the Internet is littered with ads for the sale of old Soviet radiation measuring devices. Army devices can be purchased from $ 10 ($10 for a workable device!). A normal household appliance will cost from $ 30.
eBay has a lot of this stuff too, but not as low cost as you describe. The detectors that military personnel were issued had a very different purpose to what the general population needs. They were designed to assist military gauge the 'correct' time to come out of cover and attack the opposing lines. Too early and your guys will have a very short time to live, too late and perhaps the enemy has already overrun your lines. They were not designed to keep people safe, they were designed for front-line troops to win a battle so that reserves can then later come forward and repeat the process.
Thanks so much for another interesting and humourous video. In my opinion Posh Arthur is all this channel needs so Max can take a well deserved rest if he feels he has other things that are more important. As a result of your reviews I have bought a Little Garden Spectrometer...arrived very quickly in New Zealand as did a Bosean Detector. Both great and fascinating products. I just wish the Bosean light flashed together with the clicks as my other one does, an Aware Electronics RM-60 and LCD-90Pro logger, but that is a small omission for the price. Keep up the good work for us all!
I'm glad that you managed to find a couple of bargain products that actually work, its a feeling that we all enjoy, finding low cost gems... From my perspective, having bought so much dross, I'm just pleased that the Bosean actually has clicks!
Great review, I made more sophisticated electronic devices when I was in high school (late 1980s) with parts I bought at Radio Shack. Definitely a scam, IMO. At least 10x overpriced and overhyped.
14:21 I thought you were going to smash it with a hammer xD It only detects fluorescence with a photoresistor, so it needs extreme amount of radiation to work. A total scam. lol I like the robotic voice
Hello. Dude on this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-XbAV6qaor38.html showing many dosimetrs going off the charts. But u have use translated subtitles
Where in hell did you found a 2n4117? All FETs I bought were bipolar transistors rebranded as FETs, meaning fake ones. The only ones I found were SMD from Interfet and the old ones I have in my junk box.
Thanks for the comment. I have seen dodgy little resellers (usually they operate out of sheds in the countryside and keep moving around to avoid getting busted) re-marking cheaper components for more expensive ones, but for cheap transistors, that's pretty slim pickings. These days, those little fake component vendors are dying out - they would have completely died out if it wasn't for the Ukraine war. I heard that these remarking shops are now busy selling fake MCUs to Russia. Maybe its a coincidence, but the VKD has lost quite a few war-planes recently due to 'technical faults'. I know quite a bit about these re-marking operations. My wife comes from the same rural part of Guangdong province where this is (or was) quite prevalent. I also work with a lot of factories here and they tell me a lot of stories about this and how they avoid getting screwed on component supply. I got these JFETs on TaoBao. China has a lot of discrete semi manufacturing, though its aimed at the internal market. I have found all kinds of things here that seem to have died out in the west, diac triggers, uni-junction transistors, etc. A funny story about the uni-junction transistors, a friend of mine in the UK was looking for some as part of a relaxation oscillator, but in the end, it was just a bit cheaper to get a Chinese 8 pin MCU (8051 clone) and create the same signal via PWM (a 13 cent MCU)... Mind you, the 4117 isn't particularly special, most n-ch JFETs will work in this application. There is no HF gain requirements, the Vgs is fairly typical. Perhaps the ones I got are a different type, but they are certainly JFETs, and for this near-DC application, it probably doesn't matter. I think I paid 7 cents each for them (for a strip of 10 pieces).
@@project-326 I really don't know why FETs died out. Some say they were not trustable. But they are more resistant to static, to radiation and much lower thermal noise than MOSFETS. Certainly there are applications where they are preferred (hearing aid devices are one of those, maybe that is because I can only find them in SMD form). UJTs I can still find easily here.
The PIC12F5xx series are the absolute cheapest of PIC chips. They are great for small simple jobs and I've used them for many projects because they cost $0.60 each. The CDS cell is also the cheapest possible sensor and even a simple photodiode alone would probably do a better job. I'd even wager that a 1N914 signal diode might be more sensitive and cost less. I'd love to download the firmware of the chip and disassemble it for shits and giggles. I suspect it will grossly under utilize the capabilities of these PIC chips
Great video as always. Thanks for sharing! For such a price, I thought they'd use SBM-21 for the sensor to achieve the small size and sensitivity. Then a minute down the test part, I'm totally angry about how terrible it is. In comparison, the ionization chamber without special treated gas but filled with merely air works better than I expected!🤯
I was really surprised with how it worked detecting x-rays. It could detect a decent alpha source like Am-241 but was useless with my other sources. With the x-rays it was just amazing!
Our approach to product reviews means that in almost all cases, we need to go out and buy products to test which get expensive. Most manufacturers won't send us a sample of their equipment to test, they are usually just too scarred to do so, or don't have enough confidence in their products.
