1.1 This method covers the determination of acidic or basic constituents in petroleum products and lubricants (see1.2.1). The method resolves these constituents into groups having weak-acid, strong-acid, weak-base, and strong-base ionization properties, provided the dissociation constants of the more strongly acidic or basic compounds are at least 1 000 times that of the next weaker groups.
1.2 The method may be used to indicate relative changes that occur in an oil during use under oxidizing conditions regardless of the colour or other properties of the resulting oil. Although the titration is made under definite equilibrium conditions, the method is not intended to measure an absolute acidic or basic property which may be used to predict performance of an oil under service conditions. No general relationship between bearing corrosion and acid or base number is known.
1.2.1 In new and used oils, the constituents that may be considered to have acidic characteristics include organic and inorganic acids, esters, phenolic compounds, lactones, resins, salts of heavy metals, salts of ammonia and other weak bases, acid salts of polybasic acids, and additives, such as inhibitors and detergents. Similarly, constituents that may be considered to have basic properties include organic and inorganic bases, amino com-pounds, salts of weak acids ( soaps), basic salts of polyacidic bases, salts of heavy metals, and additives, such as inhibitors and detergents.
IS 1448 Pt.1-1971 history
1972IS 1448 Pt.1-1971 Neutralization number for potentiometric titration [P: 1]