Dosimetern

Dosimetern is a family of devices designed to measure exposure to ionizing radiation. They can be worn by individuals or installed in work environments to estimate the dose or dose equivalent received. Dosimetern are central to radiation protection, enabling monitoring of occupational exposure, ensuring regulatory compliance, and informing medical decisions after exposure. The term is used in several languages, with minor regional variations in spelling and scope.

Most dosimetern fall into two broad categories: passive and active. Passive dosimeters record dose for later analysis; common types include film badges, thermoluminescent dosimeters (TLD), and optically stimulated luminescence (OSL) devices. Active dosimeters, or electronic personal dosimeters (EPDs), provide real-time readouts, alarms for high dose rates, and data logging, enabling immediate risk assessment during work.

Operation varies by type. In TLD, ionizing radiation traps energy in crystal lattices; subsequent heating releases photons proportional to absorbed dose. OSL uses light to read stored energy and can be reset. Film badges rely on changes in photographic emulsion, while EPDs use semiconductor detectors to measure current or charge generated by incident radiation.

Dosimetern are used in medical radiology, nuclear power, industrial radiography, research laboratories, and aviation to monitor exposure from X-rays, gamma rays, and neutrons. Calibration and dosimetric protocols align with national and international standards, with measurements traceable to metrology institutes. Quantities include personal dose equivalent Hp(10) for whole-body dose and Hp(0.07) for skin, or ambient dose equivalent H(10). Early dosimetry evolved from photographic film to TLD and OSL, with electronic dosimeters becoming common in the late 20th century.