| 摘要 |
PURPOSE:To quickly detect the position of a precipitation surface, by providing a transmitter and a receiver above a cylinder containing a detected liquid and by measuring the time difference from the emission of an ultrasonic signal from the transmitter to the reception of the reflected signal by the receiver. CONSTITUTION:A transmitter and a receiver 11 are provided at the upper part of the cylindrical body of a precipitation pipe 7 which contains a detected liquid. An ultrasonic signal is emitted from the transmitter, reflected and received by the receiver. The position of a precipitation surface measured in terms of the time from the emission of the ultrasonic signal to its reception. A time elmination circuit is provided between the receiver and a calculation circuit to eliminate signals for a prescribed time since the beginning of entry of the signals. As a result, the measurement is prevented from being affected by flocks floating on the supernatant part of the detected liquid and only the signal reflected on the precipitation surface can be entered as an input. |
