Geiger Counter

[Jon86]

I've been looking into building myself a geiger counter as the ones already on the market are very expensive.
I did a lot of research into schematics but I'm having trouble finding something simple enough. I can probably sort out the HV Circuitry myself, but I'm still trying to work out a circuit for registering the pulses.
Any help would be greatly appreciated,
Thanks.

[kripton2035]

on my web site (address below) you have plenty of free schematics.

[Jon86]

Great, thanks Kripton 
I'm having a little trouble understanding the russian schematic though, sorry if I'm being dumb, I just can't quite get my head around it... 

[w2aew]

I'm assuming that you looked at this one?  He has several kit options (with or without the tube, bare pcb only, etc.)

http://mightyohm.com/blog/products/geiger-counter/

[c4757p]

I'm having a little trouble understanding the russian schematic though, sorry if I'm being dumb, I just can't quite get my head around it... 

It's really, really terribly drawn, like somebody just scattered components and drew lines between them. Try redrawing it.

It also uses at least one incorrect symbol (the 2N7000 MOSFET drawn as a JFET) and makes it really hard to figure out what's going on because the component values aren't with the components.

[Jon86]

I'm assuming that you looked at this one?  He has several kit options (with or without the tube, bare pcb only, etc.)

http://mightyohm.com/blog/products/geiger-counter/

No I haven't seen this one before, I looked at the schematic and it makes a lot more sense.
Thank you for the help guys.   

[SeanB]

Most expensive part is the tube, the rest is either cheap or easily gotten.

[Jon86]

Most expensive part is the tube, the rest is either cheap or easily gotten.

Indeed, but even the tubes can be quite cheap on Ebay.
I wonder why pre-built ones cost so much? Is it just that so few people want one?

[ve7xen]

You may find bunnie's design log interesting: http://www.bunniestudios.com/blog/?p=2218

[Jon86]

Wow!
If only I had the skill and tools to make something like that...

[MikeK]

For what it's worth: The June 2011 issue of Elektor had a radiation measuring project that used a cheap diode.

[c4757p]

For what it's worth: The June 2011 issue of Elektor had a radiation measuring project that used a cheap diode.

I can't think of any application for a Geiger counter where it's acceptable and safe to half-ass it with a diode.

[Guppzor]

Another good source:

https://sites.google.com/site/diygeigercounter/home

He provides kits, schematics, firmware, and other useful bits of info such as tube types and sensitivity.

I actually just received a kit from him this morning. Now I just have to find some spare time (and my workbench) to assemble it 

[MikeK]

For what it's worth: The June 2011 issue of Elektor had a radiation measuring project that used a cheap diode.

I can't think of any application for a Geiger counter where it's acceptable and safe to half-ass it with a diode.

School project, science fair, weather balloon payload...

Jon86 didn't say what he wanted it for, but I assumed it wasn't for building a time machine out of a Delorean.

[Jon86]

Thanks, I'll look into the diode one
And actually it's just for myself, I wanted to give it a go for fun and maybe learn something along the way

[Psi]

Electronic goldmine have a selection of geiger tubes for sale
http://www.goldmine-elec-products.com/products.asp?dept=1473

Make sure you know what type of geiger counter you want to build.
They vary in terms of the particles they detect and their sensitivity.

eg, If you want to detect background radiation you want a sensitive tube.

[penfold]

For what it's worth: The June 2011 issue of Elektor had a radiation measuring project that used a cheap diode.

I can't think of any application for a Geiger counter where it's acceptable and safe to half-ass it with a diode.

There are a range of dosimeters on the market that use photodiodes, they seemed pretty nice, and detection characteristics were consistent,

With the diode based system you can perform some gamma spectroscopy, get some information about the energy levels of the gamma and make a reasonable guess at what isotopes are emitting them.  The diode is certainly the cheapest option of doing that and its just not possible with a geiger tube.

It seems generally that demand for geiger based measurement systems has dropped off in recent years in favour of ion chamber and solid state detectors. Ion chambers are nice detectors, well worth considering unless you're after a portable personal dosimeter style detector.

Dan

[belasajgo]

I made a geiger counter using the MightyOhm board as a detector, and to process the data (to count the pulses) and display the value I used the Xilinx Spartan 3E FPGA development board.



I actually decided to buy the MightyOhm geiger counter board and not make the detector circuit from scratch, because I had no possibility to buy all the needed components from the local stores. And the MightyOhm board has a pulse output, so it has all I needed.

I also own a professional geiger counter, but making one myself using my FPGA development board was fun...

[Jon86]

Wow, I'd love an FPGA development board but those suckers cost a bloody fortune! Ah well, maybe one day...

[Stonent]

Wow, I'd love an FPGA development board but those suckers cost a bloody fortune! Ah well, maybe one day...

Well you could start with a CPLD dev board. Dangerous Prototypes has 3 different ones for $15 each.

[belasajgo]

Wow, I'd love an FPGA development board but those suckers cost a bloody fortune! Ah well, maybe one day...

There are various low-cost FPGA development boards from Xilinx and Altera, which do not cost very much. As example the Xilinx Basys 2 or the Altera DE0-Nano. Each board costs less than 100 $, and if you are a student, then you can get them even cheaper.

[vtkkorhanjoh]

If you are still concidering using a diode, try looking into the Teviso rd2014 sensors. Awesome little devices, but kind of hard to get and cost about 80 euros. However, you don't have to mess about with HV stuff, And are Quite sensitive for their small size and technology. They are just slightly bigger than the footprint of my thumb! Would probably be a cost-effective and highly integratable alternative to using a Geiger-Müeller tube. A bit more modern, too!
Good luck!

[Stonent]

As soon as I can get the cap off of my 2N3055 I'm going to test it with alpha radiation.

There's also a way to detect ionizing radiation with a NPN Darlington with a long base pin going through a metal can (without touching)

[nomadtronics]

There's also a way to detect ionizing radiation with a NPN Darlington with a long base pin going through a metal can (without touching)

Hi Stonent  Could you please elaborate on this ? maybe a link to more info ??  it sounds interesting.

[jpittner]

I made one some time ago, with ATmega MCU, see http://www.pittnerovi.com/jiri/hobby/electronics/geiger/
for schematics and open source firmware.