A dosimeter is a device used to measure the body's radiation exposure. It is essential to wear it in the right place during fluoroscopy to ensure accurate readings. Generally, the dosimeter should be worn on the chest or abdomen, under the lead apron. A second dosimeter should be worn on the collar outside the lead apron to monitor exposure to the lens of the eye.
For fetal dosimeters, which have a monthly frequency, they should be worn at waist height under any lead garment. Lastly, ring dosimeters should be used on the hand closest to the radiation sources. It is essential that all dosimeters, whether used or not, are returned at the end of each period of use. The TLD badge and ring dosimeter should be returned to the RSO, who will then send them to the radiation safety lab for processing. At the end of the usage period, replacement dosimeters will be distributed through the designated badge coordinator. The purpose of a dosimetry badge is to document occupational radiation exposure and demonstrate compliance with annual dose limits and ALARA levels. Dosimeters are required if a person is likely to receive more than 10 percent of the maximum allowable dose. Returning all radiation dosimeters (full-body badges or TLD rings) is essential.