Study on quartz tuning fork resonator as micro temperature

Abstract

A miniature digital temperature sensor with the ZY cut quartz crystal tuning fork resonators was developed. The quartz crystal tuning fork resonators have the characteristic that the resonance frequency changes by the external temperature, which achieves high sensitivity and high-speed response and frequency stability by a sample structure. The quartz crystal tuning fork resonators are square cross section tuning forks whose arms are vibrating in flexure-mode with clamped-free boundary conditions. We designed and analyzed the thermo characteristics of the quartz crystal tuning fork resonator by theory and finite element method. The design and implement of a FPGA-based frequency measurement system for quartz crystal tuning fork temperature sensor is proposed. Using different design technique a bandwidth of 40 MHz and a resolution of 0.02 Hz is achieved. The experimental results shown that a temperature accuracy of 0.05 °C and a resolution of 0.02 °C within temperature range from −10 °C to 150 °C.