Section 1.2 of Method D189-06(2014) specifies that SI units are to be regarded as standard and that no other units of measurement are included in the standard. Section 8.1 directs that the sample be filtered through a 100-mesh screen. However, mesh is not an official SI unit. Despite extensive research no rationale was found for the addition of the filter step. The precision statement was written when no filtration step was included in the method, so to make the precision statement agree with the method it should be removed.
KeywordsConradson carbon residue; lubricants; petroleum products;;
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