The Research On Micro Differential Pressure Transmitter And Temperature Compensation Implementation

With the development of industry, micro pressure of gas, steam andliquid needs to be measured in many industry situations. The instrumentwhich is used to measure these micro pressures is called micro differentialpressure transmitter. In the market today, there are micro pressuretransmitters mainly containing controllable silicon sensor. But in industry,capacitive transducers are mostly used. Compared with controllable siliconsensor, the capacitive transducer has better performance, such as highertemperature stability, higher ability of dynamic pressure and so on. But thecompany which can produce the capacitive sensor used in pressuretransmitter is less, and less research has done on the capacitive differentialpressure transmitter. The related products are mainly imported, the cost isvery high.The paper mainly studied the transmitter with capacitance sensor. Thetransmitter was studied based on the capacitance sensor and was completedby sensor structure improvement, hardware anti-interference design, andtemperature compensation. The article studied the effect of suspensiondesign to the performance of capacitive sensor. In this paper, thecharacteristics of the sensor were analyzed when it is in micro pressuresituation. This design was based on bilinear interpolation method andcompared several curve fitting methods and neural network analysismethods. The temperature compensation model was established byapplying measured AD value and temperature value as pixels, combiningchange rule of pressure side from the point of image processing. This canbeen considered as a new research direction of temperature compensation. In the design, temperature compensation time was effectively reduced;temperature drift and nonlinear change problems were solved by applyingthe mature image processing technology.0～1kPa pressure measurementof gas, steam and liquid was realized and the measurement error wascontrolled in the range of less than plus or minus0.1%to0.01%. Thedesign is verified by the test results.A kind of capacitance sensor based micro differential pressuretransmitter used in industry was designed. This design provides a researchmethod for micro differential pressure transmitter, give suggestions forsubsequent research and the direction of improvement.