Abstract
Oil film thickness in rubber piston seals is measured by interferometry. Optimized optics and fluids enable clear interferograms. The oil film thickness on the contact area is measured during reciprocating motion. When the oil film formed on the contact area is sufficiently thick, monochromatic interferometry is applied to measure the variations in oil film profile. Under sealing condition, where the oil film is thin and even, the mean oil film thickness is measured by means of white light interferometry. The measurement results of oil film thickness correlate with the friction force.
