Ultrasonic flow meter principle

Ultrasonic flow Meter operate applying the transit-time differential method. The Transit-time differential measurement is according to a simple physical truth. Think about two canoes crossing a river on the very same diagonal line, one with the flow along with the other against the flow. The canoe moving with all the flow needs a lot less time to attain the opposite bank.
Ultrasonic waves behave exactly the identical way. A sound wave travelling inside the direction of flow of the item is propagated at a more rapidly rate than one particular 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 imply flow velocity (vm) on the item.
 The volumetric flowrate per unit time would be the product with the imply flow velocity (v<m)></m)>
A liquid item is identified by direct measurement of the transit time of ultrasonic waves. Assuming the identical path length (L), the transit time in water is shorter than in crude oil, for instance.
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