Viscosity measurement cell utilizing electrodynamic-acoustic resonator sensors: Issues and improvements

Miniaturized viscosity sensors operating at frequencies in the KHz-range offer portability and results comparable to existing lab viscometers. In this paper we will briefly describe a viscosity measurement cell utilizing electrodynamic-acoustic resonator sensors and provide a modified design with interchangeable resonator cards, which allow for ease of maintenance of the device and provides higher measurement repeatability. Some basic experiments made with the new resonator cards are presented, which show the clear dependence of the resonance frequency and Q factor on viscosity. In addition, an approach is taken to optimize the magnetic circuit for the measurement cell using finite element simulations and experiments. A temperature dependence comparison is made between straight beam resonators and S shaped (Meander) beam resonators the result of which is the adoption of the S shaped beam design for further investigation. Finally the data processing approach using a curve fitting function designed for low quality factors is briefly described.