| 摘要 |
PURPOSE:To make it possible to grasp the fluctuation of a level accurately regardless of external factors, by projecting measuring light on the surface of the level of water, which is accommodated in a tightly closed containers that are communicated to each other, and measuring the position of the surface of the water based on the receiving position of the reflected light. CONSTITUTION:A optical displacement sensor 40 is fixed together with a water level gage 30 as a unitary body and lowered with the sinking of a material to be measured. Therefore, the distance between the light emitting and receiving part of the sensor 40, which is arranged in a tank 34 so as to face the water surface, and the water surface is decreased in correspondence with the sinking amount. Light is projected to the water surface from the light emitting part. The reflected light is received and undergoes optoelectronic transducing action. The relative displacement of the water surface level is detected as the sinking amount based on the change in light receiving position. Since the sensor 40 is housed in a tightly closed container 58, the effect of atmospheric pressure on the water surface can be effectively cut out. An air pump 62, which is arranged and fixed at a side wall 54 of the container 58, blows dry air, which is supplied through a nozzle from an air feeding pipe, to the light emitting and receiving part, the lens and the like of the sensor 40. Thus steam and the like are removed, and the light is emitted and received correctly. |
