Basic additives are added to petroleum products to inhibit corrosion as they have a neutralizing effect on acidic compounds, which are formed as a result of degradation processes. Total base number (TBN) indicates the amount of basic additives present and thus can be used as a measure for the degradation of the petroleum product.
Using an automated titration system with a photometric sensor to detect the end point ensures that the titrations are always carried out under the same conditions. This improves the precision and reliability of the results.
This Application Notes describes the fully automated photometric determination of TBN in used engine oil using the Metrohm Optrode for the indication of the methyl orange endpoint (at 520 nm).