The field at the end of the
probe in thematerial changed as it came into contact with thematerial
being tested. The reflected signal was then measured and related to the
dielectric permittivity parameters (dielectric constant ε′ and dielectric
loss factor ε″). Good contact between the probe and the sample was
made for all measurements to avoid erroneous values resulting from
the presence of air. For testing the dielectric properties of the drying
process, in order to make the same testing conditions for samples
with different water, the selected test points were 1 min after drying.
At least three replicates using different pieces were performed for
each sample.