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The characteristics of shear horizontal (SH) wave propagation on a piezoelectric ceramic plate having the poling axis along the horizontal direction are described. The zeroth-order symmetrical (S0) mode has a nearly nondispersive property and an interdigital transducer (IDT) for the S0mode under the configuration of no counter electrode on the opposite surface of the plate has a high electromechanical coupling constant k2value exceeding 20% throughout the entire range of frequency times thickness (fd) values. The viscosity of a ferroelectric liquid crystal (FLC) is measured using the S0mode SH wave device which has two acoustic wave channels. In the smectic phase of FLC, the viscosity in the direction perpendicular to the smectic layer plane is larger than that parallel to it. The difference in the viscosity between the two directions of FLC alignment is detected by measuring the acoustical phase delay difference between two acoustic wave channels.