Flow measurement

Flow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. The common types of flowmeters with industrial applications are listed below:

• a) Obstruction type (differential pressure or variable area)
• b) Inferential (turbine type)

• c) Electromagnetic
• d) Positive-displacement flowmeters, which accumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow.
• e) Fluid dynamic (vortex shedding)
• f) Anemometer
• g) Ultrasonic
• h) Mass flowmeter (Coriolis force).
Flow measurement methods other than positive-displacement flowmeters rely on forces produced by the flowing stream as it overcomes a known constriction, to indirectly calculate flow. Flow may be measured by measuring the velocity of fluid over a known area. For very large flows, tracer methods may be used to deduce the flow rate from the change in concentration of a dye or radioisotope.