Design, Development and Testing of Quartz Tuning Fork Temperature Sensor

In this paper, a low cost quartz tuning fork temperature sensor adopting H-shaped tuning fork resonator to address miniaturization, high resolution and high stability has been designed, developed and tested. The quartz tuning temperature sensor is designed vibrating in flexural mode with a new thermo-sensitive cut. The quartz tuning fork temperature sensor consists of two prongs connected at one end of crystalline quartz plate with thin-film metal electrodes deposited on the faces, which is used to produce vibration in response to alternating voltages and detecting the resonance frequency in the meantime. When an external temperature is change, there is a shift in its natural frequency. Based on this principle, a resonant thermometer is designed. Finite element method is used to analyze the vibratory modes and optimize the structure. The whole structure is 500 mu m thickness, the length of tuning fork arm is 3076 mu m and the width of tuning fork arm is 600 mu m, the frequency of tuning fork is about 37kHz with a sensitivity of rough 85 ppm/degrees C. The experimental results shown that a temperature accuracy of 0.01 degrees C and a resolution of 0.005 degrees C within temperature range from 0 degrees C to 100 degrees C. All these research are helpful to design satisfactory performance of the sensor for temperature measurement.