A mathematical model for the conjugate formulation of the working conditions of the Q-derivatograph is created. There are no simplifying assumptions about the heat transfer processes for reacting active media and for their thermal interaction with the inert surroundings in this model. The energetic significance of the key components of the transfer and the redistribution of the fluxes is calculated by means of special balance relations. The influence of the kinetic and thermal reaction parameters on the nature of the establishment of the constant transformation rate is demonstrated. The accompanying heat phenomena are studied in detail. The essential differences in the behaviour of the TA system during endo and exothermal transformations are discovered. The exothermal reactions introduce significant irregularities, up to sharp oscillations.