Applicability of acoustic plate modes with quasi-longitudinal polarization to liquid parameterization

Abstract

A class of acoustic waves suitable for liquid parameterization is demonstrated not to be restricted to acoustic modes with shear-horizontal polarization. Its substantial extension can be achieved by adding widespread plate modes with quasi-longitudinal (QL) polarization. Their investigation is performed by an example of 128°-rotated Y-cut LiNbO3 plates. The sensitivity of plate modes to the conductivity of liquid adjacent to one of the plate surfaces has been found to depend on a mode number, a plate thickness, and electric conditions on the opposite surface. It is demonstrated that their sensitivity to temperature is affected by the liquid viscosity. One of the QL modes existing in the 128°Y, X + 90° -LiNbO3 plate has been determined numerically. Its applicability for monitoring the electric characteristics of low-viscous liquid media has been examined experimentally.