Abstract
This paper describes the development of temperature sensor based on a temperature-sensitive quartz “tuning fork” resonator. The resonator was fabricated using photolithography and anisotropic etching. The optimum cut of the crystal and optimum resonator orientation on the wafer were determined-taking into account the anisotropic etching properties of the crystal-to give a large temperature coefficient of frequency consistent with small equivalent series resistance.
The tuning fork temperature sensor operates over a wide range of temperature (from 4.2K to 250°C). After the temperature sensor was cycled between 0°C and 4.2K, hysteresis in the temperature characteristic was only within 0.005K at 0°C. The time constant of thermal response is about 0.9s. The quartz temperature sensor is quite compact-it is mounted in a hermetic case only 3mm in diameter.
