Radioactivity detection portals

Operating principle of vehicle radiation monitor is based onι detection units, which detect gamma and neutron radiation. One or two detection units are located and wired inside a cabinet to form a measurement device. Measurement devices are mounted on posts arranged on both sides of vehicle passage lane Two or one measurement device are mounted on each side of the passage depending on external dimensions of vehicles to control

After initialization the alarm dosimeter switches to natural radiation background measurement mode. This procedure is indicated by a yellow light on Alarm unit. When this measurement procedure is over the count rate threshold levels is calculated and a green indicator lights when the alarm dosimeter is ready for operation.

When a moving vehicle crosses the control zone line, it breaks the beam from the IR emitter to the photoelectric detector IR receiver, and all detection units are automatically switched from the background measurement mode to the detection mode. Count rate data from each detection unit in detection mode is transferred through RS 485 interface to a remote control panel, which is located in a control room.

When the set count rate threshold level is exceeded the audio and red light alarm is actuated on the Alarm unit to inform the staff about gamma or neutron radiation source detection.

In case of malfunction of one or multiple detection units the radiation monitor recalculates threshold levels for the rest detection units.