Goods/personnel protection surveillance zone alert/alarm having presence detector feeding comparators and differentiating detection zones with control unit selectively zone activating alarm.

摘要

The zone surveillance alert or alarm system has a unit placed in a fixed zone area. The unit has a presence detector (10) for a space zone. A detection signal is delivered which varies with the intrusion position. Comparators (18,19) allow the intruder location to be differentiated between a first and second zone. The alarm is raised (11) following the receipt of a signal in a command activated (15) zone.