Implement and Research on the Miniature Quartz Tuning Fork Temperature Sensor

• Main Authors: Jun Xu, Guodong Sun, Jing Ma, Xin Li
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2014-08-01
• Series: Sensors & Transducers
• Subjects: Miniature temperature sensor; Quartz crystal; Tuning fork resonator; Thermal cut; Flexural model; Finite element method.
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/august_2014/Vol_176/P_2252.pdf
• ISSN: 2306-8515; 1726-5479

Temperature sensor using piezoelectric quartz tuning fork resonators have attracted much interest due to their simple structure and potentially high sensitivity. In this paper, we present the fundamental limits of the use of quartz tuning fork (QTF) for temperature sensor. The QTF temperature sensors are tuning fork quartz crystal vibrating in flexural model and optimally designed with a thermal cut, which their frequency is both extremely sensitive to temperature and high linear. The QTF temperature sensor using frequency-based technique which resonance frequency is about 35.6 kHz at 25 °C has the advantage of being immune to amplitude noise in the measurement system and a thermo- sensitivity of roughly -77´10-6/°C. This high thermal sensitivity offers the ability to detect fine changes in temperature. Based on the finite element method, the QTF vibratory modes are analyzed, the size of the QTF beam and the structure of the QTF temperature sensor have optimized and resigned. Experimental results show the QTF temperature sensor with an accuracy of 0.05 °C and a useable resolution of roughly 0.005 °C with a temperature range from 0 °C to 100 °C. This work presents a miniature QTF temperature sensor with a high thermo-sensitivity and small non-linearity.