Buying a cheap geiger counter, worth the money? - Page 1
Forum section: electronics / general

author: ESXi
author_rank: Regular Contributor
timestamp: January 10, 2019, 12:02:08 pm
content: Hi,I was thinking of buying a geiger counter, a cheap one just for fun and experiments at home. What do you guys think about those two devices?OOTDTY BR-6 (old version)OOTDTY BR-9B (upgraded version)Image:(both have a microusb port on the rightside)Any good? Or not worth my ~60 dollars?I can't find any pictures on Google in a quick hurry of how the inside the pcb and GM tube look like. I would like to check that about, and if I buy the BR-9B version add a bigger rechargeable lithium battery (probably one from a smartphone) and a super small buck converter (device needs 3,6v, or a 3.6v linear voltage regulator? I think this is better) because it seems the usb port that is already in the device can also be used to power the device, great !No need for three AA 1.2v rechargeable battaries.

author: coppercone2
author_rank: Super Contributor
timestamp: January 10, 2019, 12:33:55 pm
content: a very cheap solution is to get one of those small high-rad tubes on ebay from the Ukraine for about 6$. I managed to get an output out of it with a small gamma source and a old HV-linear lab power supplyIf you are actually doing experiments it might make more sense to get yourself a high voltage variable power supply and a bare tube.I even managed to over-voltage my tube during experiments to get visible arc discharge from radiation (though this likely damaged it).If you just want to learn about the interface electronics I would suggest you go for a HVPSU and a bare tube and build it yourself so you can get an idea of what changing bias does etc. I like the old keithley vacuum tube supplies.Keep in mind though, they are earthground referenced by design. I guess they are scared to float it.If you manage to find one for <100$ on ebay that is. I don't see any right now. I think I got a broken 1200V keithley reference supply for like 50$ and fixed it up with 12$ of tube replacements. Adding in a 7$ tube it came out less then the commercial solution, so long you don't mind using a scope.Then in the future you have the supply and can use photomultipliers and more advanced tubes.Keep in mind you want money for1) radiations source of different type2) fixtures (even wooden stuff designed to hold attenautors, detectors and samples and move them around on screw threads or such for precise distance control is fairly time consuming, interesting and professional.3) shielding (i.e. a project could be to make standard size lead, wood, steel, etc shields of various thicknesses and dimensions to interface with your tube). You can actually buy old 'radiation attenuators' which are basically measured disks made of various materials used to calibrate equipment, i.e. if your source is too strong and full-scales the range, you put a radiation shield between the source and the detector to attenuate it by a known amount.4) nice storage boxes that are safe to keep (custom casting a lead shield that tightly holds your sample in a nice wooden box comes out a bit pricey if you factor in things like hinges, good quality wood, wood/lead working tools).Without these things I don't think you will be doing serious radiation experiments.Having a high voltage adjustable power supply not only opens the door to various tubes, photomultipliers (with crystal detectors) but also alpha particle detectors, which operate in free air and are shop buildable :https://carlwillis.wordpress.com/2011/09/17/a-simple-spark-detector-for-alpha-particles/by fixture I mean so you avoid what that guy is doing, holding a radioactive source in his hands over a 8000V energized conductor. A nice fixture would slowly bring the sample towards the detector on a screw. And you would wanna put a ruler on it too.And for serious testing, like determining if you have radioactive metal for your own safety, if you are scrapping for instance, I would not recommend using low cost chinese electronics.As a side note, my 300$ Belgian made radon detector broke after about a year with firmware curruption errors. I don't trust these little 'gadgets' very much. Get something with a metal box for the electronics. I did however loan it to someone for a long period of time (something like 1 year measurements), they possibly mistreated it some how. Cannot verify but I would not spend much on portable stuff unless its really old/military spec.

author: Gr8fulFox
author_rank: Newbie
timestamp: January 10, 2019, 01:09:10 pm
content: Quote from: coppercone2 on January 10, 2019, 12:33:55 pmYou read my mind! I thought about making my own Geiger counter, once, and was amazed at just how cheap those tubes are on ebay.

