The PDM-122 & PDM-127 are electronic pocket dosimeters that use a semiconductor detector that is sensitive to gamma and x-rays. Both models are battery-operated and do not require a charger or separate reader. The PDM-127 and PDM-122 have an automatic zero reset when the unit is turned off.
They range 20 keV and above with a measuring from 1 to 9999 µSv.