A flow sensor is a device for sensing the rate of fluid flow. Typically a flow sensor is the sensing element used in a flow meter, or flow logger, to record the flow of fluids. In fluid dynamics, the rate of fluid flow is the volume of fluid which passes through a given area per unit time. ... Distinguish from censure and censer and censor. ... Flow measurement is the quantification of bulk fluid or gas movement. ... A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ...

There are various kinds of flow meters, including some that have a vane that is pushed by the fluid, and can drive a rotary potentiometer, or similar device.

Other flow meters use a displacement piston, pushing it against a spring.

Flow meters are related to devices called velocimeters that measure velocity of fluids flowing through them. Laser-based interferometry is often used for air flow measurement, but for liquids, it is often easier to measure the flow. Another approach is Doppler-based methods for flow measurement. Hall effect sensors may also be used, on a flapper valve, or vane, to sense the position of the vane, as displaced by fluid flow. Velocimetry is the measurement of the velocity of fluids, as often used to solve fluid dynamics problems, or to study fluid networks, as well as in industrial and process control applications, or in the creation of new kinds of fluid flow sensors. ... In physics, velocity is defined as the rate of change of displacement or the rate of displacement. ... It has been suggested that Optical interferometry be merged into this article or section. ... Look up air in Wiktionary, the free dictionary. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The magnetic piston (1) in this pneumatic cylinder will cause the Hall effect sensors (2 and 3) mounted on its outer wall to activate when it is fully retracted or extended. ...

A fluid dynamics problem is easily solved (especially in non-compressible fluids) by knowing the flow at all nodes in a network. Alternatively, pressure sensors can be placed at each node, and the fluid network can be solved by knowing the pressure at every node. Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... Digital air pressure sensor A pressure sensor measures the pressure, typically of gases or fluids. ...

These two situations are analogous to knowing the currents or knowing the currents at every node (noncompressible fluid being conserved in the same manner as Kirchoff's current or voltage laws, in which conservation of fluid is analogous to conservation of electrons in a circuit). In electricity, current refers to electric current, which is the flow of electric charge. ... In electricity, current refers to electric current, which is the flow of electric charge. ... e- redirects here. ...

Flow meters generally cost more than pressure sensors, so it is often more economical to solve a fluid dynamics network monitoring problem by way of pressure sensors, than to use flow meters.

See also

• Flow measurement