| 摘要 |
PURPOSE:To make it possible to detect a position accurately and stably, by arranging a light emitting part and a light receiving part, which faces the light emitting part, at positions for detecting liquid and the like in a tank. CONSTITUTION:When a liquid 4 in a liquid level detecting part 9 comes to a position, where light from a light emitting part 7 is shielded, the output of a light receiving part 8 disappears. Therefore, the level position of the liquid 4 in the tank can be detected by detecting the output of the phototransistor of the light receiving part 8. Namely, the H-level position of the liquid 4 in the tank 5 is detected by a pair of the light emitting part 7 and the light receiving part 8, which are provided at the upper part of the detecting part 9, and a liquid-level detecting relay 2a. The L-level position of the liquid 4 in the tank 5 is detected by a pair of the light emitting part 7 and the light receiving part 8, which are provided at the lower part of the detecting part 9, and a liquid level detecting relay 2b. |
