| 摘要 |
PURPOSE:To detect the change in water level in a broad range continuously, by moving a magnetic body in and out of a coil in response to the change in water level in a water tank, changing the inductance of the coil, and thereby detecting the change in water level. CONSTITUTION:Water is put in a water tank 1. Until the time the water reaches a certain water level, the sum of the weights (sum of the dead weights) of a magnet 20, a magnetic fluid 21, a spring 23 and a pressure piece 24 is larger than the pressure of air 7. The magnet 20 is contacted with a stopper 19b. When the water exceeds a certain level, the pressure of the air 7 overcomes the sum of the dead weights, the magnet 20 moves upward, the magnetic fluid 21 is moved and the inductance of a coil 22 is changed because the magnet 20 enters in the inside of the coil. When the magnet 20 moves upward, the inductance of the coil 22 is increased. An arbitrary water level H0 is set by an adjusting screw 25. The water-level change exceeding the set water level can be continuously detected as the change in inductance of the coil 22. |
