| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical fiber vibration sensor excelling in detection sensitivity over the full longitudinal length and capable of finely identifying the intruding position of any intruder. <P>SOLUTION: Two optical fiber loops 2a and 2b are so arranged in the longitudinal direction as to be at least partly along each other; the two optical fiber loops are so arranged that the sensitivity of vibration sensing by one optical fiber loop 2a decreases from one end toward the other and the sensitivity of vibration sensing by the other optical fiber loop 2b increases from one end to the other. A vibration occurrence determining unit 18b that determines whether or not vibration has occurred in a structural body on the basis of the sum of outputs obtained via the two optical fiber loops 2a and 2b and a vibration position determining unit 18c that determines the vibration occurring position in the structural body on the basis of an output ratio obtained by division of the difference between the sum of outputs obtained via the two optical fiber loops 2a and 2b by the sum of outputs obtained via the two optical fiber loops 2a and 2b are further provided. <P>COPYRIGHT: (C)2013,JPO&INPIT |
