| 摘要 |
PROBLEM TO BE SOLVED: To suppress the effect of a large number of side lobes being generated when an interface is detected utilizing an ultrasonic oscillator of high mechanical oscillation. SOLUTION: Ultrasonic oscillators (ultrasonic transceivers) 81-85 of high mechanical oscillation are employed and ultrasonic waves are transmitted from the oscillators 81-85 through a timing circuit 11 and a drive circuit 12 to focus at two positions A and B, for example, at the same depth of water in a tank 1. Receiving signal of the reflected wave corresponding to the focal points A and B is received through a clamp circuit 13 and an amplifier circuit 14 and processed appropriately at a signal processing section 15 to suppress the effect of side lobes and to eliminate the effect of floating matters thus detecting the interface accurately. |
