ISO 4262
RAMSBOTTOM CARBON RESIDUES OF PETROLEUM PRODUCTS.
This International Standard specifies a method for determining the amount of carbon residue, in the range of 0,01 % (m/m) to 30,0 % (m/m), left after evaporation and pyrolysis of an oil, and is intended to provide some indication of relative coke-forming tendency. The method is generally applicable to relatively non-volatile petroleum products which partially decompose on distillation at atmospheric pressure.