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How to make a Geiger Counter? Answered

Ok so I just read the book "The Radioactive Boyscout" and I am now interested in making a geiger counter. How would I go about doing this? I mean I am pretty sure gas is used somehow to measure radiation and such but how is it done? It cant be that hard can it? and where and what could I test it on, I was thinking possibly an old radium clock maybe ? HELPZ



6 years ago



7 years ago

Google Kearny fallout meter. The KFM is what it is, nothing more. Just an expedient method for citizens to determine if it's safe to come out of their shelter after a nuclear event. The creator of the KFM, and others say when constructed as direct edit needs no calibration, and is quite accurate. That includes those who have refurbished cold war era CD Geiger counters to sell to you.Probably not the fancy Dan electronic device you are looking for, sorry...


7 years ago

Check Electronic Goldmine. Today's 3/18/2011 email flier had several GM options. They use to have a schematic on their website as well.

I did that and I got nothing!

. I get 8,860 hits. Most on the first page tell you what you want to know. In a nutshell, you place two charged electrodes in a gas that ionizes when irradiated. The amount of current passing through the electrodes is proportional to the amount of ionization/radiation.
. The Wikipedia page is a little weak, but maybe some of the patent links will help.

Ok if there are SOOO many good sites then show me one that gives me an easy circuit diagram and pictures of it being built.

. That's the sound one makes when exhaling sharply with the lips held loosely together. It means, that, unlike westfw, I'm not willing to do all your research for you. . Fourth hit on the list and you're too lazy to look that far? Pfffffffttt

How about that sound when you stick out your tongue? Rssssssssssssssp

. You've been handed enough info on a silver platter that you should be able to build one from scratch. Follow the links that we have provided. If you run into anything you don't understand, ask a question. . You'll need a basic knowledge of electronics. This is not what I would call a good first project.

. I fail to see how any of my comments are underhanded. If there is something that is not plain-as-day, please point it out and I will elaborate.

plain-as-day ?? there's no link for that ?? and all those minuses seem to confuse the search engine <>

How about This one ? (hit number 4 from the google search...)
Conceptually, a Geiger counter is simple; a HV supply connected across a geiger tube, and an amplifier of some kind to amplify the momentary electrical impulses that occur as particles stream through the vacuum of the tube.
I don't believe that I've seen any plans that include making your own geiger tube, although that shouldn't be impossible.

It seems that everyone ignored your question! Simply you need, a GM (Geiger Müller) Tube , they come in various sizes and some are specially designed for specific radiation detection. Alpha, Beta, Gamma,etc. A high voltage supply, between 300 and 700 volts DC, see the Plateau voltage of the tube you use. An amplifier, either/or to amplify the clicks produced when particles pass through the tube and ionise it, or drive an indicator (Meter etc.) to display the rate and level. You will find passable circuits on the net, but perhaps it is better that you know what is needed before you get too deep. Have fun!

Yep, but your not spoonfeeding us yet.... it should be more like this... complete with links Galactic Electronics provide this schematic. And of course places to buy parts from like Digikey and don't forget the hard parts, the Geiger Muller tube this is for cheap surplus ones that may or may not work but who cares about safety your playing with 900 volts here Surplus sales Geiger tubes And if you want a good NEW tube that works, it's tested and calibrated, and wee bit more expensive Canberra They sell tubes to nuclear power plants and the military and other labs ..


helpful yes, spoonfeeding, most certainly... This took me under five minutes with Google... (( Oh except the link to Canberra I did bookmark them about a year or two ago and they do sell new calibrated equipment that meets all regulatory standards)) but does the rest of it work ?? is it some thing your willing to risk your life, health, safety on ?? And when some one does all the research for you and hands it to you, what do you learn ?? PS westfw also linked to the same site as me and some how it got ignored ...

Your probably correct, but some people will ask a question just to find out how helpful others are willing to be. Thats got to do with psychology not with being lazy. As a retired engineer I have had many learners ask for help and my motto has always been, "Help those who are willing to help themselves". But all this is getting away from the original request, its nice to discuss such things but I guess this is the wrong area to do so. Cheers and have a good day

We weren't ignoring him. All of the information you (and Big Bwana, and Nacho, et al.) provided would have been instantly available to Jackillac92 with a simple and obvious search of both Wikipedia and Google.

