Function

• It's often important for health and safety reasons to be able to detect radiation. A high level of radiation at a nuclear power plant or nuclear waste site, for example, might indicate a health hazard. Geologists use radiation detectors to help locate radioactive minerals like uranium ore. In medicine, imaging techniques like positron emission tomography (PET) use radioactive isotopes and radiation detection equipment to study body functions and diagnose abnormalities.
  
  

Types

• There are three broad types of radiation detectors: ionization counters, scintillation counters and particle track devices. Although any of the three types can be used to detect ionizing radiation, each type functions differently.
  
  

Effects

• When ionizing radiation strikes the atoms of a low-pressure gas in an ionization counter, electric current can for a brief instant flow through the gas between two electrodes. The electrical signal can be recorded to measure the intensity of radiation. Geiger counters are among the most common kinds of ionization counters; while they are good at detecting beta particles, they aren't quite as efficient in monitoring gamma rays. Scintillation counters use substances like zinc sulfide that emit flashes of light when they are struck by ionizing radiation. Particle track devices use bubble chambers in an intense magnetic field to monitor the motion of particles in the field and visualize the path they take.