A two-dimensional information simultaneous measurement solution for surface roughness

Surface quality is one of the most important properties of an industrial product. The conventional techniques obtain the root mean square deviation σ, which represents the surface amplitude information. But it is not enough to precisely evaluate the surface quality. Peak number per inch PPI and correlation length T are introduced to identify surface frequency information. According to the theory of Beckmann´s light scattering, simplified mathematical models for surface roughness measurement are established. A whole measure solution is advanced and its reliability is verified by experiment. The new solution can realize to measure the amplitude and frequency information simultaneously, so the surface information is learned completely.