Development of Classical DTA to DSC

The thermocouple voltage due to AT is only 1 % or less than the voltage due to the absolute temperatures and must, thus, be preamplified before recording. Both AT (proportional to heat flow HF), and T, are then recorded either directly, as illustrated in Fig. A.9.1, or both are given as a function of time, t. Whenever the DTA trace can be used for the quantitative evaluation of caloric variables, such as heat capacities and heats of transition, the experiment is called DSC, differential scanning calorimetry. Many traditional DTAs are capable of measuring heat, and thus can be called DSC. 

In contrast, one finds many DSCs which are used only for qualitative DTA work on transition temperatures. The often-posed question of the difference between DTA and DSC is therefore easily answered DTA is the general term covering all differential thermal analysis techniques, while DSC must be reserved for scanning experiments that yield calorimetric information. 

Typical additional conditions for the design of early DTA instrumentation and its environment are  

Draft-free environment, closely regulated room temperature. 

High-thermal-conductivity furnace (silver, gold, or high-purity Al). 

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