A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, plastic (usually containing anthracene), or organic liquid (see liquid scintillation counting) that fluoresces when struck by ionizing radiation. A sensitive photomultiplier tube measures the light from the crystal. The photomultiplier (PMT) is attached to an electronic amplifier and other electronic equipment to count and possibly quantify the amplitude of the signals produced by the photomultiplier.

The scintillation counter is based on the work of Antoine Henri Becquerel, who discovered the phosphorescence of certain Uranium salts.

Scintillation counters are the most sensitive-known radiation detectors.

See also

• Dosimeter
• Radiation
• Geiger counter