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DIFFERENTIAL SCANNING CALORIMETRY, INTRODUCTION AND
PRINCIPLE
WHY DSC?
Both the thermal techniques which have been discussed so far, TGA and
DTA, are mostly used for qualitative and semi-quantitative analysis.
Information like identification of various substances, phase
transformations, thermal stabilities and study of exothermic and
endothermic reactions can be readily obtained by these techniques.
But in both the cases, as the changes are measured as a function of
temperature, which is not a sensitive parameter to be accurately
measured, hence in analytical terms only semi quantitative data can be
obtained. Better quantitative data can be obtained by using differential
scanning calorimetry (DSC).
PRINCIPLE: Differential Scanning Calorimetry (DSC) is not much
different technique than DTA. In DSC also the sample is heated along
with a reference material through a programmed temperature range.
However, in the case of a change in the sample, the temperature
difference between the sample and the reference can be compensated
by providing extra thermal energy either to the sample or to reference.
This additional energy, usually in form of electric current, which is
provided to keep the sample and the reference at equal temperatures is
