| 摘要 |
PURPOSE:To discriminate clearly the accident of optical fiber system and the oil leakage accident by providing liquid sensing layer on the external circumference of optical fiber strand. CONSTITUTION:On the external circumference of optical fiber strand 1 comprising a core and clad, a primary coat 2 comprising resin such as urethane, etc., through a buffering layer 3 such as silicone rubber, etc. and a liquid sensing layer 4 composed of material for generating cracks, or swelling by liquid such as oil, etc. to be detected are disposed. Thus, when the liquid is swelled or immersed in the liquid sensing tank 4, a coating pressure to the optical fiber strand 1 (the cause of microbend) is lowered and the light conveying characteristic of the optical fiber strand 1 is enhanced. Accordingly, when the light receiving level is detected by a light receiving end side of the optical fiber, the liquid leakage accident is discriminated clearly by leveling up and the optical fiber accident be discriminated by leveling down. |
