Determination of viscosity and dielectric constant of liquids using the equivalent circuit method using a resonator with a lateral electric field

The paper presents a method for determining the viscosity and permittivity of a liquid using the equivalent circuit method. The parameters of the Mason equivalent circuit were found for a piezoelectric resonator with a lateral electric field made of PZT-19 ceramics. The frequency dependences of the real and imaginary parts of the electrical impedance of a resonator loaded with liquid samples with different viscosity and permittivity were measured. The fitting of the theoretical frequency dependences of the real and imaginary parts of the electrical impedance of a resonator loaded with mixtures of “water - isopropyl alcohol” and “water - glycerin” to the measured dependences was carried out. As the result the dependence of the permittivity of the liquid on the additional capacitance (determined from the Mason scheme) and the dependence of the shear fluid viscosity on the imaginary part of the mechanical impedance of the fluid load (determined from the Mason scheme) were built. These dependences can be used as calibration curves to determine dielectric constant and viscosity.