This standard specifies the determination of base number in test specimen by potentiometric titration with perchloric acid.
The method specified in this standard includes forward titration and back titration, and Procedure A and B are used in each kind of titration.
Note: as for additives, new and used oils, the test shows that the two procedures give statistically equivalent results. The test shall be judged according to Procedure A.
This standard is applicable to determining the basic constituents in petroleum products, used oils and additives. These constituents include organic and inorganic bases, amino compounds, salts of weak acids (soaps), basic salts of polybasic acids and salts of heavy metals.