While DSC measures heat flow of a sample, TMA measures the
compressibility. Below the T
g, the material behaves as a solid and
displacement ofthe plunger is minimal. As the sample heats up it
begins to flow and fills the voids between the particles stacked in
thecompressioncup.Theorydictates thatvolumechangeis closely
related to T
g and as the cup walls are of a fixed circumference, it
is important to note that the displacement measured by the TMA
instrument is directly proportional to the volume change in the
sample.Thus,inthis instance,T
g is theoreticallyrelatedtodisplacement of the plunger as well as the volume change in the sample.