This International Standard specifies a method for the determination of the amount of carbon residue, in the range 0,lO % (m/m) to 30,O % (m/m), left after evaporation and pyrolysis of Petroleum products under specified conditions. For products which yield a residue in excess of 0,lO % (m/m), the test results are equivalent to those obtained by the Conradson carbon residue test (see ISO 6615). This International Standard is also applicable to petroleum products which consist essentially of distillate material, and which may yield a carbon residue below 0,lO % (m/m). On such materials, a 10 % (WV) distillation residue is prepared by the procedure described in ISO 3405 before analysis. Both ash-forming constituents, as defined by ISO 6245, and non-volatile additives present in the Sample add to the carbon residue value and are included in the total value reported. NOTES 1 The carbon residue value serves as an approximation of the tendency of Petroleum products to form carbonaceous deposits under similar degradation conditions, and tan be useful in the assessment of relative carbon-forming tendencies of products within the same class. Care should be taken in the interpretation of results. 2 The presence of organic nitrates incorporated in certain distillate fuels will yield abnormally high values for the carbon residue. The presence of alkyl nitrate in the fuel may be detected by ASTM Test Method D 4046.