Transformation-governed heating technique in thermal analysis: Part III. Normalisation of experimental conditions

Abstract

The thermoanalytical research group at the Technical University Budapest elaborated already in 1962 a measuring technique called by them ‘quasi-isothermal, quasi-isobar thermogravimetry’ (Q-TG) operating with ‘transformation-governed heating control’ (TGHC). The course of curves taken by this technique reinterpreted the kinetics and mechanism of transformations and increased the resolution and selectivity of the method.

The authors extended this measuring technique also to the measurement of enthalpy change. They designed a heating control and measuring apparatus which can be used to all types of DTA, DDC, DSC or simultaneous DTA, TG, industrial instruments, even as an alternative solution. By means of these transformed equipments operating alternatively also with the non-isothermal programme, the ‘normal’ characteristic temperature of reactions or physical transformations could be measured. The ‘normalised’ course of curves, as well as the enthalpy change at ‘normal’ temperature could be determined. For this, only a simple transformation of the traditional heating control and the completion of software is necessary. Decomposition reactions of the type AB^s↔A^s+B^g can be investigated only in pure ‘self-generated’ atmosphere, i.e. in a labyrinth crucible.

The large scatter of the results published in literature — which are justly criticised by physico-chemists — can be totally eliminated by this measuring technique.