Resonator sensors-a review

TLDR

Control systems increasingly rely on digital processing, necessitating sensors that provide direct digital outputs, and resonator sensors—whose resonance frequency or phase shifts with the measured parameter—are especially attractive due to their high accuracy, repeatability, low manufacturing cost, and potential for very low power consumption. The review surveys a broad spectrum of resonator sensor designs, from low‑frequency vibrating vanes or tubes to high‑frequency surface acoustic wave devices, covering applications such as liquid or gas density and viscosity, liquid level, mass, mechanical force, and fluid flow measurement.

Abstract

Control systems are becoming increasingly dependent on digital processing and so require sensors able to provide direct digital inputs. Resonator sensors, configured to have a mechanical resonance frequency or relative phase of oscillation dependent on the measured parameter, are a subject of considerable practical interest. The author reviews the wide range of devices which have been proposed and developed, including sensors for liquid or gas density and viscosity, liquid level, mass and mechanical force, and fluid flow rates. Techniques cover the frequency range from audio, for sensors based on vibrating vanes or tubes, to 100 MHz or more for surface acoustic wave devices. Resonator sensors based on single crystal materials such as quartz and silicon are of particular interest because they combine high accuracy and repeatability and low cost of manufacture and potentially very low power consumption.