ROUGHNESS MEASUREMENT OF MACHINED SURFACES BY MEANS OF THE SPECKLE TECHNIQUE IN THE VISIBLE AND INFRARED REGIONS

Measurement of surface roughness by means of speckle technique has the advantage of being noncontacting and applicable to an in-process envi ronment. Results from measurements of speckle contrast on ground surfa ces are shown. The measurement range in the configuration used is R(q) less-than-or-equal-to 200 nm. Comparisons of results between calculat ed and experimentally achieved speckle contrast are in agreement. An e mpirical method is presented that can be used to classify machined sur faces according to roughness when no specular component exists in the scattered light. The measurement range of this method is highly depend ent on the machining process used. Surfaces with R(a) less-than-or-equ al-to 3.2 mum are classified according to roughness.