Description:
A weighed quantity of sample is placed in a crucible and heated to a high temperature for a fixed period. The crucible and the carbonaceous residue is cooled in a desiccator and weighed. The residue remaining is calculated as a percentage of the original sample and reported as conradson carbon residue. The carbon residue is a measure of the carbonaceous material left in a fuel after all the volatile components have been vaporized in the absence of air. It may be expressed as Conrad son Carbon Residue (CCR) or Micro Carbon Residue (MCR). Numerically, the CCR value is the same as that of MCR. No real correlation between the Conrad son carbon results for paralysis liquids and the deposit formation on injector nozzles has been reported. Fuels with up to 12 wt% CCR the significance of the Conrad son carbon test results also depends on the type of engine in which the fuel is to be used. Pressure jet and steam-atomizing-type burners are not very sensitive to the value of the carbon residue of the fuel to be used Conrad son carbon is normally only specified for light diesel fuels. The paralysis liquids are of a different chemical nature than mineral-oil-based heavy diesel fuels. There is not yet adequate information on diesel engine performance data for paralysis liquids, and this test was therefore also selected for evaluation.