| 摘要 |
PURPOSE:To make it possible to always certainly monitor the state of an optical fiber, by detecting the tension of a thermoplastic wire provided along an optical fiber. CONSTITUTION:The title apparatus is equipped with a holding member 20 for holding the emitting side of the thermoplastic wire 21 provided along an optical fiber 14 and fixing one end thereof and a tension detector 23 present in the insident side of the optical fiber 14 and mounting the other end of the thermoplastic wire 21 in a hanging state and detecting the tension of said wire 21. When damage was generated in the optical fiber 14 by any cause and said optical fiber 14 was fused, the thermoplastic wire 21 is instantaneously heated to temp. equal to or more than thermoplastic temp. by laser beam from the fused part of the thermoplastic wire 21 through a metal tube 19 and fused. By this phenomenon, the balance between the repulsive force of a spring 25 and the tension of the thermoplastic wire 21 is lost and a tube holder 22 is slid to an A-direction and the resistance value of a slide volume 26 changes and, by detecting this change, the fusion of the optical fiber can be detected. |
