Differential Thermal Analysis:

In the earlier Unit we discussed thermagravimetric analysis and its applications. You have learnt which TGA has several applications, other than they are limited to the reactions whereas mass change should have occurred. Presently we will consider two same thermal techniques, differential thermal analysis (DTA) and differential scanning calorimetry, both these methods have much wider applications than TGA. Within the last section of this unit, thermometric titrations and their applications have been briefly discussed.

As defined previous, in DTA, the heat changes inside a material are monitored through measuring the difference in temperature (?T) among the sample and the inert reference. This differential temperature is then plotted against temperature or time to get DTA curve. Within differential scanning calorimetry (DSC), the initial temperatures of the sample and the reference are kept similar. The amount of heat which has to be supplied to the sample or reference to achive this equivalence in temperature is continually measured over the temperature range employed. This basically measures of the amount of energy absorbed or evolved within a particular transition, and hence provides calorimetric measurements directly. Same to DTA Curve, DSC Curve could be acquire through plotting differential heat input to the sample (expressed as a heating rate dH/dt) against temperature and time (t). With this background, now we will assume the instrumentation and applications of DTA method.