Compare our reaction to this topic with a very similar one asking about thermoelectric generators. The writer there not only said he had searched Google already, but even had an image and some interpretation of his search results to back it up.

guess - neon discharge light (from tester) connected to voltage little lower than its minimum strike voltage you also need circuit that quickly shuts it down when it strikes

All you need is a resistor, capacitor, small power supply (( 555 timer and a audio input transformer )) and a neon tube, you use the resistor to charge up the cap to just below the ionizing voltage of the neon tube and when it fires from ionizing radiation, the voltage stored in the cap goes into the neon tube and the voltage drops to below the maintaining voltage the neon tube requires and it extinguishes and the resistor starts charging the cap up again getting it ready for the next pulse... To make it respond quickly you just use a smaller cap and lower value resistor.... However with that said, a neon tube will only pick up very high level sources, and it won't do much with off the shelve type sources.... But here is a simple schemaitc that uses a neon tube as a visual indicator of the Geiger-Muller tube ((( Use at your own risk )))


discharge starters for fluorescent lamps often have other gases inside (most glow purple and some blue and yellow) but they have radioactive source inside the lamp so it won't 'fear of darkness' - does not seem good for geiger counter

the lamp is a small Neon indicator lamp, not a starter, which may contain a very small amount of Kr85 and would affect your ability to get an accurate reading (( depending on the type of tube you use the amount of Kr85 and shielding used )) And having said that this schematic while it works, it is almost impossable to see that neon light in the day time or for that matter even in lighted room so you need no fear of the darkness to start with <> and then you can see it blinking with every count...

If you have no fear of darkness, you can set up an experiment to see single photons directly with your eyes. If there's interest, I'll post about it in Physics.

Done! I do see the problem other people have complained about: The topic showed up in my own profile right away, but it isn't out in the main lists yet.

There's some missing data -- I couldn't find an attenuation coefficient for black-dyed LDPE anywhere (yes, I know how to use Google :-). I didn't want to embed a separate experiment on how to measure it, so I arm-waved it away :-)

Interesting....thank you for this...

and more interest ! btw in 'fear of darkness' i meant that some fluorescent starters do fear of darkness. they just dont work. you light on them for a split second with a led flashlight and then they work there is some effect to see when you enter a long and narrow basement room with such starters. switch on the light and hope that none of the lamps strikes on its own. light on the starter of first one with focussed light that the others dont 'see' (very focussed led or laser). then you see the lamps strike one after another with delay like a wave of light bursting into the depths !

That's fascinating! I haven't seen such a thing myself, and I'd be very interested in it. I wonder if the effect has something to do with photoemission causing a breakdown current and discharging a cap, or some such thing. Anyway, if you happen to have a reference, I'd love to read more about it.

what happens here is simpler the starter of fluorescet lamp is a small disharge lamp itself with 2 metal electrodes and some kinda gas filling. when you switch on it gets 110 or 240 V AC on them (thru resistor) to start the discharge you need electrons to leave one of the electrodes and go to the other. the voltage is not enough to pull the eletrons a photon (light) can kick the eletron out of the metal then the voltage pulls it to the other electrode and the discharge begins. the discharge makes light (more photons) itself so all it needs to start is that 1st photon thats why it waits in darkness doing nothing until you 'rescue' it with a led etc when one lamp is started the basement is lit and all lamps begin to get photons. the one next to the started lamp gets more photons than the more distant ones and is the most likely to be the next most modern starters have inside some radioactive stuff that makes constant 'noise' inside the starter. electrons get kicked all the time and no external light is needed

Haha, someone loves that answer. It's true though. That's how I find out most stuff.

There you go Nacho, you now have every reason to create an Instructable on "How to Effectively Search Using Googleetc ;-)

. I don't think you can teach someone how to use search engines (other than pointing out quotes, +, and -). From what I've been able to figure out, all it requires is a decent vocabulary (so you can substitute synonyms) and a willingness to actually type something in the search box.
. For this particular case, there's nothing I can do about laziness.

True, but there are "methods that work better then others". One person looks, and finds nothing or nearly nothing, and the next one finds what it needed, and the methodology is the factor. Ok, let me think about it then... :-)

. hmmmm I've never sat and analyzed the method behind my search madness.
. Just off the top of my head, it goes something like:
  • think of a word or short phrase that accurately describes what I'm looking for
  • If too many bad hits, I start adding +/- words/phrases
  • If no good hits, try a synonym
. Google will spot most misspellings for me. :)
. I've been surprised at how well typing in a natural language question works. Eg, " how do I test transistors "

Hmmm. I usually use the opposite approach, I generally try not to form queries, but search for phrases that might logically appear in an article on how to do it or why/when where X happened (like in the example you use, testing transistors) instead.

Yep, and since most punctuation and smaller common words are ignored most of the time, I even exclude them

Well for instance, I have been looking for a circuit schematic I had years ago, that showed a relatively simple application towards testing which poles were which on a working transistor. I found many of the ones you have in your search, but not what I wanted. When I specified the type of test, it showed me nothing. Normally I am pretty good at finding stuff on the web...sometimes not so much

the biggest problem I have with transistors is, looking them up on line can give various answers as to pin configuration. A handy little tester to help figure them out would be great (it can be done with a VOM even if no hfe transistor tester is on the meter, but it gets tedious, especially if you don't have clips for the probe tips.

I used to get annoyed with that to, but onsemi answered all my transistor issues, and I just order a sample of the one on the data sheet I'm looking at, so I know which pin is which...

I even started to find different pin configurations for some common dual op amp ICs and thing...depending on the manufacturer.....drives me up the wall.