A radiation dosimeter is a device that measures dose uptake of external ionizing radiation. It is worn by the person being monitored when used as a personal dosimeter, and is a record of the radiation dose received. Modern electronic personal dosimeters can give a continuous readout of cumulative dose and current dose rate, and can warn the wearer with an audible alarm when a specified dose rate or a cumulative dose is exceeded. Other dosimeters, such as thermoluminescent or film types, require processing after use to reveal the cumulative dose received, and cannot give a current indication of dose while being worn.
Radiation dosimeter in Pripyat
View of readout on an electronic personal dosimeter. The clip is used to attach it to the wearer's clothing.
View of quartz fiber dosimeter reading
Chromoradiometer or colour dosimeter by Guido Holzknecht (1902)
Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or inhaled radioactive substances, or externally due to irradiation by sources of radiation.
Joanna Izewska gives Ambassador Frank Recker and his delegation a tour of the IAEA Dosimetry Laboratory.