We show in this work that the heat flow signal as acquired applying DSC to systems in an excess of epoxy must be proportional to the rate of consumption of the excess component but not to the rate of reaction. The rate equations reasoning from this finding have been analysed. According to the model, a DSC data set monitoring the reaction progress of an epoxy excess system must be identical to that exhibiting the reaction advance of the formulation at stoichiometry. Experimental data confirming the proposed methodology have been presented. Both non-isothermal and isothermal DSC experiments support adequately the model. The non-linear transform from the excess component measurement into the reaction rate expression has been also commented in the Study from the point of view of the kinetics. (C) 2008 Elsevier B.V. All rights reserved.