The U.S. Navy uses thermoluminescent dosimeters (TLDs) to monitor personnel for radiation exposure.
Since 2010, the entire Navy has adopted the model DT702 dosimeter, shown in the photograph, which has been demonstrated to have improved accuracy and energy discrimination and a lower detection limit than previous models. The newer technology combines the use of filters and four thermoluminescent elements enclosed in a rectangular shaped holder developed by Harshaw. The quantity of interest used for monitoring occupational exposure is the personal dose equivalent. NIST provides support to the Navy quality assurance program by irradiation and characterization of TLDs in the NIST reference standard 137Cs gamma-ray beams.