CALORIMETRIC EQUIPMENT WITH TIME-EVOLUTION PARAMETERS MEASUREMENTS AND MODELING IN FLOW AND MASS-VARYING CALORIMETRY

The injection calorimeters are used to evaluate thermodynamic properti es of the mixtures and solutions. The H(i)E partial molar excess entha lpies or the L(phi), i relative apparent molar enthalpies against mole fraction are, available from an appropriate signal processing of the calorimetric curves. An evolution of the thermal properties of the cal orimetric vessel are associated with the injection process. Descriptio n of calorimetric equipments by means of a localized - constants model (RC analogy) allows us to systematize and to extent these systems int o time dependent situations. Experimental measurements based on Joule effects and associated mathematical analysis permits to determine the absolute limits of the dynamic behaviour of these equipments from seve ral standard and easily experimental parameters (sensitivity, noise le vel, tau(l) the first time constant, sampling period). Models and expe rimental study provide an estimation of the corrections in order to co mpensate the evolution of the physical characteristics of the device.