Characterisation of lubricants on ball bearings by FT-IR using an integrating sphere

Fourier transform‐infrared reflectance microspectroscopy has been used extensively for the examination of coatings on non‐planar surfaces such as ball bearings. While this technique offers considerable advantages, practical application has many drawbacks, some of which are easily overcome by the use of integrating sphere technology. This paper described the use of an integrating sphere for the quantification of thin layers of lubricant on the surface of ball bearings and the parameters that require optimisation in order to obtain reliable data. Several applications of the technique were discussed including determination of lubricant load on 12.7mm steel ball bearings and the examination of degraded lubricant on post‐mortem specimens. Copyright © 2007 John Wiley & Sons, Ltd.