Piezoelectric-excited membrane for liquids viscosity and mass density measurement

This paper presents a piezoelectric-excited membrane device for rapid measurement of liquids viscosity and density. The working principle of the device is based on membrane's resonant frequency and Q factor responses to the damping effects of a surrounding liquid. The dependences of the resonant frequency and Q factor on liquids viscosity and mass density were theoretically investigated using a sphere-end oscillator model in viscous liquids and compared to experimental results. The theory and experimental results show that the piezoelectric-excited membrane can be used to measure liquids viscosity in a range from 19.88 cP to 1733 cP and mass density in a range from 0.829 g/cm³ to 0.886 g/cm³. Hence, the piezoelectric-excited membrane device is a promising candidate for rapid measurement of liquids viscosity and mass density, especially for wide-range viscosity measurement.