A review has been given on the development and problems of thermal analysis with emphasis on the pioneering works in Japan and theoretical aspects. Japanese scientists have played an important part in the development of thermal analysis, which includes improvements of the sample holder and thermocouple system in differential thermal analysis (DTA), and original ideas and approaches in thermogravimetry (TG) and evolved gas analysis (EGA). In differential scanning calorimetry (DSC), the actual

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... ple temperature is different from the recorded temperature because the temperature measurement is made outside the sample. The temperature-lag of the sample can be theoretically evaluated for the first-order phase transition. A principle of the base line drawing is given for determining the enthalpy of the first-order phase transition in which the heat capacity of the sample is different before and after the transition. The enthalpy of the transition is obtained from the area enclosed by the base line thus drawn and the recorded peak. In TG technique, the temperature-lag is also significant if the sample temperature is measured by a thermocouple located outside the sample container in the furnace. The temperature reading has been proposed to be calibrated against a thermocouple positioned at the same place of the sample container in the furnace. The EGA is a powerful tool in the study of complex solid-gas reactions, especially as a simultaneous technique coupled with TG.