A method to evaluate the temperature dependence of the reaction rate from the variation of the amount reacted at the end of a number of experiments at various scan rates is deduced from the fundamental equations of DTA, The method was applied to the synthesis of Paakkonenite and gave parameters in good agreement with those determined for the same reaction by using other experimental data and the differential method of Sharp and Wentworth. Furthermore, an empirical procedure previously used to get the same results is compared with the present elaboration. The parameters evaluated are reported and discussed.