Design And Implementation Of Large Range And High Precision Of Smart Digital Pressure Gauge

This thesis mainly discusses a kind of high precision intelligent digital pressure gauge which used in a wide range.The digital pressure gauge can be used in industrial production in measuring the pressure of liquid and gas. When the range span of pressure is large, the linearity of the pressure sensor is deteriorated. The accuracy in entire range can’t be guaranteed. Use Multi-point calibration to make sure the accuracy don’t reduced. This thesis designed a pressure gauge which the pressure range is: 0-60 MPA. One in 0 and 1 MPA range the accuracy can reach 0.2%, in 1 to60 MPA range the accuracy can reach 0.5%.Use the multi-point calibration technology to calibrate sensor input/output curve.The intelligent digital pressure gauge have several parts including the pressure acquisition part, signal conditioning part, key input module, liquid crystal display module, the microprocessor STM8L152C6. The pressure signal acquisition part uses ceramic pressure sensor. Ceramic pressure sensor has high accuracy, stability and signal output merit. At the same time ceramic pressure sensor has good corrosion resistance and a series of performance. Signal conditioning circuit uses MCP6002 chip as an amplifier, a weak difference signal can effectively be enlarged. The microprocessor chip STM8L152C6 has 48 pins, built-in LCD driver functions, 12 AD sampling module reduce the total costs and so on.This task of intelligent digital pressure gauge can realize the function of the following: real-time acquisition and display of pressure. Use WIFI to upload pressure data to the PC machine. The data display and then stored in a SQL database.You can set a period of time to check the record pressure value.