  The Piezo-electric Shear Gauge (PSG) [Christensen & Olsen, Rev. Sci. Instrum.
66, 5019, 1995] is a rheometric technique developed to measure the complex
shear modulus of viscous liquids near their glass transition temperature. We
report recent advances to the PSG technique: 1) The data extraction procedure
is optimized which extends the upper limit of the frequency range of the method
to between 50 and 70 kHz. 2) The measuring cell is simplified to use only one
piezo-electric ceramic disc instead of three. We present an implementation of
this design intended for liquid samples. Data obtained with this design
revealed that a soft extra spacer is necessary to allow for thermal contraction
of the sample in the axial direction. Model calculations show that flow in the
radial direction is hindered by the confined geometry of the cell when the
liquid becomes viscous upon cooling. The method is especially well-suited for
-- but not limited to -- glassy materials.
