| 摘要 |
PURPOSE:To detect momentary liquid level positions accurately without receiving the influence of the fluctuations of ambient temp. and the characteristics of transmitters and receivers by detecting the liquid level positions directly with a pair of ultrasonic transmitters and receivers and reading the heights thereof directly from the relative positions of a supporting body. CONSTITUTION:Ultrasonic signals are emitted with a transmitter 7 by an electric power source 16 and are received with microphones 8, 9. The respective microphones transmit the output signals to a signal processing part 19 according to the positions above the liquid level 3 or in the liquid. The part 19 feeds an output signal 1 or 0 to a control circuit 20 according to the input signals. Thereby, a motor 13 is driven clockwise/counterclockwise. As a result, a supporting body 10 is moved upward or downward. The position in the vertical direction of the body 10 is detected with a position transducer 21, whereby the display of its position is made possible. |
