Accession Number : ADD010863

Title :   Apparatus for Determining Break Locations in Fencing.

Descriptive Note : Patent Application,


Personal Author(s) : McCormack,R G

Report Date : 19 May 1981

Pagination or Media Count : 9

Abstract : An improved intrusion detection apparatus for detecting when a fence is cut or has been climbed over, as well as the location of the intrusion. A cable comprising at least one optical fiber having an electrical transmission line running there along is strung along the fence to be protected. If an intruder either cuts the cable or stresses the fence so that the cable breaks, an optical signal running along the optical fiber or fibers is lost, thus providing an alarm indication at a central station. The loss of the optical signal automatically triggers an electrical pulse generator means which feeds pulses down the transmission line running along the optical fiber. Part of the pulse energy is reflected at the transmission line break, and the time elapsed between transmission and receipt of the pulses is determined by time domain reflectometry techniques (TDR). (Author)

Descriptors :   *Patent applications, *Warning systems, *Locators, *Intrusion detection, *Detectors, *Position finding, Fiber optics transmission lines, Electric power transmission, Optical properties, Pulse generators, Transmission lines, Time domain, Reflectometers, Intrusion, Signals, Feeding, Stresses, Stations, Energy, Pulses

Subject Categories : Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE