A novel application of white light sensing to dynamic oil film measurement

Monitoring of the thickness of dynamic oil films is of great interest to engine manufacturers and oil producing companies. The technique described in this paper uses white light interferometery incorporating the channelled spectrum technique, which exhibits an accuracy of ~0.1 μm and allows absolute distance measurements to be made over approximately 5 mm working range. In order to overcome the zero offset characteristic of white light interferometers, a novel probe design is described that utilises a titanium dioxide coating to improve the reflectance of the fibre end-face. Application to a simulated IC engine connecting rod test rig is performed and the resultant distribution of oil film thickness for given speeds of a rotating shaft are shown