Balance thermogravimetric analyzer

The heart of the thermogravimetric analyzer is the thermobalance, which is capable of measuring the sample mass as a function of temperature and time. The relationship between the components of a thermobalance varies from one instrument to another. A schematic representation as shown in Figs. 3.1a and 3.1b indicates typical thermocouple placements relative to the sample. The three standard sample and furnace positions relative to the balance are depicted in Fig. 3.1a. Figure 3.2 shows actual examples of currently available commercial instruments. 

In this section we briefly review commercial thermogravimetric analyzers in alphabetical order of manufacturer. Please visit the respective supplier Websites for current offerings and more information. See Section 3.2.1 for descriptions of balance configurations. While most suppliers offer autostep-wise software to control the furnace temperature (see Fig. 3.40), kinetics software such as the ASTM El 641 Flynn-Wall method described in Section 3.5.5, and the ability to interface to a Fourier transform infrared spectrometer (FTIR) or mass spectrometer (MS), the reader interested in these applications is advised to confirm the features of particular TGA systems. 

Experimental Section. The samples used in the TGA study were crushed to minus 200 mesh. Noniso thermal weight loss data were gathered using a DuPont 951 thermogravimetric balance with a DuPont 990 thermal analyzer. 

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