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Types of Dosimeter in Radiation Monotiring

There are two primary types of dosimeters worn by persons who work with or
near sources of radiation.
 The Film badge is film wrapped in light‐tight paper and
is mounted in plastic. Badges are checked periodically, and the degree of
exposure of the film indicates the cumulative amount of radiation to which the
wearer has been exposed. 


Thermoluminescent dosimeters (TLDs) are crystalline
solids that trap electrons when exposed to ionizing radiation and can be
calibrated to give a reading of radiation level. Film badges are most often worn by
hospital staff potentially exposed to x‐rays or researchers working with higher
energy beta emitters. TLDs are most often worn by persons exposed to a variety
of isotopes such as found in nuclear medicine or the cyclotron facility. All
dosimeters are processed by a contractor. They are collected the first week of
every wear period. Most monitors can read as low as 10 millirem.

The regulations require monitoring for any worker who might exceed 10 percent of
the applicable limit, and any worker entering a high or very high radiation area.
Monitors are usually recommended for projects authorized to 5 millicuries of
photon‐ or high energy beta‐emitters, and XRD operators. Dosimetry will be issued
when evaluation establishes a need for the use of this monitoring technique.
Requirements will be stated in the Hazards Evaluation. See Table 2.1 for the dose
limits.

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