| 摘要 |
PROBLEM TO BE SOLVED: To dispense with a mechanism for retreating or returning a sound wave transmitter-receiver to near the water surface of a supernatant and provide a simple and inexpensive device requiring no separate transmitter-receiver for detecting water level, by providing a sound wave transmitter receiver installed to a supernatant processing equipment to detect the depth of the interface between the supernatant layer and a deposit layer. SOLUTION: In the state where the top end part of a supernatant draining device 10 is landed on the water surface of a supernatant, a mounting pipe 2 is held vertically by the weight of a transmitter-receiver 1 fixed to the top end thereof, and the transmitter-receiver 1 is regularly turned just under. A pulse-like ultrasonic beam is emitted to just under from this position, and a pulse-like ultrasonic beam generated in the interface between the supernatant layer and a deposit layer is propagated to just above, and received by the transmitter-receiver 1. The instruction of the transmission of ultrasonic beam to the transmitter-receiver 1 is transmitted from an arithmetic part set on the outside of a treating tank through a cable 4, and the ultrasonic pulse received by the transmitter-receiver 1 is transmitted to the arithmetic part through the cable 4. |
