METHOD FOR CONTACTLESS DETECTION OF SURFACE ROUGHNESS PARAMETRES AND DEVICE FOR ITS REALISATION Russian patent published in 2009 - IPC G01B11/30 G01B21/30 

FIELD: physics, measurement.

SUBSTANCE: invention may be used for contactless detection of quality in items having medium and low classes of purity. Detection of surface roughness parametres is carried out by digital survey of investigated surface or its area by digital optical device with resolution of at least 3 megapixels at angle of illumination of 15°, 45°, 75° with normal location of lens to investigated surface. Digital pictures are sent to computer, pictures are processed and analysed on the basis of calculation of statistical criteria of each picture. Mean-square deviation is found between statistical criteria, which is correlated with arithmetical mean deviation of roughness sample Ra. Restoration coefficient k is determined. Electronic model of surface microrelief is built by transformation of picture pixels into three-dimensional coordinates, which are used for calculation of geometric parametres of surface roughness.

EFFECT: higher efficiency of surface roughness parametres measurement.

2 cl, 14 dwg, 8 tbl