Thermogravimetric analysis is a method of measuring the weight of a sample during the heating processThis process can be carried out under various blowing gases that control the material degradation mechanism. Most polymer research uses nitrogen or other inert gases (such as helium or xenon) as purge gases to ensure that the polymer undergoes pyrolysis rather than combustion. In the later stage, the blowing gas can be switched to air or oxygen, which allows for the quantification of carbon from carbon black or carbon coke produced by polymer pyrolysis by measuring the weight lost due to the formation of carbon dioxide from carbon combustion. The remaining samples after this step are considered as inorganic fillers or "ashes".