The earlier chapters have described the principles and uses of conventional differential scanning calorimetry (DSC), whereby a linear heating signal is applied to a sample, and the temperature and energy associated with the response are measured. Along with differential thermal analysis (DTA), this method remained the industry standard for approximately 30 years, until the introduction of modulated temperature DSC (MTDSC) in the early 1990s (1-4). The innovation associated with this technique lies in a software modification so as to allow the superimposition of a modulation on the underlying signal, described in more detail in the following text.