Dose rate dependency of electronic personal dosemeters measuring x- and γ-ray radiation

Three models of EPDs Siemens Mk 2.3, Rados RAD-60S, and Vertec Bleeper Sv were irradiated with seven photon beam qualities: Co, Cs, and the ISO narrow spectrum series x-ray qualities N-250, N-200, N-150, N-60 and N-20. The personal dose equivalent rates delivered to the devices varied in the range between 0.002 and 0.25 mSv/s. Measurements were made with the EPDs mounted free-in-air as well as against Lucite and water phantoms. The results for all models of EPDs showed differences in personal dose equivalent energy response for the different energies covered by this range of radiation qualities, with different models showing variations from 15% to 65%. In some cases, the personal dose equivalent rate response of these devices varied by a factor of 3 between irradiations at typical calibration dose rates and the dose rates normally encountered by nuclear energy workers.