DIN 51551-1
DIN 51551-1 Testing of lubricants and liquid fuels - Determination of the carbon residue - Part 1: Conradson method
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/2009
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/2009