Method description:
The individual molecules present in the oil absorb typical infrared light. Based on the difference between the ‘blank’ and the beam after passing through the oil, an inferogram is produced which, when subjected to a mathematical Fourier transform, gives the IR spectrum – the dependence of absorbance on wave number.
Interpretation of results:
By comparing the spectrum of a reference oil with that of an in-service oil sample, it is possible to determine e.g.: water content, phenolic inhibitor content, oxidation, nitration, sulphation, soot content, glycol, fuel, compatibility with a reference sample or differentiation of the oil base.