The AT2503 and AT2503A Personal Dosimeters are lightweight pocket-sized microprocessor controlled units that offer exceptional accuracy and reliability. They can be used standalone or as part of an automated monitoring system, when combined with a reader with PC connection. These units feature simultaneous personal equivalent x-ray and gamma radiation dose and dose rate monitoring (in the energy range from 50 keV to 1.5 Me), continuous self-testing of detector and cells discharge, audible and visual alarm system and pulsed x-ray radiation alarming mode (pulse duration > 10 ns). They feature a construction that is highly resistant to impact and vibration, as well as dust, water and electromegnetic interference. They are often used in nuclear industry, nuclear medicine, radiology, NDT, emergencies, civil aviation, research and population dose burden monitoring.