The most common methods of radiation detection in use today are gas ionization and scintillation. The gas inside the detector chamber is ionized by the incident radiation. Gas ionization detectors are typically more rugged and less expensive than scintillation detectors. Gas ionization detectors are not as sensitive for detecting low-level radiation as are scintillation detectors. The photomultiplier tube then detects, converts and amplifies the light signal to an electrical signal.
Scintillation detectors provide the best sensitivity for the detection of low-level radiation.
Scintillation detectors are fragile, sensitive to exposure to light, and generally are the most expensive type of detectors. Due to their enhanced sensitivity, scintillation detectors are only considered useful in areas with low levels of background radiation.