| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform highly accurate measurement even in the environment, wherein temperature change is large, and to improve the strength and the life of an optical fiber by suppressing the occurrence of the double refraction caused by the temperature change in the optical fiber. SOLUTION: A flange-shaped sensor part 10 is arranged between tank flanges 4a and 4b of an insulated closed tank 2 of a gas-insulating opening and closing device containing a conductor 1 and an insulating medium. From the sensor part 10, light sending and light receiving fibers 11 and 12 are drawn out and connected to a light source 14 and a detector 15 of a light-source/detector part 13, which are arranged at the separate polisions, respectively. The light-source/ detector part 13 has a signal processing circuit 16, which computes the conducting current from the output signal from the detector 15, and an output terminal 17, which outputs the result of the operation. In the sensor part 10, the optical fiber comprising quartz fiber is used. A coating layer comprising silicone rubber having the thickness of 1mm or less is provided at the outer side of the optical fiber.</p> |
