C H A P T E R 1
INTRODUCTION
1.1 Heat, Temperature, and Thermal Analysis
The most fitting introductory discussion on thermal analysis is perhaps a brief outline of the history and meaning of the two basic quantities: heat and
temperature. In Fig. 1.1 some facts about heat are summarized. Heat is quite obviously a macroscopic quantity. One can appreciate it with one's senses directly. The microscopic origin of heat, the origin on a molecular scale, is the motion of the molecules of matter. The translation, rotation, and vibration of molecules thus cause the sensation of heat, and one can summarize: the macroscopically observed heat has its microscopic origin in molecular motion. Temperature, in turn, is more difficult to comprehend. It is the intensive parameter of heat, as is shown in Sect. 2.2.1. Before we can arrive at this conclusion, many aspects of temperature must be considered.