This Area Monitor serves as a radiation sentry/alert for building entrances, halls, and doorways. Equipped with a pair of NaI (Tl) scintillation detectors that mount on both sides of a doorway or hall, the unit continuously monitors incoming and outgoing materials and people for low-level gamma radiation. Typical applications are the monitoring of areas where waste material leaves departments or buildings, and monitoring emergency room entrances in the event of radiation-related emergencies. The Area Monitor can be set to give a visual and/or audible alert (yellow light, slow beep) when a selected background level has been exceeded, and give an alarm signal (red light, fast beep) when a selected radiation level is reached. Lights and audibles also indicate detector overload, no count from detectors, or instrument failure. A yellow LED illuminates when the battery has less than 2 hours of power remaining. The monitor is wall-mountable. Two 25-foot detector connection cables are included.