Venturi Meter

A Venturi meter is basically a type of flow meter with a specially designed tube, used to measure the flow velocity of liquids especially highly viscous liquids. It is one of the most accurate means of measuring the flow. Just like Electromagnetic Flow meter, it has no pressure drop (head loss) hence is very useful in places where pressure drop should be minimal and where a greater emphasis is laid on the highest accuracy achievable.
When a fluid, whose flowrate is to be determined, is passed through a Venturi meter, there is a drop in the pressure between the Inlet section and Cylindrical Throat of Venturi meter. The drop in pressure can be measured using a differential pressure measuring instrument. Since this differential pressure is in direct proportion to the flowrate as per the Bernoulli's Equation hence the differential pressure instrument can be configured to display flowrate instead of showing differential pressure.