A technique in which the mass of a substance (and/or its reaction product(s)) is measured as a function of temperature whilst the substance is subjected to a controlled temperature program.
Sources:
Orange Book, 2nd ed., p. 39 (https://media.iupac.org/publications/analytical_compendium/)
PAC, 1985, 57, 1737. 'Nomenclature for thermal analysis - IV (Recommendations 1985)' on page 1738 (https://doi.org/10.1351/pac198557111737)