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A pressure sensor measures the pressure, typically of fluids. Pressure, of course, is an expression of the force required to stop a fluid from expanding, and is usually stated in terms of force per unit area. A pressure sensor generates a signal related to the pressure imposed. Typically, such a signal is electrical, but it might also include additional means, such as optic signals, visual signals and/or auditory signals. Pressure sensors have particular utility for monitoring the pressure in a fluid network. As compared with flow sensors, pressure sensors often require less cost to achieve a similar result. Pressure sensors are often fabricated using thin membranes that flex under pressure. Some pressure sensors function in a binary manner, i.e., when pressure is applied to a pressure sensor, the sensor acts to complete or break an electical circuit. Some speed cameras use them.
Types of fluid pressure measurements Absolute Pressure Absolute pressure is expressed relative to a vacuum (i.e., no pressure). Gauge Pressure Gauge pressure is expressed relative to atmospheric pressure. Atmospheric pressure is about 100kPa (14.7 psi) at sea level. A vented gauge pressure sensor has one port uncovered so it may operate to sense the local atmospheric pressure. A sealed gauge pressure sensor has one port sealed at manufacture at average atmospheric pressure. Differential Pressure A differential pressure sensor expresses the difference in pressure between two ports on the device. Applications http://xtronics.com/reference/xprimer.htm | ||||||||
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