Ultrasonic flowmeters operate using the transit-time differential method. The Transit-time differential measurement is based on a simple physical fact. Imagine two canoes crossing a river on the same diagonal line, one with the flow and the other against the flow. The canoe moving with the flow needs much less time to reach the opposite bank.
Ultrasonic waves behave exactly the same way. A sound wave travelling in the direction of flow of the product is propagated at a faster rate than one travelling against the flow (vAB > vBA).
Transit times tAB and tBA are measured continuously. The difference (tBA – tAB) in time travelled by the two ultrasonic waves is directly proportional to the mean flow velocity (vm).
- tAB is Time required for ultrasonic wave to travel from Sensor A to B sensor
- tBA is Time required for ultrasonic wave to travel from Sensor B to A sensor
- Transit Time Flow Meter Advantages and Disadvantages
- Transit Time Flowmeter Principle
- Coriolis Mass Flowmeter Theory
- Area Velocity Flow Meter Principle
- What is a Ultrasonic flow meter ?
- Guided Wave Radar Level Sensor Pressure and Temperature Effects
- Flow Instruments – Selection, Principle & Application
- Difference between Transit time and Doppler Ultrasonic Flow Meter
- Basics of Ultrasonic Flowmeters & Factors Affecting its Performance
- Ultrasonic Level Transmitter Working Principle