| 摘要 |
A radiation detection system and method for scanning an object for ionizing radiation are generally characterized by at least one radiation detector which provides an output related to the level of ionizing radiation impinging thereon, a sensing device which evaluates and provides an output related to a shape characteristic of an object being scanned by the radiation detector, and a processor operatively connected to the radiation detector and sensing device for processing the outputs thereof. The output of the sensing device is used to compensate for variations in ambient background level arising from the sensed shape characteristic of the object. With such a system, the possibility of a geometry induced false alarm is minimized. In a preferred embodiment adapted for dynamic vehicle monitoring, the sensing device is a level detector operative to detect the level of the material in a truck or rail car passing by the radiation detector or detectors. The processor is operatively connected to the radiation detector and level detector for issuing an alarm signal upon satisfying a predetermined criteria, the processor being operative to use the output of the level detector to compensate the output of the radiation detector for variations in the background level arising from differences in the level of the material. The foregoing enables maximum sensitivity to be maintained while eliminating or reducing false alarms arising from variations in scrap loads that otherwise might have triggered a false alarm in previously used systems.
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