Personal dosimetry is a key part of radiation dosimetry and is used to measure the doses received by people who are exposed to radiation related to their work activities. These doses are generally measured with devices known as dosimeters, which usually record a dose in gray (Gy) or the equivalent dose in sieverts (Sv). A personal dosimeter is a device that is worn on the surface of the body and records the dose of radiation received.
Personal dosimetry techniques vary depending on whether the radiation source is external or internal. For external radiation, personal dosimeters are used to measure exposures. Internal exposures are generally controlled by measuring the presence of nuclear substances in the body or by measuring nuclear substances excreted by the body. Modern electronic personal dosimeters can provide a continuous reading of the cumulative dose and the current dose rate, and can warn the user with an audible alarm when a specified dose rate or cumulative dose is exceeded.
Badges don't protect you from radiation, but they do document your occupational radiation exposure and demonstrate compliance with annual dose limits and ALARA levels. They also provide valuable information to the Radiation Safety Office regarding the safety of your work environment and the quality of the radiation safety program established for your area.
The purpose of a personal dosimeter is to estimate the radiation dose deposited on a person wearing it. An electronic personal dosimeter is a modern device that can provide a continuous reading of the cumulative dose and the current dose rate, and can warn the user when a specified dose rate or cumulative dose is exceeded. Passive dosimeters and electronic personal dosimeters are often used together to complement each other.
The operating quantity for personal dosimetry is the personal dose equivalent, which is defined as the dose equivalent in soft tissues at an appropriate depth, below a specific point on the human body. This is an actual reading obtained from a gamma ambient dose monitor or personal dosimeter, which can be reset after taking a reading for recording purposes and can therefore be reused several times.