Derivation of a general formula and a general area method for latent heat via differential thermal analysis

In this paper, a generalized expression for latent heat has been derived by considering temperature gradients within the sample, and the usual situati on in which the specific heat of the sample changes during the transition a nd specific heats in both low- and high-temperature states are functions of the temperature. For a reversible transition, when the specific heat of a sample is a slowly changing function of the temperature, the errors caused by the temperature gradient within the sample can theoretically be minimize d by averaging the latent heats obtained from both the heating and cooling process. It is also pointed out that the latent heat is proportional to the area enclosed by peak curve and the imaginary equivalent non-latent heat b aseline. (C) 1998 Elsevier Science B.V. All rights reserved.