The dependence of film thickness on Hertz pressure at pressure levels typical of design applications has been investigated. The data presented by investigators at NASA and Battelle using an X-ray transmission technique showing a dependence much greater than that indicated by commonly accepted theories are substantiated by an independent study using an optical interference film thickness measurement technique. It is also shown that the minimum film thickness is influenced to a much greater extent by the Hertz pressure than the center line film thickness.
Lee DD, Sanborn DM, Winer WO. Some Observations of the Relationship Between Film Thickness and Load in High Hertz Pressure Sliding Elastohydrodynamic Contacts. ASME. J. of Lubrication Tech. 1973;95(3):386-390. doi:10.1115/1.3451838.