| 摘要 |
PURPOSE:To eliminate erroneous movement of an float, and make it small in size and give it high reliance by forming a prismatic reflection surface that reflects light from a luminous body to the light receiving body on the outer face of an insulator that is positioned opposite to the luminous body and the light receiving body. CONSTITUTION:A prismatic reflecting surface 4 of conical shape or triangular column shape is formed on the outer face of an insulator 2 that is opposite to a luminiscent body 3a' and a light receiving body 3b' to reflect the light from the luminous body 3a' to the light receiving body 3b' when the fuel 7 is not existing. The tip of a pair of sensitive electrodes 6 embedded in the insulator 2 is positioned beneath the reflecting surface 4 in order to sense water mixed in a fuel tank 1. When the level of the fuel 7 goes down to expose the reflecting surface 4, the light from a luminous element 3a is reflected on the surface 4 and reaches a light receiving element 3b to actuate an indication control circuit, informing emptiness of the fuel tank 1 by lighting an indication element such as LED, etc. |