Don't worry, the GS has more features, so has many more ways to disappoint us. It's pretty hard to poke fun at something with the functionality of a paperweight.
What happens if you leave the source on the detector for a longer? Period does it pick it up? It might require more time to react with simple electronics.
I am surprised that this has good reviews on Amazon. Just shows these people don't test their products or it is just another case of Amazon pushing scams.
How would anyone know if it works or not, unless they can convince a friendly dentist or doctor to help them... I saw loads of reviews that said it went off in situation X or Y but I think those are related to sunlight getting into the unit.
The huge markup is not as infuriating as the fact that this is just a crude X-ray detector and nothing else. Big thanks for exposing this piece of garbage.
@project-326 they used every trick in the book to ensure that sense of security. I'm surprised that FCC and CE have not caught up with this scam. Hopefully, your work will raise some alarm bells.
@@duke_of_oz Normally the FCC and CE won't intervene, they don't want to use the resources. Well, unless it is a Chinese product, in which case there will be customs seizures and a "SWAT team" type response... The Gamma Scout doesn't have FCC certification either and that has been available in the USA for decades.
Yup. The gadox has zero response to anything north of about 200keV, no response to alpha or gamma. Using a CdS cell is making a bad product even worse.😢
@project-326 since you already have it try replacing the CdS cell with a J fet and photodiode. Then put a LYSO crystal in it. Should make it a lot more sensitive, at least able to respond to the Sr90 and 137Cs check disk.
great check, I have toght it use diode semiconductor and sense over beta. It would make sense for a cheap device, but it is actually not cheap at all. As the mica window at my inspector Geiger mueller pancake tube has broken and never found a cause, maybe due to the travel over mountain and air pressure change or even manufacturing defect. Besides the replacement from the LND the decision was also to get one rugged LND 71210 for the safety situation. In the case of explosion the blast pressure may destroy mica and make it useless, so the cylindric tube that use more rugged window may be more reliable. It is also energy compensated so may be used for better measurement of some sources. For the same reason it was expected that nuke alert use diode rather then mica. Tested and LND 71210 performs quite fine on the same GM made for their pancake tube, just the calibration is different. Sensitivity of ion chambers is lower then GM, but they have great linearity so they are good for measurement.
Thanks for the feedback. Those kinds of alpha capable GM tubes are very fragile... The proportional region of the curve is certainly much better for linearity and can even be used for spectroscopy, etc but has really terrible detection sensitivity... We are actually considering creating a DIY device that is small like the NukAlert but actually works...
@@project-326 scintillators may be fine solution, but they are expensive, so diode appears as an acceptable solution for high contamination. But the main purpose of such detector is when to get out of the shelter and where to move, as the initial blast does not need detector.
If it is that bad, I need one of the other dosimeters. Because I bought one over 20 years ago, I have had to put it in a drawer because my window is under the house waves and it would click so loudly after it rained in 2011 post 3/11 I had to put it in a drawer. The only time it actually made an alarm was riding with my brother on the interstate when he was trying to pass a white unmarked tractor trailer, and I pulled it out of my pocket and showed him, convinced him to slow down and exit to travel on another highway to get away from that truck. Other people carrying a Geiger counter because of 3/11 were having similar experiments on interstates encountering white unmarked tractor trailers. Apparently thefind it safer to move hot loads with no marking or fanfare ?
Thanks for sharing your story. The stray gamma radiation from nukes being transported certainly would not set the NukAlert off. I have read a lot of reviews that talk about it being triggered by sunlight, power lines, etc. In a nuclear warhead, there are only three types of radioactive materials, Pu-239, U-235 and in older devices, H-3. The first 2 are alpha emitters and tritium is a beta emitter. Without expensive specialist detectors you would have trouble detecting any of those, even at short range (weapons grade material is very pure and so there won't be anything much in the way of decay products that are more detectable). Natural uranium ore is very detectable with low cost equipment (but not with the NukAlert) because it is billions of years old and has a lot of decay products contained in it. Look on the bright side, I spent a lot more to test this PoS that you did 20 years ago when you bought it, which makes me the sucker! In addition to buying it, I needed to pay for shipping to China, importation duty, the x-ray source, when when added up comes to about $450... In fairness, due to its small size, its a great addition to a "hall of shame". Its got a cool form factor and a great sales story behind it. The exact properties that we all should be cautious of when buying new things.
@@davehimlin2374 There is no need for such functionality as the environment radiates enough particles for a detector to tick, and thus let itself known to the user that it is on.
In your opinion what would be the minimum microseiverts per hour, needed to casue this unit to start chirping its alarm ? Is this device completely useless in a fallout situation, to alert someone to get to a shelter before they would be in mortal danger of over exposure to nuclear fallout/radiation ? I also want to thank you for spending so much of your time and money on your videos.
