| 摘要 |
PURPOSE:To enable a precise measurement by arranging one end of a plurality of transmission fibers vertical to the bottom surface of a prism while a plurality of receiving fibers are arranged in pairs with the transmission fibers on the side where incident light from the other end thereof reflects in refraction on the prism. CONSTITUTION:One end of a plurality of transmission fibers 4 is arranged at the right angle to the direction parallel to the edge line 38 on the bottom surface 32 of a prism 3 while the other end thereof is bundled so that light 7 enters a light emitting element 6. This light 7 is fully reflected at the projection point on the surface 3a of a prism 3 through the transmission fibers 4 and again, fully reflected at the projection point on the surface 3b opposite thereto. Receiving fibers 5 are arranged at the point where the light thus reflected arrives in such a manner as to be in pairs with the transmission fibers 4. Therefore, for example, when the projection points corresponding to the transmission fibers 44- 4n and the receiving fibers 54-5n thus paired are immersed in a liquid, the end of the receiving fibers 51-53 lights but the end of those 54-5n does not, thereby enabling the detection of the liquid level in a liquid vessel 1 depending on the light at the end of the receiving fibers 5. |
