Ultrasonic flow meters are best suited for flow measurement of fluids in pressure pipes as well as in channels and semi-filled pipes.

Measuring principle (transit time)
Ultrasonic signals are alternately sent in and against the flow direction. Ultrasonic energy bursts are transmitted and received via well-defined paths across the flow stream. The velocity of the flow is accurately measured by the difference in the arrival times of signals from the upstream and downstream transducers. The transit time difference (Δt = t2/1 – t1/2) determines the average flow velocity.