Vibration sensor

Abstract

This patent pertains to a system for detection of intrusions or tampering. It uses a series of sensors, each consisting of a glass ampoule that has conductors extending into it at its top anal bottom and is partially filled with mercury. The sensors are connected to an impedance reflectomerry system via impedance-matched coaxial cables, enabling one to localize the occurrence of a disturbance.--EEU 4,466,738 43.40.Yq VIBRATION SENSOR Cheng-Chung Huang and Tao Chang, assignors to Lockheed Missiles & Space Company 21 August 1984 (Class 356/4.5); filed 23 August 1982The light from a single coherent light source is split into two parts by a Bragg cell. One part is split into several beams by a second Bragg cell, fed to reflectors mounted on the surface to be monitored, recombined, and then heterodyned with the second part. The heterodyned signal is fed to a photodetector and processed to produce a signal representative of the distances between the points of interest on the surface.--EEU