author: coppercone2
author_rank: Super Contributor
timestamp: January 10, 2019, 01:34:30 pm
content: keep in mind those small cheapest tubes are meant for like, the post nuclear battlefield, they are not very sensitive. Look at the spec when you buy them.They won't get many counts per minute for background. I am not saying the more sensitive ones are too much more expensive, but thebottom dollarones are pretty much meant for getting through europe after WW3but they are robust, I made one glow like an incandescent by accident with way too high a bias voltage and it seemed to still respond normally afterwards. Great for the first project where you might abuse it. For 7$.It's also kind of cool because you can make a ultra-primitive geiger counter where you actually look visually for arcing in the tube rather then having to depend on a expensive machine to do it for you. Great for demonstrations. I think it was made that way to survive EMP and allow people to cobble up useful stuff after the worst happens. I have a feeling you can make a useful safety equipment just with the tube and a HV battery (and possibly a voltage divider if you are fancy)(a battery which you took out of the east-bloc radioactive zombie soldiers night vision goggles after a tank squashed your detector circuit)

author: jimdeane
author_rank: Regular Contributor
timestamp: January 10, 2019, 07:22:15 pm
content: I haven't looked at that manufacturer's models, but I just purchased a GQ GMC-320 v5 Plus as a home and teaching geiger counter. It's beta/gamma/x, no alpha sensitivity (glass wall tube), but it can get the job done. It has wifi ability, so I can stream readings to online radiation monitoring sites if I want to.

author: cdev
author_rank: Super Contributor
timestamp: January 11, 2019, 03:44:01 am
content: A friend bought two geiger counter kits from that company that also sells lots of other parts and grab bags and generally has good deals there, anyway neither worked and she seemed to think that the tubes they sent her had some kind of issue.She is actually a pretty electronics literate person and so is her hubby.They ended up with a professional grade survey meter and like having it as its super sensitive. It can also pick up alpha and beta particles.

author: jesuscf
author_rank: Frequent Contributor
timestamp: January 11, 2019, 05:09:59 am
content: I bought a GMC-320 plus a couple of years ago. Lots of fun looking for "hot" stuff. So far obtained decent results with Potassium Chloride from the grocery store, a 5% (I think) thorium welding rod, and "depression" glass. But by far the must fun is taking it into flights and see how the count rapidly climbs as the airplane gains altitude...

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 11, 2019, 06:45:52 am
content: These ones are the cheapest ones I found. I think the last one on page 2 is good.http://www.cfcbazar.com/?s=geiger+counter

author: ESXi
author_rank: Regular Contributor
timestamp: January 18, 2019, 10:21:37 am
content: Quote from: nsrmagazin on January 11, 2019, 06:45:52 amThanks. I have seen a few of them on Ali and Google. I like the website it sums them all up.I came across this one and according to the Chinese specs it wasn't any better than the than the cheapest AIO one listed on Ali (see 1# v2).http://www.cfcbazar.com/products/em-portable-handle-geiger-counter-assembled-diy-nuclear-radiation-detector-with-miller-gm-tube-gamma-beta-ray-suit-for-arduino/@everyone in this topic.So what you guys tell me is that I should build my own Geiger counter for better precision?It doesn't have to be a professional tool, I just want to play with it. But if the cheap device it's readings are all over the place it is not fun either..A cheap oled screen a library for arduino or my first pcb design is also something I want to do. Still wanting to do double buffering for mygps speedometer toy, but been busy, been searching for a gearbox sensor for my old vw 3 car and a speedometer but they all have a tachometer and mine doesn't have one so which means other cable hardness etc. So I guess I will have to update my gps speedometer toy, add double buffering and fix the slow gps fix issue and use that thing instead because second hand parts are harder to come by.Sorry for the delayed reply, been busy all week.

author: cdev
author_rank: Super Contributor
timestamp: January 18, 2019, 02:36:20 pm
content: A Geiger counter is supposed to offer a very good source of true randomness, for what its worth.Although not a super lot of it "bits" wise.

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 19, 2019, 09:02:30 am
content: The sitehttp://www.cfcbazar.comis actually an AliExpress affiliate. They pick the sellers and products from AliExpress by their standards and provide any assistance they can. For example on the site they offer to find the product for you also for any questions you can always send them an email. They reply rather quick(a bit time-zone dependent though).You are probably right about the geiger counter's randomness, I also think so but I have never confirmed it.

author: ESXi
author_rank: Regular Contributor
timestamp: January 21, 2019, 12:38:55 pm
content: Quote from: cdev on January 18, 2019, 02:36:20 pmThat's right. The noise is always present, it's background radiation.About the GM tube I don't know which one to buy, A Russian NOS SBM-20 seems to do about the same as a cheap one made by North Optic and put into all those cheap gadgets.Those only do beta and gamma [β, γ].https://www.cooking-hacks.com/documentation/tutorials/geiger-counter-radiation-sensor-board-arduino-raspberry-pi-tutorial

author: rdl
author_rank: Super Contributor
timestamp: January 21, 2019, 01:30:25 pm
content: I was thinking about buying a geiger counter a while back, still am actually. These people sell geiger counters and have useful info on their site.https://www.imagesco.com/geiger/buying-a-geiger-counter-pg1.htmlNo, I am not affiliated with them company in any way.