DE3225690

An ultrasonic device for measuring the delivery of fluid through a conduit. A pair of electroacoustic transducers are arranged in the wall of the pipe forming the conduit in a mutually confronting relationship along an axis inclined relative to the conduit axis. Each transducer is able to convert an electric signal of predetermined frequency into an ultrasonic wave which propagates through the fluid toward the confronting transducer. After a predetermined interval of transmission, each transducer receives the transmitted wave and converts it to an electric signal. A collimator is disposed in the path of the fluid upstream of the transducers. An oscillator outputs electrical signals of predetermined frequency to the transducers. In response to receipt of the ultrasonic waves, the transducers send electric signals to processing circuitry which detects the phase difference between the ultrasonic waves received by the respective transducers and correlates the phase difference with the delivery of fluid in the conduit.