How a Clamp-On Ultrasonic Flow Meter Works (Transit Time)
Tell us the liquid, pipe size and flow range — we confirm whether a transit-time clamp-on meter fits your application and which model.
How does an ultrasonic flow meter work? This 56-second animation shows the transit-time method: two clamp-on transducers send pulses with and against the flow, and the arrival-time difference is proportional to flow velocity; multiplied by the pipe inner area it gives the flow rate.
Chapters
Key points
- Two transducers clamp on the outside of the pipe; nothing touches the liquid and the pipe is not cut.
- A pulse travelling with the flow arrives slightly earlier than one travelling against it.
- The time difference is proportional to flow velocity; velocity × pipe inner area = flow rate.
- Setup needs pipe size, wall thickness, material and liquid; the meter then calculates the transducer spacing.
Transcript
How does a clamp-on meter measure flow in a closed pipe?
Two ultrasonic transducers are clamped on the outside of the pipe. Nothing touches the liquid, and the pipe is never cut.
Transducer one sends a pulse to transducer two, with the flow. Then transducer two sends one back, against the flow. The pulse with the flow arrives slightly sooner.
The time difference is proportional to the flow velocity. Multiplied by the inner area of the pipe, it gives the flow rate.
To set up, enter the pipe size, wall thickness, material and liquid. The meter then calculates the transducer spacing.
SEGMENsensor clamp-on flow meters cover DN10 to DN5000, depending on the model. Learn more at segmensensor.com.