| 摘要 |
<p>PURPOSE:To prevent a decline in measurement accuracy resulting from a gas convection by winding an optical fiber around a metallic cylinder almost coaxial with a conductor in the state of a coil. CONSTITUTION:The light from a light source enters a tank 1 after passing through a sending optical fiber 4a and airtight optical terminal 3 and is introduced to a coupled optical system in the tank 1 where the light is polarized to linearly polarized light. The light made incident to a sensor 14 advances around a conductor 10 and the plane of polarization of the light rotates upon receiving a Farady effect from the magnetic field formed by the conductor 10. The light with rotating plane of polarization is again made incident to the coupled optical system, led to the outside of the tank 1 through a receiving optical fiber 4b, and transmitted to a detector. Since the sensor 14 is positioned on a shielded cylinder 12 connected to the tank 1 through a ground section 13, the sensor 14 and optical fibers are not required to bear insulation. Therefore, all propagating routes other than the coupled optical system can be constituted of optical fibers and a decline in measurement accuracy can be prevented, because no spatial propagation is required near the conductor 10 and, even when an SE6 gas generates a convection due to the heat from the conductor 10, the sensor 14 is not affected by the convection.</p> |
