1.1.1 Test Method A—For petroleum products and lubricants soluble or nearly soluble in mixtures of toluene and propan-2-ol.
It is applicable for the determination of acids whose dissociation constants in water are larger than 10-9; extremely
weak acids whose dissociation constants are smaller than 10-9 do not interfere. Salts react if their hydrolysis constants are larger than 10-9.
The range of acid numbers included in the precision statement is 0.1 mg/g KOH to 150 mg/g KOH.