Detailed explanation of pressure sensor function o

Detailed explanation of the function of excavator pressure sensor

force sensor is the most widely used sensor. It is the general term for detecting the force energy between all substances such as gas, liquid, solid, etc., and also includes a pressure gauge that measures higher than atmospheric pressure and a vacuum gauge that measures lower than atmospheric pressure. There are many kinds of force sensors. The traditional measurement method is to use the deformation and displacement of elastic elements to express, but it is bulky, bulky and output nonlinear. With the development of microelectronics technology, using the piezoresistive effect and good elasticity of semiconductor materials, semiconductor force sensors have been developed, mainly including silicon piezoresistive and capacitive. They have the advantages of small size, light weight and high sensitivity, so semiconductor force sensors have been widely used. When a semiconductor is stressed upward on a certain crystal, its resistivity will change to a certain extent. This relationship between the change of conductor resistivity and stress is called semiconductor piezoresistive effect. The mechanical quantity sensor made by using this effect is called piezoresistive force sensor. It has two types: one is the sensor made by pasting semiconductor strain gauge on elastic element, which is called adhesive piezoresistive sensor, and the other is the diffusion resistance made by integrated circuit process on the substrate of semiconductor material, The sensor that makes the strain gauge and the silicon substrate form a whole is called the diffusion piezoresistive sensor

the adhesive piezoresistive force sensor is connected into a full bridge form by four semiconductor strain gauges and pasted on the elastic element with adhesive 3 The composition of the tensile range of the experimental material has a high strain sensitivity coefficient, generally 20 ~ 200, so the output is high, and the output sensitivity is generally 15 ~ 0mv/v, but it is prone to zero drift and creep. At the same time, it also has the influence of temperature drift caused by the thermal expansion of semiconductor strain gauge and elastic element. Diffusion piezoresistive force sensors are mostly made of monocrystalline silicon and semiconductor planar technology. Generally, n-type silicon is used as the substrate, and boron atoms are diffused into the n-type silicon substrate material along the given crystal direction by oxidation, diffusion and other processes to form a p-type diffusion layer

as a result, the boron diffusion region forms a strain resistance and forms a whole with the substrate. When it is subjected to pressure, the strain resistance changes, thereby changing the output

piezoresistive force sensor must do a hydraulic test on plastic water supply pipeline. The sensor has the characteristics of high sensitivity, high precision, small volume, light weight, high working frequency, simple structure, reliable operation, long service life, etc

capacitive force sensors have been developed rapidly recently. The core part of this sensor is the pressure sensitive capacitor. The capacitance of a force sensitive capacitor is determined by the electrode area and the distance between the two electrodes

when there is a pressure difference between the two sides of the silicon diaphragm, the silicon diaphragm will deform, and the spacing between the capacitor plates will change, resulting in the change of capacitance. In this way, the capacitance change is related to the pressure difference, so it can be used as a force sensor. Compared with piezoresistive force sensor, it has the characteristics of high sensitivity, good temperature stability and large pressure range