The Geiger-Muller tube - radiation detector (video)

Source: Ionactive Radiation Protection Resource

The Geiger-Muller (GM Tube) is essentially a cylindrical diode filled with a low pressure gas. The central electrode is held at a moderately high voltage. The gas filling is at lower than atmospheric pressure and is adjusted in manufacture so that its initial ionisation by an incident particle or photon, causes subsequent electron - ion pairs to be produced as a result of an accelerating field between the central wire and the cylinder wall.

Find out more by watching the following video.

Further comment

GM tube based monitors are:

  • Robust (but don’t drop one) 
  • Easy to use
  • Relatively cheap
  • Easy to carry (being small and light)
  • Not ideal for measuring pulsed radiation
  • Liable to suffer from RF interference
  • Not applicable for all types of radiation    

Further resource

You may want to consider some practical matters when using this type of equipment. Try this Ionactive resource: Use Counts per Second (CPS) to find it, and Dose Rate to define it

What's the matter? What's the antimatter? Does it antimatter?

– Wes Nisker -