scope:

This Standard specifies a method for determining the amount of carbon residue, in the range of 0.01 % to 30.0 % mass fraction, left after evaporation and pyrolysis of crude petroleum and petroleum products, according to Conradson method. This Standard is also applicable to 10 % residual oil of light oil, heavy oil A and petroleum products similar to these.

NOTE 1 The carbon residue of oils may give an indication of the propensity of the oil to lay down deposits in combustion chambers in diesel engines. The presence of alkyl nitrates (cetane improver) in petroleum products, though it does not affect the amount of carbide produced in combustion chamber, will give carbon residue results that are higher than the corresponding values on the fuel without additives. Therefore, in the case of such products, for the relation of the produced carbide amount in combustion chambers and carbon residue, the value of carbon residue shall exclude the increase attributed to the addition of alkyl nitrate. The method of determining alkyl nitrates is specified in ISO 13759.

NOTE 2 Carbon residue includes ash-forming components and non-volatile additives.

NOTE 3 The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows:

ISO 10370 : 1993 Petroleum products-Determinution of carbon residue- Micro method (MOD)

The symbols which denote the degree of correspondence in the contents between JIS and the corresponding International Standard are IDT (identical), MOD (modified) and NEQ (not equivalent) according to ISO/IEC Guide 21.