The total base number (TBN) provides important information about the remaining amount of additives present in motor oil. Together with other parameters, TBN can be used to estimate the remaining lifetime of an oil. Thermometric titration is ideal for analyzing TBN in motor oils – especially used motor oils – as the titration is not affected by colored samples and the sensor does not require any conditioning or extra cleaning steps.
The total base number is determined by titrating the motor oil sample with a standard solution of trifluoromethanesulfonic acid in glacial acetic acid. Isobutyl vinyl ether is used as a reagent for better endpoint detection.