TGA measures the change in weight of a sample as a function of temperature or time in a controlled atmosphere. This change in weight is usually accompanied by an evolution of gases caused by sample decomposition or volatilization. Identification of the components of the evolved gases helps determine sample characteristics that cannot be identified using TGA analysis alone.

TGA can be combined with Fourier transform infrared analysis (FT-IR) so that highly sensitive and specific infrared detection can accurately identify gases evolving from TGA measurements. Thermo Scientific offers such a system that provides real time monitoring of gases as they evolve from a heated sample.