高精度电容式压力传感器测量方法

Measurement method of high-precision capacitive pressure sensor

提出了一种高精度、低成本的电容式压力传感器的测量方法。用RC振荡器将电容式传感元件的变化调制为时变频率信号,用SSP1492芯片测量该频率变化量,并送入C8051F021单片机,用高阶多项式完成频率变化到压力变化的解算,实现了高精度压力测量。实验结果显示:该方法用于电容式压力传感器的测量精度优于0.02%FS。

A measurement approach for high-precision and low cost capacitive pressure sensor is presented. ARC oscillate circuit is used to modulate capacitive variance to frequency signal, which is measured by SSP1492. A C8051F021 MCU is employed to process the compute task from frequency variance to pressure variance by high- order polynomial so that high-precision pressure measurement is achieved. Experimental results show that the measurement precision by the proposed method can achieve 0.02 % FS.