COMPARISON BETWEEN TALYSURF 10 AND OPTICAL MEASUREMENTS OF ROUGHNESS AND SURFACE SLOPE

Talysurf 10 and specular and diffuse light reflection results are compared for a set of ground metal surfaces. The specular reflection results correlate well with Talysurf roughness values. The intensity-incidence variation can be regarded as the characteristic function of skewed roughness probability distributions of a type suggested by earlier work. One apparently anomalous result helps to show the usefulness of the optical methods. Adequate representation of the diffuse reflection results is achieved by a double sech function with two angular dispersion parameters. The Beckmann theory is applied to derive the autocorrelation function of the slopes which shows a correlation length of around 0.15 μm. This small value may explain the fact that the scattered light is dispersed through angles much greater than the mean slope indicated by the Talysurf. The inner dispersion parameter of the double sech function is closer to the Talysurf values but the significance of this is not clear. © 1979.