Transit time ultrasonic flowmeters

Transit time flowmeters are used for measuring clean or nearly clean fluids and natural gas pipe systems. It is important there are no air bubbles and that the solid content does not exceed 5 percent.

Principle of operations

Pair of transducers are placed on the pipe wall, each having its own transmitter and receiver, one for the upstream and the other for the downstream. The time for sound waves to travel from the upstream transducer to the downstream transducer is shorter than the time it requires for the same sound waves to travel from the downstream to the upstream. Acoustic waves travel time difference is directly proportional to the flow velocity.