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Geiger counterJoe Segen2016-12-03T21:52:40+00:00
Definition An instrument used to detect ionising radiation, the “business” end of which has a Geiger tube filled with an inert gas under low pressure–e.g., helium, neon, or argon with halogens added, ionised by passing particles. Geiger counters are highly sensitive to alpha and beta particles, but less so to gamma radiation, given that the Geiger tube measures the number of ionising events, but not their intensity, and thus doesn’t differentiate among alpha, beta and gamma radiation.
Comment Despite their limitations, handheld Geiger counters are the most commonly used and recognised detector of ionising radiation.