Development of Identification Diagrams
In another important investigation technique applied in mineralogical sciences, the optics, a first introductory diagram exists which shows refractive index versus double refraction. With the aid of this diagram a mineral can be searched for, of which the optical characteristics are known by measurements. In differential thermal analysis it will be much more difficult than in optics to develop a similar introductory diagram. But on principle it is possible, if we take into consideration that DTA data are strongly influenced by a lot of apparative and preparative factors. If we do so and if we give some additional remarks, we will be able to construct an introductory diagram for DTA, too, using the temperature and ΔT as abscissa resp. ordinate to figure the characteristic data of a DTA peak. But we must not forget that both characteristics, the peak temperature as well as ΔT, can only be comparable with the data of other DTA runs if all runs have been made under comparable heating conditions. The following consequence is: such an introductory diagram temperature versus ΔT of a peak can be only valid for one set of investigation conditions. If you vary the heating rate, for example, you will get a shifting of the data. Therefore I propose to work under the standard conditions of analysis as listed in Table 1, and for these conditions the diagrams figured in the present study will be valid.
KeywordsDifferential Thermal Analysis Exothermic Peak Sheet Silicate Double Refraction Identification Diagram
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