Homemade Geiger Counter Dosimeter

This is a Homemade Geiger Counter and Dosimeter project, using a SBM-20-1 GM tube, controlled by an ATtiny2313 microcontroller (PWM output).
The tube was bought from the GsTube.
The transformer for the HV supply was obtained from a PCI Fax/Modem (Model: VPI56SPA).

How to obtain the uSv/h value for your GC project using other tubes:
First you need your tube datasheet.
Find the cps/mR/h value calibrated for ex. Cs137 source.
For my tube (SBM20) this value is 25 cps/mR/h for Cs137.

Here is the formulas:
1000 / 25 = 40 this is the period of time (in seconds) where one count equals 1uR/h.
CPM * 40 / 6000 = uSv/h.
CPM * 40 / 60 = uR/h

Schematics and firmware:
http://cyberelectronics.org/ (still under construction)
or
http://cyberpcb.com/ (my old webpage)

Use for educational purposes only!

Category:

Science & Technology

Tags:

• geiger
• muller
• counter
• tube
• radiation
• radioactive
• thorium
• radium
• homemade
• electronics
• microcontroller
• gamma
• dose
• rate
• Sievert
• Roentgen
• counts
• CPM

[wugy93]

I have problem with programing microcontroller on avrprog2, can you send me source code of program that i try comple it for my programmer. Thank you.

[cyberelectronics]

@wugy93 The hex code can be used with any programmer.

[statesidestorm]

Are the SBM-20-1 GM tubes any better than the SBM-21 tubes?

[cyberelectronics]

@statesidestorm The SBM20-1 tube is more sensitive than the smaller SBM21.

[goldeneye7100]

It's a beautiful projects. Where can we have the schematic and the source file?

[cyberelectronics]

@goldeneye7100 Thanks. Please read the updated description.

[WildBuck007]

Nice project. But you may not wish to keep to many examples.

I mean...if assuming you don't want a permanent orange afro. =D

[Nonanepod]

Thank you very much,cyberelectronics

I will try to build it to study your video and description.

It is necessary for me to live nearby(more than 100km away from Fukushima) Fukushima nuclear power plant.

We have many hot spots far way from Fukushima.

[joozwajoozwa]

@cyberelectronics : hello. Very nice project:) I'm about to build my first GM counter, and I have a question: What is going on on the PB3 (OC1) of the MCU? Does it give constant pulse width (i guess yes, because there's no feedback)? What is the frequency ? I have no access to the particular transformer you mentioned so I'm planning to design different high voltage PSU with choke and charge pump, but still using wave generated on PB3. W'd be grateful for help. joozwa

[iamgoddard]

Wish you showed how to make it, not just that you made one.

[LordPlextor]

Well done :)

My geiger counter is quite similar to yours. I used a ATMega32 on my evaluation board. Smaller version is in development.

Check my channel for further information.

Best regards ;)