AN-T-093
Total base number in engine oil with photometric titration
Summary
To prevent corrosion, engine oils are given additives to neutralize acidic compounds which are formed as a result of degradation processes. The total base number (TBN) indicates the amount of additives present and thus can be used to estimate the degradation of the engine oil.
Using an automated titration system with a photometric sensor to detect the endpoint ensures consistent conditions for the titrations. This improves the precision and reliability of the results. This Application Note describes the fully automated photometric determination of TBN in used engine oil with the Metrohm Optrode to indicate the methyl orange endpoint (at 520 nm).