| 摘要 |
PURPOSE:To facilitate maintenance and to improve safety by using optical fiber and a sensor of specific structure. CONSTITUTION:Sensor 9 having porous glass 4, made of a glass rod with many pores, inserted between lens 1 and 1 made of a couple of glass rods with prescribed refractive-index distribution is arranged at a submergence monitor point and light source 5 and detector 6 are connected to it via optical fiber 2. Consequently, light transmitted from light source 5 to sensor 9 via optical fiber 2 is scattered and not incident to detector 6 when sensor 9 is not under water, but when sensor 9 is under the water and porous glass 4 is immersed with water, porous glass 4 turns into an even, clear medium to cause the incident light to strike detector 6 without scattering the light. Therefore, submergence detection is carried out in safety without electromagnetic inductive noises and leakage of electricity and the maintenance is facilitated because of no movable part at sensor 9. |
