ULTRASONIC FLOWMETER AND METHOD FOR JUDGING ABNORMALITY IN ULTRASONIC ABSORBER

摘要

An objective of the present invention is to provide an ultrasonic flowmeter employing a propagation time difference method which can easily detect an abnormality of an ultrasonic absorber for suppressing a pipe propagation wave. The ultrasonic flowmeter (1) comprises: a first ultrasonic transceiver unit (20A) installed on an outer circumference of an upstream side of a pipe (A) in which fluid flows; a second ultrasonic transceiver unit (20B) installed on an outer circumference of a downstream side of the pipe (A); a flow rate calculation unit (55) to calculate a flow rate of the fluid based on time taken for the second ultrasonic transceiver unit (20B) to receive an ultrasonic wave transmitted from the first ultrasonic transceiver unit (20A) and time taken for the first ultrasonic transceiver unit (20A) to receive an ultrasonic wave transmitted from the second ultrasonic transceiver unit (20B); an ultrasonic absorber (10) installed on the outer circumference of the pipe (A) to absorb a pipe propagation wave of the ultrasonic wave; and an abnormality determination unit (63) to determine an abnormality in the ultrasonic absorber (10) if a difference between or a ratio of a value indicating an attenuation state of a specific pipe propagation wave and a reference value exceeds a threshold value.