INVASION MONITOR SENSOR UTILIZING OPTICAL FIBER CABLE

摘要

PROBLEM TO BE SOLVED: To provide a sensor system, which is practical for a facility having the security monitor line of a long distance, reduces an erroneous operation, facilitates the maintenance as well and further can be used even in an airport or the like without affecting radio communications or the like. ;SOLUTION: This invasion supervisory sensor utilizing on optical fiber cable is provided with a pulse oscillator 1, a light emitting element 2 to be driven by the pulse oscillator 1 for generating a light pulse, optical fiber 4 laid within the range to be monitored for receiving light emitted by the light emitting element 2, light receiving element 6 for receiving Fresnel reflected light (Brillouin scattered light) in the optical fiber 4, and optical fiber cutting position determining part 10 for detecting the occurrence of an abnormality and specifying a spot, where abnormality occurs, by monitoring time from he generation of the light pulse to receiving of the Fresnel reflected light.;COPYRIGHT: (C)2001,JPO