Shkalacar Assembled DIY Geiger Counter Kit, DIY Nuclear Radiation Detector Kit with Miller Tube, Portable Geiger Counter, Assembled Radiation Detector System Experimental Module

Love it.You will get around 25 - 30 pulses per minute background. Right near the inside of a smoke detectors opened unit, it will pulse a bit too fast to count without using a circuit/Arduino for that. You can hear there is elevated radiation and it is quite a sensitive tube. You can shut the unit up by removing a jumper, perhaps replace it with a switch? I would be happy with just this but you can go a step further and hook the output to a computer, Raspberry Pi, or Arduino.There is one issue though, but it's not the fault of this unit, you can get these very accurate and use it on an Arduino to measure uS/H (microsieverts per hour) , you can compensate to mearsure radiation in a linear fashion. The thing is you will sledom get the actual conversion rate for this particular tube since the sellers don't know what it is themselves. There is also other confusion involved. I will post a pic of some of the popular geiger/Muller tube info data. It comes with a J305 tube. If you replace it with a Russian tube make sure to calculate the rate according to their data sheet. This is the correct conversion for the j305 : 0.0038 = strait conversion301.03 = 0.0033 compensated for absorbtion.I will also include a circuit diagram. Unit calibration is available online but only needed when you purchase units you have to build yourself.

Good product.

Documentation is lacking

No instructions need a case