The Design And Realization Of Temperature Drift Compensation Module For Diffusion Silicon Pressure Transmitter

The diffusion silicon pressure transmitter is widely used because of its significant advantages such as fast dynamic response and high measuring accuracy. But it is easy to produce temperature drift, which is seriously affecting its stability and accuracy characteristics. Mainly for this defect, this paper designed an intelligent temperature drift compensation module.Firstly, the paper discussed operating characteristics of the diffused silicon pressure transmitter and analyzed the reasons for the temperature drift, then puts forward several compensative algorithms for the diffusion silicon pressure transducer’s temperature drift. Secondly, it describes the composition of hardware system. I tested the zero drift at different temperatures combined with a constant temperature incubator through experiments, then use a constant temperature water tank measured the outputs at different temperatures when the transmitter in different liquid levels. I analyzed the test data combined with the compensative algorithms mentioned earlier and then choose piecewise linear interpolation as the algorithm in my design. Selected PIC16F877A single chip as control chip and implemented the algorithm through the MCU C programming language. The pressure transmitter and temperature transmitter collect pressure and temperature signals separately and input the signals into the single chip microcontroller, then run the compensative algorithm after A/D conversion and output the compensated pressure value, finally communicate with the host computer through MCU RS485communication interface.By analyzing the test data before and after compensation we can find that the temperature compensation module can completely eliminate the zero drift. The accuracy of the pressure transducer has been improved, furthermore, the design has a low cost and a higher reliability.