Electronic personal dosimeter heralds a revolution in legal dosimetry

The Electronic Personal Dosimeter (EPD) developed by Siemens Plessey Controls and the UK's national Radiological Protection Board is approaching the pre-production stage. It provides ''legal'' dosimetry and all the features of a personal alarming dosimeter. The EPD uses solid state semiconductor detectors for gamma and beta radiation and has a dose threshold of about 1μ Sv, with a low energy gamma range down to 20 KeV. It has a multi function liquid crystal display for instant readout and audible and visual alarms. Two separates dose stores are maintained. Short term dose for tactical management and long term dose for approved dosimetry service record keeping. The latter can be reset only by an approved dosimetry service and is maintained on a search memory disk which can be read even if the EPD is destroyed. (UK)