Pressure sensors are made of piezoelectric effect, that is, the piezoelectric sensors. We know that the crystal is anisotropic and the amorphous is isotropic. Some crystal media, when subjected to mechanical forces in a certain direction of deformation occurs, it produced a polarization effect. Then pressure sensors are developed by scientists based on this effect.
Quartz, Ammonium dihydrogen phosphate and Sodium potassium tartrate are the main piezoelectric materials used in piezoelectric sensors. The quartz (silica) is a natural crystal, the temperature control in a certain range, stable piezoelectric properties, but once the temperature out of limit, the piezoelectric properties completely disappear. As the the piezoelectric coefficient is relatively low, the quartz is gradually replaced by other piezoelectric crystals. Potassium sodium tartrate has a large piezoelectric sensitivity and piezoelectric coefficient, but it can only be used at room temperature and humidity is relatively low. Dihydrogen phosphate is an artificial crystal, can withstand high temperatures and very high humidity, it has been widely used.
(Types of pressure transmitter display)
Piezoelectric effect is also used in the polycrystalline, such as piezoelectric ceramics, including barium titanate piezoelectric ceramics, PZT, niobate piezoelectric ceramics, lead niobium magnesium lead-acid piezoelectric ceramics, etc.
Piezoelectric effect is the main working principle of piezoelectric sensors, piezoelectric sensors can not be used for static measurement, because only in the loop with an infinite input impedance is saved after the external force after the charge. This the actual situation is not like this, so this determines that the piezoelectric sensor can only measure the dynamic stress.
（Electric connection of pressure transmitter）
Piezoelectric sensors are mainly used in the measurement of acceleration, pressure and force. Piezoelectric acceleration sensor is a commonly used accelerometer. It has the features of simple structure, small size, light weight, long life and excellent. It can also be used in the military industry, for example, to measure the instantaneous change in chamber pressure and the shock pressure of the muzzle in the chamber. It can be used to measure large pressure, and also the small pressure.
Piezoelectric sensors are also widely used in biomedical measurement, for example, ventricular catheter type microphone is made of piezoelectric sensors, because the measurement of dynamic pressure is so common, so the application of piezoelectric sensors is very wide.
Post time: 21-09-21