What is a Venturi meter? On what principle does the venturi meter work?

Hint: Venturi Meters are stream estimation instruments which utilize a merging segment of channel to give an expansion in the stream velocity and a comparing pressure drop from which the flow rate can be found.

Complete answer:
They have been for all intents and purpose use for a long time, particularly in the water flexibly industry.
Venturi Meter works on the principle of Bernoulli's standard which expresses that the distinction in pressure made over the hindrance gives the proportion of the liquid stream rate. The stream rate is relative to the square base of the differential pressure.
The venturi meter comprises a straight channel area, a uniting cone shaped gulf segment, a tube-shaped throat and a veering clonelike outlet segment. The throat area is of a little cross segment and it gives tightening to the liquid.
The contraction influences the stream velocity to increment and liquid pressure to drop. The high pressure tap is taken at the delta area and the low pressure tap is situated at the center of the throat. The distinction in pressure among delta and throat is the proportion of stream rate.
The Venturi impact is the decrease in liquid pressure that occurs when a liquid moves through a tightened area (or stifle) of a channel.

Note: In liquid elements, an incompressible liquid's velocity must increment as it goes through a tightening as per the guideline of mass coherence, while its static pressure must diminish as per the standard of protection of mechanical energy (Bernoulli's rule).
Along these lines, any addition in kinetic energy a liquid may accomplish by its expanded velocity through a choking is adjusted by a drop in pressure. By estimating pressure, the stream rate can be resolved, as in different stream estimation gadgets, for example, Venturi meters, Venturi spouts and opening plates.