Bl This standard establishes the procedure for the determination, in lubricating oils, of unsavory substances in precipitated naphtha and in benzene. Note: This procedure can also be used to determine the sulfated residue or lead, iron and carbon also when it is desired to obtain the portion insoluble in benzene.
IRAM 6618-1960 history
1960IRAM 6618-1960 How to determine the materials in lubricating oil that are insoluble in naphtha and benzene