Thank you for your comment. I really don't think that there is a minimum, better sensitivity is just better. With more sensitivity, you can avoid moving into dangerous areas, ie get a warning BEFORE going into a dangerous situation. The most basic issue with this device isn't the raw sensitivity, it is what it is sensitive to, it will trigger with a dose rate of about 2mSv/h of x-rays, but for gamma rays that you might expect from fallout, the required dose rates for triggering is far, far higher. Anyway, thanks for suggesting this video.
@@project-326 Ty for the response. We must also consider that even though it does work under a XRAY , the radiation from such a device is 2-10 milliseiverts deliver within in a second or less of time. For the sake of argument, lets jsut assume it is 5 milliseiverts deliver at 1 second interval which sets off the alarm on this device. That would be equivlelnt to 300 milliseverts per minute or 18,000 millseverts per hour which is 1800 REM per hour ? If my math is correct that is considered 4-5 times a lethal dose ?
@@davehimlin2374 Sadly, yes, you math is sort of correct, well sad for anyone that thinks this device is going to be useful to them in the event of the unthinkable... Rads is probably a better unit for this model as Sv or REM make assumptions about the effects on the human body. Thanks for reaching out!
@@project-326 I agree...I think it would be nice for families with kids to watch this channel together. It could be very educational for interested science minded children.
@@alastairbrickell8813 We are considering starting a new channel, just for experiments for kids, but a little less patronizing and dumbed down as the other 'kids science channels'.
The GammaScout most likely has a gas tube in it while the others have a scintillator crystal. Under high flux the tube don't work properly as a continiously conductive path exists and it stops counting. Not good but expected behavior.
Actually, in the testing section, the BR6, HFS-10, HTT-60 and FS-5000 are also GM tube devices. Typically with a GM tube, once the count rate gets too high, the dead-time limits the count rate to a pretty fixed maximum. To become continuously conducting, the tube voltage needs to be increased, taking outside of the Geiger plateau region and into the continuous discharge region. We have a separate review video on the Gamma Scout, it is a device that we have a long history with and features in many of the review videos...
@@faxezu Whilst this is a sort of educational channel, we try to have fun too. The Gamma Scout is just a badly designed device, the company that makes it, has a real dislike of this channel, every now and then one of their people shows up in the comments on a hate-fest. We have pretty much figured out who their small team in Germany are now and what Google accounts they use. Will probably have to go through the process again with the people behind this horrid NukAlert... It strange, there are a lot of videos featuring it, but only with a view to selling it. Well, there is a full review on the product now! 🙂
@@project-326 I might be German, but I swear to have no affiliations to GammaScout 😄 Thanks for the nice video and sorry again if my first comment sounded negative!
The original Russian one was decent. It dis more or less the same thing and the battery could be changed. A 10uCi check disk would get it to beep and was loud enough to easily hear it. It was only for detecting dangerous levels of radioactivity and also was only 25 bucks😂 180 bucks could get a decent geiger counter.
17:50 min: An addition to your statement that gadolinium oxysulfide is 3000 times less sensitive to Cs-137 than to X-rays and has a shockingly low sensitivity to gamma radiation. If you read the patent US6897448, the sensor consists of 4 components: a transparent cone, 2 layers of phosphor and on top (outside) a high-density metal coating. The author recommends lead. It could therefore be that the sensor is surrounded by a thin lead foil and only the bremsstrahlung generated in it reaches the phosphor and interacts with it. It is then also sensitive to this. That would explain why your first X-ray tube had no effect; the lead completely shielded the low-energy radiation. It could therefore be that the sensor is more sensitive to radiation that generates a lot of bremsstrahlung.
The product data sheet also states that the newer versions don't have the lead foil added. Besides, photons don't generate bremstrahlung, only particles (ie things with mass) can do that. The other point is that bremstrahlung is a very small effect compared to the original flux of beta's or other particles that give rise to it, ie the efficiency is very low. A typical x-ray tube, which is about as an efficient bremstrahlung source as it is possible to create (ie vacuum, high density target, etc) has a typical energy efficiency less than 1%. For incidental bremstrahlung, you can expect the efficiency to be somewhere between 0.1 and 0.001%. I hope that helps.
Thank you very much, this little channel appreciates all the help it can get! Perhaps you can give help me with deciding what the next video should be, I have some options: 1) Part #3 of the 'UV Vs GM' video, I have more than 10 videos from other people that can be woven into the final part of that subject. 2) Testing, teardown and analysis of a laser power meter that I recently acquired. 3) Some beta particle experiments that we have done, including using magnets to deflect them. 4) The Faraday effect, how we built that experiments and the results. Your feedback would be greatly appreciated.
Doesn't seem like a true scam. At least the design technically functions as a radiation detector. I'm sure there was a much better design someone made but the accounting department demanded that they cheapify it.
