| Summary: | An experimental apparatus and data acquisition system was constructed
to measure the streaming potential coupling coefficients as
a function of frequency. The purpose of the experiments was to measure,
for the first time, the real and imaginary portion of streaming
potentials. In addition, the measured frequency range was extended
beyond any previous measurements. Frequency-dependent streaming
potential experiments were conducted on one glass capillary
and two porous glass filters. The sample pore diameters ranged
from 1 mm to 34 ¹m. Two frequency-dependent models (Packard
and Pride) were compared to the data. Both Pride’s and Packard’s
models have a good fit to the experimental data in the low- and
intermediate-frequency regime. In the high-frequency regime, the
data fit the theory after being corrected for capacitance effects of
the experimental setup. Pride’s generalized model appears to have
the ability to more accurately estimate pore sizes in the porous
medium samples. Packard’s model has one unknown model parameter
while Pride’s model has four unknown model parameters, two
of which can be independently determined experimentally. Pride’s
additional parameters may allow for a determination of permeability.
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