| 摘要 |
PURPOSE:To restrain the occurrence of a fault and increase the accuracy of a level measurement by providing a transparent member in an oblique direction with respect to the direction of the optical axis of a light wave emitted from a light receiving portion through a lens so as to shield the direction of the optical axis. CONSTITUTION:A light wave emitted from a light receiving and transmitting portion 13 and converted to a parallel light by a lens 15 passes through a transparent member 19 and, at the same time, a part of the light wave is reflected by the transparent member 19. At this time, since the transparent member 19 is provided in an oblique direction with respect to the optical axis of the light wave 30 emitted from the light receiving and transmitting portion 13, a reflected light 31 from the transparent member 19 is directed in a direction deviated from the light receiving and transmitting portion 13. Therefore, this reflected light 31 does not affect another reflected light that is returned to the light receiving and transmitting portion 13 after transmitted through the transparent member 19 and reflected by a liquid surface. Further, since the light receiving and transmitting portion 13 and the like are hermetically sealed by a level meter body 14 and the transparent member 19, a fault can be restrained and a measuring accuracy can be increased. |
