This test method covers the determination of the amount of carbon residue (Note 1) left after evaporation and pyrolysis of an oil, and is intended to provide some indication of relative coke-forming propensity. This test method is generally applicable to relatively nonvolatile petroleum products which partially decompose on distillation at atmospheric pressure. Petroleum products containing ash-forming contituents as determined by Test Method D 482, will have an erroneously high carbon residue, depending upon the amount of ash formed (Note 2 and Note 3)
