On the Robust Measurement of Resonant Frequency and Quality Factor of Damped Resonating Sensors

Resonating sensors are commonly used for various measurement tasks, e. g., as microbalances as well as for viscosity and density measurements of viscous or viscoelastic media. The resonance frequency and the quality (Q) factor of these sensors is typically determined electrically and can be disturbed by parasitic effects caused by the sensor or the interface circuit. To achieve high accuracy the resonator behavior is recorded in vicinity of the resonant frequency and the desired parameters are calculated from this spectral information. For the determination of resonance frequency and Q-factor the use of estimator algorithms which are insensitive to parasitic effects is preferable. We demonstrate advantageous estimator strategies and assess the performance of the specific estimators by evaluating the spectral data of a strongly damped resonant sensor evaluated with two different analyzer instruments.