The creator of the NukAlert was a one man team, I believe he took on some staff and uses sales agents, but that isn't the same thing as internal company pressure. I get the feeling that this was the only design he created, the company only has one product and has been selling the hell out of it for over 20 years. You are right, it functions just enough to avoid a class action. Thanks for the feedback!
Always satisfied 😀 my curiosity with your comprehensive video..........please do a video on construction of the ionisation detector shown here ..... will be a fun weekend DIY project for viewers !!!!
perhaps, but there are already a lot of videos on this type of thing on RU-vid. We do prefer to have unique content, that said, even when we have the ONLY video on something we came up with, it doesn't seem to get a lot of views. The beta backscattering video and the IR chroma keying camera video both did poorly on RU-vid, both of which are totally unique.
I appreciate you took it apart and told us about its design, however, I disagree with many points in the video. Why not buy a cheap Geiger counter instead? Well, because under nuclear attack it would be useless, it can behave as Gamma Scout did or show zero. Even if it didn't, what is it good for when it tells you you have gone beyond 10mR/h? Surface bursts create fallout plumes where radiation field reaches hundreds of R/h. I'm talking about gamma only, during the "acute phase" it doesn't make much sense to care about beta other than keeping fallout particles away from your skin and preveting their inhalation when fallout descends, there are almost no dosimeters that show you beta dose rate (all those who "measure" beta with their Geiger counters and gamma scintillators do it wrong). Cheap Geiger counters are often gamma non-compensated and not even beta shielded, so they show nonsense values in mixed radiation field, another reason why relying on them only is a bad idea. Geiger counter with range up to 10-100mR/h may be useful inside a fallout shelter. By the way, deposited radioactive fallout is a plane source, removing some contamination from the shelter won't save you from radiation sickness, it's proper shielding that does. Civil defense protective measures were designed to prevent people from suffering acute effects of radiation exposure such as radiation burns and sickness, those short lived isotopes which you mentioned as not important are actually those that matter the most, during the first day or two their gamma radiation delivers the greatest portion of the total dose. As they decay fast, they have very high specific activity. Cs-137 won't be an acute hazard. When it becomes the major contributor to gamma dose rate (about 4 years after the explosion), there will be no areas of immediate danger, maybe except the very epicentres of surface bursts. By that time Nukalert may be almost useless. Of course it doesn't mean you can't use Cs-137 for the purpose of Nukalert validation, you just have to use a source strong enough to create that R/h range gamma field. In my opinion telling people that Nukalert is useless and that they should buy a low range Geiger counter is dangerous. If the Nukalert scintillator responds mainly to X-rays, there is a remedy for that - energy compensation and the patent mentions that. Not only the layer of lead attenuates low energy radiation (preventing falsely high readings), when high energy photons come, they liberate electrons leading to stronger response. X-ray testing you have shown may be good to test if it can respond to radiation but without further data (spectrum of the X-ray source, energy characteristics of the detector - after compensation!) and calculations it can't be used for indicated value verification.
I wonder what caused it to chirp such a long time after the X-ray burst, maybe the burst was so intense that it damaged the detector and/or the electronics.
That's the way is it 'supposed' to work, according to the patent and the product documentation. The MCU flashes the LED to [allegedly] make the phospher more sensitive, which triggers the LDR, which in turn causes the MCU to flash the LED. They do this to make it have some sensitivity. So, this ends up with a system that has a crazy long time constant when triggered.
Thank you for the long and well thought out comment. One thing I learned, when talking to people in the prepper movement, is that everyone seems to have a slightly different view on what a nuclear exchange would look like. Expectations vary from "the government will be back up and running in a month or so" to "back to the stone age", and this has a lot of effect on the use case. I fully agree, short half-life products are more dangerous, far more so, but if you are going to stay holed up in a 'bunker' (ie use case is important) for a month or more, then actually it is the medium term fission products that will become more relevant to long term survival. In any cases, the simple fact that the NukAlert is almost totally insensitive to gamma above 100 KeV, means that even very high dose rate fall out will not be detected by this thing. The Gd2O2S scintillation material has almost no sensitivity at the important gamma energy levels. The manufacturer is well aware of the failings of this device, what is important to them is sales, not functionality. What I would caution over is comparing devices intended for civilian use and those that were created for military use. Cold war military doctrine, on both sides was not something that produced equipment that would be helpful to civilians. In the cold war, the expectation was that soldiers would take cover in preassigned locations. The side that sent its soldiers out at the "right" time would win the battle. Come out too early and the soldiers will be incapacitated very quickly, come out too late and the enemy has already over run your positions. These types of calculations were not factoring in long term health of the soldiers...
I haven't tested it but I saw another review and it seems this device is using pretty horrible HH71x tube. Basically they have taken all the cheap options from the GC-01 and rolled it into an even crappier product.
