| 摘要 |
PURPOSE:To detect the distance between the inner wall of a bushing and an insulating pipe readily and highly accurately, by measuring the distance between the inner wall of the bushing and the insulating pipe by utilizing the reflection and the transmission of light. CONSTITUTION:A pair of infrared rays, which are projected from a light projector 10, is absorbed by an insulating pipe 12. A part of the infrared rays is transmitted through the pipe 12. The transmitted infrared rays are propagated between the inner wall of a bushing 2 and the insulating pipe 12 and reach the inner wall of the bushing 12. The infrared rays that have reached the inner wall are not transmitted through the bushing 2 but all reflected. The reflected infrared rays are received by a light receiver 11. The amount of the received light is outputted. Based on the output of the amount of the received light, the distance between the inner wall of the bushing 2 and the insulating pipe 12 can be readily detected highly accurately. |
