Automated surface roughness assessment

A fiber optic sensor system is described for non-contact measurement of surface texture. The sensor employs a fiber optic guide and lens arrangement that forms an interferometric cavity between the lens front face and the surface. Changes in the surface topography are manifested as phase changes between the light reflected from the surface and the front face of the lens. An electronic control and data acquisition system converts the phase change into a voltage signal proportional to surface topography. The sensor performance is evaluated against stylus profoliometer results and comparison of the amplitude parameter, R-a, shows good agreement.