Evaluation of Smooth Surface Roughness of Nonmetallics by Micro Interference Method

To estimate a roughness of the surfaces characterized by Ra ? 0,01 ?m is possible by measuring system ?Micron-alpha? on the basis of the optical device MII-4. The device for digital fixing of the MII-4 scans a surface area in the size no more 250×190 ?m. However in this case from regulated by standard ISO of size of sampling length (0,08 mm) and a parity of sampling length and evaluation length (0,08/0,4) the second is not carried out. The article shows that values of surface roughness parameters of such materials as sapphire and zirconium dioxide ceramics calculated by the mentioned measuring system are comparable to results of an evaluation of the roughness, worked out at scanning of surface area of 10 times bigger size. At the same time more high sensitivity of such estimating technique to local defects of a surface such as appearance of a pores on a surface, small chips or scratches, requires to use in measuring not less than 10 evaluation tracks.