| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure the water level of a liquid such as drain, etc., present in horizontally provided piping. SOLUTION: An ultrasonic transmitter/receiver 2 is mounted to the outside surface of a bottom part of the horizontally provided piping 1. Ultrasonic pulses are periodically transmitted upward from the ultrasonic transmitter/receiver 2, and the waves of the ultrasonic pulses reflected at the water surface 61 of the drain 6 are received. The water level H of the drain 6 is computed from their time difference. The computation of the water level H is executed by a CPU 5. At this time, the CPU 5 computes the water level H of the drain 6 while eliminating the effects of irregular reflection of the ultrasonic pulses due to the dynamic state of the water surface 61 of the drain 6 such as rocking. In the case that the water level H can not be detected, it is determined whether the piping 1 is filled to capacity with water or not from a reflection image in the vicinity of the inside surface of an upper part of the piping 1. |
