Non-isothermal mode. Prediction of the reaction progress (-) and reaction rate d/dt (s-1) for chosen heating rates (°C/min) and selected starting temperatures.

Example 1
TG, MS, reaction progress :
Comparison between TG, MS-H₂O (Gas 1) and MS-CO₂ (Gas 2) (expressed as reaction progress , normalized signals) of an inorganic pigment under non-isothermal conditions (10 °C/min).

Example 2
DTG, reaction rate d/dt

Comments:

In general, non-isothermal scans with different heating rates are carried out within a much wider temperature range than is possible, from the experimental point of view, in isothermal conditions. This allows discernment between the different reaction paths involved in the kinetic process because the data contain the necessary information on the time-temperature dependence of particular processes which is a prerequisite for the correct identification of the complex nature of the investigated reaction.

Computations are usually made with the results obtained from at least 5 heating rates. The application of heating rates too close to each other should be avoided. If they are very close, they become tantamount to a model-fitting analysis using single heating-rate methods. Consequently, they may fail the required purpose as amply reported in the literature [cf. 1, 2].

[1] M. Maciejewski, Thermochim. Acta, 355 (2000) 145.
[2] M. Criado, A. Ortega, F. Gotor, Thermochim. Acta, 157 (1990) 171.