Abstract: An apparatus for non-contact measuring of surface roughness, comprises a source of light positioned for directing a light beam at a first angle onto a surface to be measured, a segmented multi-element array detector positioned to receive specular light reflected from the surface by an intermediate segment and to receive scattered light very close to the specular light by adjacent segments, the intermediate segment responsive to generate a signal in response to the specular light, and the adjacent segments each responsive to generate a signal in response to the scattered light, a second detector spaced from the first detector and at an angle less than that of the first angle, the second detector responsive to scattered light away from the specular light for generating a signal responsive to the scattered light, and a processor for receiving and processing the signals and displaying a reading corresponding to surface roughness.