SparkFun Electronics - Geiger Counter

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Product Info

Geiger Counter

sku: SEN-09298

Description: This is a USB powered Geiger Counter equipped with an ATMega168 that can be programmed in circuit using one of the programmers below. Simply plug the unit into USB (make sure you have FTDI drivers installed), open a terminal program to the correct COM power at 9600bps, and you will see random bits being generated from the random background radiation. Here at SparkFun, on average, we get about 20 counts a minute.

Check out the random number generating Geiger counter tutorial for more information.

ATTENTION: While the Geiger counter is powered and the switch is in the ON position, the board contains exposed high voltage components. In order to turn the unit off, you must flip the tube power switch to OFF while the USB cable is plugged in or while the board is still connected to your power supply. The reason being; when you move the switch into the OFF position, the high voltage lines are bled out through a resistor connected to ground, more information on this is in the tutorial.

A project box or enclosure is suggested. Do not touch the end window of the Geiger tube and do not to touch any conductive region inside the area marked HIGH VOLTAGE when the Geiger tube is powered ON. An enclosure is not absolutely necessary, but if you choose not use an enclosure, remember to be extra careful with the end window and high voltage regions.

The Geiger tube comes with a red boot to protect the end window during, production, handling, and shipping. The boot should be removed if you are needing to detect alpha particles. However, you should still see activity from gamma and beta particles even with the boot on.

For older revisions with a bleed button: Remember to always hit the bleed button with your power supply connected, after the tube power switch is moved from the ON position to the OFF position.

Features:

5V@30mA input
LND712 Geiger tube
ATMega168
FTDI USB
Power and status LEDs
TTL output pin from tube

Dimensions: 4.15"x1.75"x1" (without standoffs)

Documents:

Schematic
Example random number generator C code

Pricing

	8 in stock backorder allowed

$149.95	price
$134.95	10-99 (10% off)
$119.96	100+ (20% off)

	quantity

click on image to enlarge

Comments

17 comments

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	by nagmier +1.6 \| October 20, 2009 at 3:33 PM 0
Holy Cow! Awesome! I want one! :)

GlennPowers

+2.7

| October 20, 2009 at 10:06 PM

+0.21

Placing the Geiger tube inside a case will make it mostly insensitive to alpha radiation and inhibit beta radiation. If you cut a hole for the front face of the Geiger tube, it's dandy. But, it's not omnidirectional for alpha and beta.

You'll want to get a radiation source to increase the number of readings. I recommend United Nuclear:
https://unitednuclear.com/index.php?main_page=index&cPath=2_5

This Geiger tube is well suited to have an isotope disk source placed directly in front of it's detection window. But, beware of maximum detection rates.

Also, Nuclear Safety for kids:
http://meaning.com/wiki/Image:Ghosted-eliz-cs-137.JPG

	by Mitch +1.2 \| October 20, 2009 at 10:24 PM 0
Now where can I get a little electronic clicker that sounds like a classic geiger counter to attach to this?

	by TheMoogle +6.5 \| October 21, 2009 at 4:39 PM 0
Are there any plans to sell this without the tube? I have 15 tubes already that I would like to use :)

	by BT +15 \| October 21, 2009 at 7:51 PM 0
One of those Coleman gas lantern mantles should have enough thorium to give a lively count rate...

	by BT +15 \| October 21, 2009 at 7:57 PM 0
Oh yeah, you seem to have a 47pf resistor in the schematic...!

	by BT +15 \| October 21, 2009 at 8:03 PM 0
And shouldn't the transformer secondary be grounded?

Manuel

+1.2

| October 22, 2009 at 8:36 AM

If you attach an electromagnet on the side of the geiger muller tube and have the radioactive source between the tube and the electromagnet, you can, by varying the magnetic field (from small to big preferably), do a beta spectroscopy. Depending on the magnetic field intensity, different energy particles will go in an half circle trajectory around the electromagnet and hit the geiger counter. Thus, by counting a time T for each energy level, you can get the specter of your source and thus, analyze what the radioactive source is. A geiger tube like this will only tell you if there are beta particles present (electrons or positrons). Also, beta particles shouldn't be harmful to the human body, gamma particles are the ones I would fear.

kofs

+2.3

| October 24, 2009 at 5:44 PM

A few guys in the comments over at hack a day have expressed concern over an alleged lack of isolation between high voltage and data lines in an article on your new geiger counter. http://hackaday.com/2009/10/21/hackable-geiger-counter/

I do not have the expertise necessary to know whether they're right or not but if they aren't (or are) you might want to comment on the article yourself! There is plenty of praise in the comments, too.

A1ronzo

| October 26, 2009 at 10:56 AM

Thanks for the great feedback!

Opto-isolating the high voltage from digital line is a great idea and we will take that design suggestion into consideration for the next rev.

However, the current design works great and I have been using my 1st proto since earlier this year without problems. Isolating the high voltage from the digital might not be completely necessary when you take extra precaution with physically isolating the digital line from high voltage lines.

Your suggestions are greatly appreciated, keep 'em comin!

	by Fixxer +1.9 \| October 27, 2009 at 5:50 PM 0
I would like to use one of these to detect something like paint on a steel cable, to detect the cable position when moving between pulleys (Virtual cable stops without putting 'bumps' on the cable). Is there some sort of liquid paint-like substance that I can purchase, which this thing will detect? TIA.

Manuel

+1.2

| November 1, 2009 at 6:12 AM

Well... if you mix an element that can be easily ionized in the paint. That way you'd be able to detect the ionizing radiation from the paint probably. I don't know for sure as I don't have much chemistry knowledge. I would say, that be one expensive cable detector or whatever you want. Anyway, the Geiger counter can detect many things, whats important is you knowing what you are detecting depending on the energy spectrum of the beta particles. I could attach a small drawing/diagram of how I would build my beta ray spectrometer by using stuff sold at sparkfun.

	by Briansw +2.7 \| November 10, 2009 at 7:55 AM 0
Just a suggestion as I did some research on measuring both speed and displacement on steel cables. Check out this website. http://www.polytec.com/usa/158_289.asp These systems are expensive but do the job very well.

	by BroHogan +3.1 \| January 16, 2010 at 1:47 PM 0
If you build the circuit shown in the schematic and it doesn't work, try reversing the connections to the primary on the transformer. (The common connection between the primary and secondary uses the opposite phase of each winding.)

	by ngmsparkfun +1 \| January 22, 2010 at 3:30 PM 0
I'm wondering if you could describe how your voltage multiplier works, it seems to be quite similar to a Villard cascade of doublers but not quite. I'm suprised you're able to take 5V and get it up in the 450V range with so few stages...

	by ngmsparkfun +1 \| January 22, 2010 at 3:33 PM 0
I've assumed the transformer is 1:1 and used only for isolation but perhaps I'm wrong and this is providing a voltage step up?