In this work, a non-contact approach using interference fringes is used for characterizing the surface roughness of diamond polished stainless steel specimens. The interference fringes formed over the surfaces due to the interference of coherent beams can give important details about the surface topography of the material. A fringe intensity curve based parameter developed by plotting the fringe intensity curves at different heights was observed to have a linear relationship with stylus roughness. The value of coefficient of correlation obtained was is 0.71. The average standard deviation of the interference fringe intensity curves were observed to bear a linear relation with the measured stylus roughness with a correlation coefficient of 0.84.The non-contact optical methods used in this work for charactering the surface roughness are cost effective and has an advantage of non contact roughness characterization.

Keywords: Surface roughness, Intensity fringe curve, image processing, machine vision, standard deviation, roughness parameter