The main function of the sensor to measure pressure is a measurement of pressure on the inlet to the sensor and the further conversion to digital, or electric. Structurally sensors consist of a sensor and electronic block. The sensor reads the pressure sensor and then converts the signal into a physical quantity, which is then entered into the electronics of the converter. Electronic unit converts the signal into digital, such as 4-20mA. In this case, sensor calibration is that the minimal value of the signal is 4 mA, maximum 20 mA, respectively, the electric signal output from the sensor corresponds to a range of pressure, which is designed sensor. Pressure sensors with digital signal has a large selection of performance sensors, such as capacitive, strings, inductive, piezoresistive, magnetic, strain, etc. (As opposed to foursquare). Consider some of them: datchikiEmkostnye Capacitive sensors consist of a tank and two plates. The distance between them is filled with an insulating medium.
In most of these pressure sensors manufacturers use Silicone oil or inert filler. The diaphragm, located between the plates bend under the influence of the medium. Should take into account the fact that when measuring the pressure on the side low pressure diaphragm pressure is applied. In measuring the absolute pressure applied reference pressure on the membrane. Next, determine the angle of the plate aperture and send a signal to the electronics unit. Piezoresistive datchikiGlavnoy feature of piezoresistive sensors is very pezorezistor. It is a semiconductor whose resistance changes with strain or tension. In this case, pressure is transmitted through the liquid filling from the diaphragm to pezorezistoru.
Further, this resistance value goes to the electronic unit, which converts the signal into electrical energy. Inductive sensors datchikiInduktsionnye based on the transfer of magnetic fields on the body to another body, not in contact with the first. In other words – constructive induction sensor has an iron core, a coil of wire through which passes a current. Core connected to the diaphragm when the pressure is changing position relative to the very core of the winding, respectively, changing the inductance coil. The signal is then converted to an electronic unit.