This International Standard specifies the method for continuous (single post-exposure mass measurement on each of a series of specimens without intermediate cooling) and discontinuous (series of mass measurements on a single specimen with intermediate cooling at predetermined times not necessarily regular, and relatively few in number) isothermal-exposure testing under high-temperature corrosion conditions of metallic materials in gaseous environments. In contrast, thermal-cycling oxidation testing (series of mass measurements on a single specimen with frequent regular cooling in order to accelerate high-temperature corrosion) is not included in this International Standard.