| 摘要 |
PURPOSE:To reduce a volume of a float, provide an effective utilization of a volume of a drain tank and recover condensed water by a method wherein a light receiving element is disposed at a position where a reflected light is guided by a reflection plate when a water level in the drain tank shows a full level of water. CONSTITUTION:A reflection plate 22 of which one end is rotatably supported around a shaft 21 and of which other end has a float 23 is disposed in a drain tank 9, a light from a light emitting element 24 is reflected and incident to light receiving elements 25 to 27, respectively. The light receiving elements 25 to 27 are disposed at least at a position where the light reflected by the reflection plate 22 is incident when the water level in the drain tank 9 is full of water, thereby at least the full state in the tank can be detected. Since this state can be optically detected, a force required in performing a mechanical sensing is not required, resulting in that a size of the float can be reduced. |
