石英谐振力传感器的温度自测及温度补偿

Dual-frequency Self Temperature Sensing and Temperature Compensation of Quartz Resonator Force Sensor

石英谐振器的基频和 3次泛音频率都是力和温度的函数 ,利用二者各阶温度系数除一阶外均相同的特性 ,基频的 3倍频与 3次泛音的差频是温度的线性函数并且与力无关 ,因此测量差频可以实现力传感器的温度自测和温度补偿。与采用分立的温度传感器相比 ,该方法消除了由于温度传感器和谐振器热惯性和空间位置不同引起的测温误差 ,提高了动态温度过程中的补偿精度。

This paper describes a novel method to realize the temperature compensation of AT cut quartz crystal resonator force sensors based on dual frequency oscillating.The fundamental and the third overtone frequencies are both force and temperature cross sensitive.The normalized beat frequency between the third overtone frequency and 3 times of the fundamental frequency is almost linear to the temperature changes and is force independent.By stimulating the dual frequencies simultaneously,the temperature changes can be obtained by the beat frequency.This new method can eliminate the thermal lag due to the difference in thermal time constants of the resonator and the thermistor,and can overcome the limitation of temperature gradient.The implementation of the self temperature sensing method and temperature compensation are described and experimental data are discussed.