The relation between reflected light intensity and surface roughness parameters was analysed by numerical calculations based on BECKMANN'S theory. In addition, detailed analysis was made in case that the statistical characteristic of surface topography deviated from the one assumed in the theory.
From these considerations, the conditions appropriate for surface roughness measurement were selected in terms of the incident angle and wavelength of a light beam. The experiments under these conditions gave good results for different kinds of steel sheets.
These results lead to the development and installment of an on-line roughness measurement system in a TPL, (temper and processing line) of Chiba Works.
