• The Model 3500-1000 Radiation Monitor System is designed to detect low levels of radiation in loads passing through the system. Two scintillation detectors, each containing approximately 480 cubic inches of plastic detector media, provide coverage on both sides of a vehicle. The detectors' large size, 48 inches long by 5 inches wide by 2 inches thick, provides a large area for the capture of gamma radiation. The detectors are housed in weather-tight PVC pipes. The microprocessor based electronics is constructed in a steel box. This unit provides automatic background compensation and automatic alarm point setting above the current background reading. Each detector has its own high voltage power supply to minimize the risk of total system failure. Each detector is also equipped with infrared sensors to detect and approaching vehicle which signals the controller to begin monitoring. The monitor is very easy to use and requires only minimal operator interaction. Upon power up, the monitor requires approximately fifteen seconds to measure background readings. It is then ready for operation. Diagnostic routines provide assurance that the system is operating correctly and indicators warn of possible detector failure. Meter override buttons check the count from each detector. Alarm settings are internal, allowing for tamper-resistant operation of the system. A digital RS-232 output is provided for connection oaf computer or printer. An alarm relay output is also provided to drive additional beacons or sirens in an alarm condition. An infrared sensor is placed with the detectors. The sensor is used to signal the microprocessor to switch from updating background to monitoring for an increase in radiation level.

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