Answer / manoj kumar

There are several ways to measure the flow of fluid & gas
like magnetic flow meter, mass flow meter, based on
measurement of differential pressure like venturi, orifice
etc, turbine flow meter, positive displacement flow meter,
vortex flow meter.
Measurement of flow with the help of orifice is based on
the measurement of differential pressure across the orifice
plate. Tappings are either on the supporting flange or at D
& D/2 m away for upstream and downstream of the orifice
respectively where D id Pipe diameter in which plate is
installed.
Not all the transmitters are square root.Those transmitters
which are based on differential pressure are square root.
We can use square root at the transmitter itself or we can
make the calculation in the DCS/PLC program.
Since Q(flow) is directly proportional to square root of
the differential pressure we do the square root extraction
to measure the flow.

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