Patent ID: 7077012

Claim:
A wedge unit used for an ultrasonic Doppler flow meter, being mounted on the outer wall of a pipe in which a fluid flows, supplying an ultrasonic wave to the fluid, receives the reflected wave and supplies the reflected wave to a flow rate calculation unit, comprising: a wedge with one surface thereof being mounted on a part of the outer circumference of the pipe and on another surface thereof being equipped with an ultrasonic oscillator that generates the ultrasonic wave in response to an electric signal and receives the reflected wave; and an ultrasonic wave attenuation unit being mounted on the outer circumference of the pipe; wherein the ultrasonic wave attenuation unit is configured to be in contact with a position where an ultrasonic wave injected by the ultrasonic oscillator into the pipe by way of the wedge first reaches the outer wall of the pipe after being reflected by the inner wall of the pipe.