Monitoring devices and intrusion surveillance devices

摘要

A security surveillance device that includes an electromagnetic wave sensor for sensing an electromagnetic wave of an external electromagnetic wave source and an anti-tampering arrangement. The anti-tampering arrangement includes a detection window forming a partition between the external electromagnetic wave source and the electromagnetic wave sensor, the detection window includes an outer corrugated surface facing the electromagnetic wave source; an optical arrangement for deploying an optical surveillance beam which is arranged to undergo multiple reflections at the outer corrugated surface of the detection window is provided and the surveillance beam loop is monitored by a control circuitry to monitor tampering.