| 摘要 |
PURPOSE:To eliminate electrical contacts from a liquid level detecting element and enable it to be constituted from glass or the like, which is excellent in corrosion resistance, by leading the beam of light from a light-outputting fiber to a light-inputting fiber through lens systems and a prism arranged on the optical path, and making the reflecting and refracting surface of said prism capable of contact with a liquid to be detected. CONSTITUTION:The optical liquid level detecting element comprises input-side and output-side optical fibers, lens systems to optically combine with the fibers, and a prism provided between said lens systems and whose reflecting and refracting surface is capable of contact with a liquid to be detected. For example, rod lenses 130 and 140 are arranged on the straight line including an input-side optical fiber 110 and an output-side optical fiber 120 which are covered with coatings 111 and 121 respectively. Moreover, a prism 150 is arranged between said rod lenses, and this is encloed in a case 160. In addition, the prims 150 is made capable of contact with, e.g., an aqueous solution. Thereby, when the prism is submerged in the aqueous solution, the reflactive index changes, so that the quantity of light entering the output-side optical fiber 120 decreases. Accordingly, the quantity of water can be detected. |
