The total acid number (TAN) is used as a quality control guideline when it comes to lubricating oil formations. Both used and unused petroleum may contain acidic components. The acid number test cannot be used to predict corrosive values of a lubricating oil under service conditions mainly because several oxidation products contribute to this number, and organic acids vary when dealing with corrosion.
Lubricating Oil Alkalinity Testing
The total base number (TBN) is a scale of the amount of basic substance within the oil. The TBN serves as a quality control indicator for lubricating oils as well. Alkalinity reserves can be identified by determining the total base number of an oil. Alkalinity is important for engine lubricating oils because it neutralizes the acids which form during combustion, which in turn protects the engine materials from corrosion. Lubricating oil tends to contain certain additives that can react with alkali to form metal soaps. PhosLube Petroleum Laboratories specializes in acidity and alkalinity testing for lubricating oils.