As discussed in the initial overview of this series on MDSC (1), Modulated DSC
differs from standard DSC in that it applies two simultaneous heating rates to the sample.
The linear or average heating rate provides the same information (Total heat flow rate) as
standard DSC, while the sinusoidal (modulated) heating rate is used to determine the
fraction of the Total heat flow rate that responds to a changing heating rate. In general,
this heat flow rate is caused by heat capacity (Cp), changes in heat capacity, and by most
melting. This fraction of the Total heat flow is called the Reversing heat flow or the heat
capacity component of the Total heat flow. Heat flow that does not respond to the
changing heating rate is determined by subtracting the Reversing signal from the Total
signal. This difference signal is called the Nonreversing heat flow or the kinetic (timedependent)
component. Although DSC instruments measure the rate of heat flow, for the
purpose of simplicity "Heat Flow" will be used in place of "Heat Flow Rate" in the
remainder of this paper