Patent ID: 7712382

Claim:
A doppler ultrasonic flowmeter comprising: an ultrasonic transmission member for casting ultrasonic pulses with a predetermined frequency onto the fluid within a fluid tube, which is to be measured, along a measurement line from an ultrasonic transducer; a flow-speed distribution measurement unit for receiving ultrasonic echoes reflected from the measurement region due to ultrasonic pulses cast onto the fluid to be measured so as to measure the flow-speed distribution of the fluid to be measured in the measurement region; a flow measurement unit for measuring the flow of the fluid to be measured in the measurement region based upon the flow-speed distribution of the fluid to be measured; and a transducer position adjusting mechanism for adjusting the relative position of a pair of ultrasonic transducers serving as the ultrasonic transmission member, i.e., a first transducer and a second transducer, which are disposed away one from another along the axial direction of a fluid tube, wherein said transducer position adjusting mechanism has a configuration for adjusting the position of the pair of transducers while maintaining the positional relation thereof such that the ultrasonic pulse beam cast from the first transducer and the ultrasonic pulse beam cast from the second transducer are orthogonal one to another in the measurement region within the fluid tube.