Diffusion silicon pressure transmitter is a typical and commonly used pressure measuring instrument, which consists of two parts: one is the detection element, i.e. the diffusion cinnamon piezoresistive pressure sensor, which is responsible for converting the physical quantity pressure signal to the voltage signal in the work site; the other is the signal processing circuit with multiple functions, which is responsible for converting the physical quantity pressure signal to the voltage signal. The output voltage signal of the sensor is transformed by amplification and two-wire signal processing, and then the standard signal is output. Because of its high measurement accuracy and fast dynamic response, it is widely used in all walks of life.
Based on the piezoresistive effect of single crystal cinnamon, an elastic component is fabricated by advanced processing technology in a specific direction. Four strain resistors with equal resistance are fabricated by integrated circuit technology in their proper positions and connected to the Wheatstone Bridge. When a constant voltage (current) is applied to the bridge, when there is pressure (differential pressure) on the elastic element, the transmitter outputs a voltage signal linearly proportional to the pressure given by the medium, and then amplifies the voltage signal through an electronic circuit and converts it into a standard two-wire signal. According to its working principle, the main source of temperature drift is the temperature drift of the sensor part. Next, the working principle and characteristics of the sensor part of the pressure transmitter will be analyzed.