| 摘要 |
PURPOSE:To make it possible to control combustion so as to prevent a bath boiler from heating the bath without water, by detecting that the water level in a bathtub in a min. level or less by a simple constitution equipped with an electrode part and an oscillator. CONSTITUTION:Two opposed electrode parts 9a, 9b are provided and a water level is calculated by utilizing that the electrostatic capacity value between said electrode parts changes corresponding to the constitutional ratio of air and water in a communication pipe 5. That is, when the frequency of the output pulse from an oscillator 7 having the electrostatic capacity between the electrode parts 9a, 9b as a time constant element is set to (f) and the water level of the communication pipe measured from the lowermost ends of the electrodes parts 9a, 9b to (h) and measured frequency to (f1), the water level of the communication pipe is h1 at this time. Therefore, if a bathtub is planned by setting the height from the bottom of the bathtub to the lowermost ends of the electrodes parts 9a, 9b to h0, the water level H of a water tank 2 is h0+h1. Therefore, by constituting the bathtub so as to bring the position 8 of the lowermost ends of the electrode parts 9a, 9b to the height of an upper side water passing pipe 4a, necessary water level information is obtained by the short communication pipe 5 and the electrode parts 9a, 9b. |
