Device to monitor ionizing radiationAny radiation which directly or indirectly ionizes, e.g. alp... or the activity concentrationQuotient of the activity 'A' of a material and the volume 'V... of radioactive substancesRadioactive substances within the meaning of the Atomic Ener... (e.g. in the air or water) signalling a warning when certain adjustable limit values are exceeded. A monitor is also used for quantitative measurements.