GM Counter Measuring Radiation

The GM counter is an instrument used for measuring ionizing radiation. It is used widely in applications such as radiation dosimetry, radiological protection, experimental physics and the nuclear industry. It detects ionizing radiation using the ionization effect produced in a Geiger-Müller (GM) tube. Geiger counter instruments consist of two main elements: the Geiger-Muller tube and the processing and display electronics. The radiation sensing element is an inert gas-filled Geiger-Muller tube (helium, neon or argon) which briefly conducts electrical charge when a particle of radiation makes the gas conductive by ionization. There are two main limitations of the GM tube. Because the output pulse from a GM tube is always the same magnitude regardless of the energy of the incident radiation, the tube cannot differentiate between radiation types. Another limitation is the inability to measure high radiation rates due to the dead time of the tube. This is an insensitive period after each ionization of the gas during which any further incident radiation will not result in a count.