Abstract: Ultrasonic flow meter of the clamp-on type for the measurement of the flow rate of a liquid in a pipeline, provided with two piezoelectric transmitting-receiving transducers, each accommodated in a housing, which are clamped at both sides of the pipeline axially offset with respect to each other thereon and which alternately transmit ultrasonic pulses into the pipeline and receive them therefrom in order to determine the flow rate from the transit time of the source pulses in the upstream and downstream direction. The transducers each consist of a row of adjacent subtransducers, the pulse emission face of which row is coupled over its entire length in the axial direction to the pipe wall.

Abstract: A device for measuring the flow velocity of fluids including at least one pair of electro-acoustic transducers at the ends of a measurement path, said pair of transducers simultaneously transmitting acoustic pulses and receiving the same at first and second times, a transmission circuit, a receiving circuit, an integration circuit having an integration capacitor, the charge and discharge circuits of which are controlled by the transit times of the acoustic pulses, the starting point of which is sharply defined by a control circuit of both transducers.