Temperature sensor based on quartz tuning-fork resonator

Abstract

A miniature thermo-sensitive quartz tuning-fork resonator (TSQFR), working in the flexural vibration mode as a temperature sensor, has been expressed. This type of resonator, designed with a new doubly rotated ZYtw-cut, the rotation angle /spl Phi/ and /spl theta/ of which must be in the range 110/spl deg//spl plusmn/1/spl deg/ and 14/spl deg//spl plusmn/2/spl deg/, shows nearly a linear response with a sensitivity between 53 ppm/spl deg/C/sup -1/ and 59 ppm/spl deg/C/sup -1/ with temperature range from -30 to 150/spl deg/C. Precise temperature versus frequency analyses of the resonators has been carried out and a least mean squared (LMS) curve fitting algorithm can be used to compute the temperature values quantitatively. Experimentally, the sensor showed an accuracy of 0.05/spl deg/C with a resolution of 10/sup -3//spl deg/C for a 2 s response time.