Pressure variable sent device is industrial application in the most common of a sensor, its widely application Yu various industrial control environment, involved water hydropower, and railway traffic, and intelligent building, and production control, and aviation space, and military, and petrochemical, and wells, and power, and ship, and machine, and pipeline, many industry, pressure variable sent device of type roughly for following several: resistance strain tablets pressure variable sent device, and semiconductor strain tablets pressure variable sent device, and pressure resistance type pressure variable sent device, and inductance type pressure variable sent device, and capacitor type pressure variable sent device, and Resonance type pressure transmitter and a capacitive acceleration sensor. But the most widely used is a Piezoresistive type pressure transmitter, it has a very low price and higher precision and better linearity. Following our main introduce this type of sensor.
1, pressure transmitters
When the understanding of Piezoresistive pressure transducer, we first meet resistance strain gage this component. Strain is a strain on the EUT sensitive device change into an electrical signal. Piezoresistive strain it is one of the major components of the transmitter. Strain gauge most widely used metal strain gauge and semiconductor strain gauges in two ways. Metal strain gauge and a filamentous strain gauges and metal foil strain gauges in two ways. Usually strain through a special stick and closely bonding agent in the mechanical strain on the matrix, stress when stress occurs when the matrix, strain deformation, strain gage resistance value changes, so as to make change in the voltage across the resistor.
2, of diffused-Silicon pressure transmitter
Directly measured media pressure acting on the diaphragm of the sensor (stainless steel or ceramic), with medium pressure proportional to the displacement of the diaphragm, the sensor resistance value changes, and this change was detected by electronic circuits, and convert the output corresponding to a standard measurement of the pressure signal.
3, capacitance-type pressure transmitter
Ceramic capacitive sensor is suitable for normal or corrosive media measurement, such as gas, liquid or gas, but does not tend to precipitate, Crystal or recommendation of stiffening material. Should be used to hold liquid level measurement, water, water, diesel fuel and oil on board.
4, piezoelectric pressure sensor
Piezoelectric sensor using Piezoelectric materials include quartz, potassium sodium tartrate and monobasic amine. Quartz (silicon dioxide) is a natural Crystal, piezoelectric effect are found in the Crystal, at a certain temperature range, piezoelectric nature has always existed, but the temperature exceeds this range, piezoelectric properties disappear completely (this temperature is called the "Curie point"). Due to the stress of changing electric field on small (also said low piezoelectric coefficients), was gradually replaced with a piezoelectric crystal of Quartz. Potassium sodium tartrate is a great deal of pressure sensitivity and piezoelectric coefficients, but it can only be at room temperature and low humidity environment application. Monobasic amine belongs to the artificial crystals, can withstand high temperatures and high humidity, so it has a wide range of applications. Now the piezoelectric effect also on polycrystalline, as now of piezoelectric ceramics include barium titanate piezoelectric ceramics, PZT, niobate piezoelectric ceramics piezoelectric ceramics, niobium, lead magnesium and more.
5, ceramic pressure transducer
Principle anti-corrosion of pressure variable sent device no liquid of passed, pressure directly role in ceramic diaphragm of Qian surface, makes diaphragm produced tiny of deformation, thick film resistance printing in ceramic diaphragm of back, connection into a huisi power bridge (closed bridge), due to pressure sensitive resistance of pressure resistance effect, makes bridge produced a and pressure into is proportional to the of height linear, and and incentive voltage also into is proportional to the of voltage signal, standard of signal according to pressure power drive of different calibration for 2.0/3.0/3.3 mV/V,, And strain sensors are compatible. Laser calibration, the sensor has a high temperature and time stability, 0~70℃ sensor with temperature compensation and direct contact with most of the media.
Ceramic is a recognized form of high elasticity, resistance to corrosion, abrasion, shock and vibration-resistant materials. Ceramic thermal stability characteristics and its thick film resistors can be made up to its operating temperature range-40~135℃, and it has advantages of high accuracy, high stability. Electrical insulation degree >2kV, the output signal is strong, long-term stability. High features, low price development of the ceramic sensor pressure transmitter.