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Types of Personal Radiation Monitoring Devices

A personal radiation monitoring device -- a dosimeter -- is worn in a job environment where an employee is occupationally exposed to ionizing radiation. These devices are typically small, passive instruments -- usually packaged as "badges" -- worn for a specific period of time to record your integrated dose received. A few dosimeters are active and can display your dose rate as well as cumulative dose.

  1. Film Badge Dosimeter

    • A film badge is a one-time, one-use only, personal dosimeter. Film dosimetry was one of the first technologies used to measure personnel exposure. The badge contains a special, radiation-sensitive film. At the end of the device's designated period of issue, you return the badge to the issuing organization. The issuer will process the film and assess and record the accumulated dose. Once processed, the film itself becomes part of the permanent dose record. A new film badge is issued to you as a film badge cannot be reused.

    Thermoluminescent Dosimeter

    • A thermoluminescent dosimeter (TLD) is worn for a designated period and processed at the end of that time. A replacement dosimeter will be issued for another wear period. The TLD is read by specialized equipment. The process of reading the dosimeter (heating to high temperature) 'zeroes' the device. Thus, TLDs can be exposed, read and re-issued multiple times.

    Optically Stimulated Luminescence Dosimeter

    • Areas marked with this symbol have a potential radiation exposure risk.

      The optically stimulated luminescence dosimeter (OSLD, or OSL) is also issued to a worker for a specific period of time. OSL technology is the most recent innovation in personnel monitoring devices. Like TLDs, OSLs can be returned to service after they are read. But unlike TLDs, reading an OSL does not zero the dose. OSLs can only be zeroed out by a special annealing process.

    Direct Reading Pocket Dosimeter

    • The direct reading pocket dosimeter (DRD) is sometimes used along with one of the other types as a supplemental device. As the name suggests, the DRD directly displays the dose reading for you to read, helping you to keep track of the dose you have received as you work. This helps you keep your dose below allowable limits. You can remove yourself from exposure if you are approaching exposure limits. DRDs are generally issued commensurate with higher work-area radiation levels to help radiological workers monitor their doses closely.

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