Temperature-frequency characteristics of quartz tuning fork for temperature sensing

A quartz tuning fork (QTF) micro-resonant temperature sensor which employs the shifting frequency corresponding to temperature is developed for high performance temperature measurement. The sensor is designed by the theoretical analysis, and the finite element simulation is employed to optimize the structure parameters. Micromachining technology is adopted in the fabrication of the QTF resonator using photolithography and etching technology. Performances of the QTF temperature sensor prototypes are experimentally investigated. Experimental results show that the resonance frequency of the QTF temperature sensor is approximately 36.545 kHz and the sensitivity is -1.9 Hz/℃ in the operating range of -20-100 ℃, with a non-linearity less than 0.18% and a hysteresis of 0.02%, which are in good agreement with analytical calculation results. Due to the excellent performances such as high accuracy, high sensitivity, low power and low cost, this QTF temperature sensor provides a commendable solution for high performance temperature measurement.