Temperature-insensitive dual-mode resonant sensors - a review

Dual mode excitation of resonators allows the highly accurate measurement of, and compensation for, the effects of temperature, pressure, etc., by means of frequency measurements alone. Frequency can be measured with far higher accuracy than any other quantity. In dual mode excitation, the two excited modes occupy the same volume of quartz, thereby allowing the resonator to sense two measurands simultaneously, e.g., pressure and temperature. This paper reviews the dual-mode technique and its sensor applications.