<Tr> <Th> Inventor </Th> <Td> Hans Geiger Walther Müller </Td> </Tr> <Tr> <Th> Related items </Th> <Td> Geiger--Müller tube </Td> </Tr> <P> The Geiger counter is an instrument used for measuring ionizing radiation used widely in applications such as radiation dosimetry, radiological protection, experimental physics and the nuclear industry . </P> <P> It detects ionizing radiation such as alpha particles, beta particles and gamma rays using the ionization effect produced in a Geiger--Müller tube; which gives its name to the instrument . In wide and prominent use as a hand - held radiation survey instrument, it is perhaps one of the world's best - known radiation detection instruments . </P>

Radiation is detected by an instrument called a