Geiger counter


an instrument for detecting ionizing radiations, consisting of a gas-filled tube in which electric-current pulses are produced when the gas is ionized by radiation, and of a device to register these pulses: used chiefly to measure radioactivity.

Origin of Geiger counter

First recorded in 1920–25; named after H. Geiger
Also called Geiger-Müller counter. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for geiger counter

Geiger counter

Geiger-Mller counter

/ (ˈɡaɪɡəˈmʊlə) /


an instrument for detecting and measuring the intensity of ionizing radiation. It consists of a gas-filled tube containing a fine wire anode along the axis of a cylindrical cathode with a potential difference of several hundred volts. Any particle or photon which ionizes any number of gas molecules in the tube causes a discharge which is registered by electronic equipment. The magnitude of the discharge does not depend upon the nature or the energy of the ionizing particleCompare proportional counter

Word Origin for Geiger counter

C20: named after Hans Geiger and W. Müller, 20th-century German physicist
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for geiger counter

Geiger counter

1924, for German physicist Hans Geiger (1882-1945), who invented it with W. Müller. The surname is literally "fiddler."

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for geiger counter

Geiger counter

[ gīgər ]


An instrument that measures the intensity of radiation by detecting radioactive particles as they cross a metal or glass tube filled with gas, causing ionization of the gas molecules and producing an electrical discharge.Geiger-Müller counter
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for geiger counter

Geiger counter

An electronic instrument that detects and measures nuclear radiation, such as x-rays or gamma rays. The Geiger counter consists of a gas-filled tube with a charged electrode connected to a counter. As radiation passes through the gas it ionizes atoms along its path. The ions are attracted to the charged electrode, creating pulses of electric current that are registered by the counter.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.