Optical control of surface finish

Measurement of surface roughness on mechanical components, which may incorp orate also critical profiles, using diffused light techniques is a very com plex problem. This paper describes a new optoelectronic device employing a diode laser and an array of discrete photodetectors placed on an arc of cir cle and interfaced with a data acquisition board. The device allows an exte nded range of roughness measurements; it is compact, easy to be used and al most insensitive to external noise and vibrations. It provides an estimatio n of the surface quality parameters comparing the scattered light at two di fferent ranges of angles thereby overcoming many of the earlier limitations . The experiment has evidenced that there is a good agreement between measu rement results and theoretical model usually applicable to normally distrib uted surfaces. (C) 2000 Elsevier Science Ltd. All rights reserved.