Carbon Residue (Conradson / Ramsbottom)

Definition

Carbon Residue (Conradson / Ramsbottom) is the percent of coked material remaining after a sample of lubricating oil has been exposed to high temperatures under ASTM D189 (Conradson) or ASTM D 524 (Ramsbottom). Results are reported as a percentage of the weight of the original sample. As far as the affect of residue on performance, one opinion is that the type of carbon is of greater importance than the quantity. Since compounded oils contain metallic additives that generally leave a residue, other testing should be done to also identify the type of residue rather than just the amount.

Standard Test Method Used

Conradson - ASTM D189 / IP13
Ramsbottom - ASTM D524

Reporting Measurement

%

Amount of Sample Needed

200 mL