| 摘要 |
PURPOSE:To prevent chattering and wavering caused by shaking of a liquid level, by fit-inserting a float having an operating magnetic pole into the inside of a stand column, and providing a sensor unit consisting of upper and lower magnetic switches for operating a set coil and a reset coil of a relay, on two places whose heights are different from each other. CONSTITUTION:A float 3 is fit-inserted into the inside of a stand column 2 which communicates to a tank 1 and is fitted vertically, and an operating magnetic pole 40 is provided on its liquid level position. A sensor unit 60 is provided on a low water level cut-off position in the outside of the stand column 2. Both magnetic switches 61, 62 are constituted so that both of them become on-state when the operating magnetic plate 40 is positioned at each height b', a', and become an off-state in other case. An alarm sounding device and an alarm lamp 7 continue the alarm operation until a reset coil 82 is operated and a relay 80 is switched to an off-state. |
