Development of a Behaviour Curve for Quality Evaluation with Optoelectronic Profilometers Eduardo Cuesta 1,a* , Daniel Gonzalez-Madruga 2,b , Braulio J. Alvarez 1,c and Marta García-Dieguez 1,d 1 Dept. of Manufacturing Engineering, Campus de Gijon, Gijon, University of Oviedo, Spain 2 Dept. of Mechanical & Aerospace Engineering, Campus de Vegazana, University of Leon, Spain a ecuesta@uniovi.es, b danimadru@gmail.com, c braulio@uniovi.es, d garciadmarta@uniovi.es Keywords: Optoelectronic profilometer, Surface quality evaluation, Roughness measurements. Abstract. This work shows an experimental procedure aimed to generate a graph with the optimal roughness parameters in order to obtain the best roughness measurements of an optoelectronic profilometer. The optimal parameters have been determined taking into account the grade of agreement between the optical roughness values and the equivalent values of traditional contact devices. The working parameters of the optoelectronic profilometer are based on computational filters which are controlled by software working with a 3D stratified colour map (chromatic fragmentation of the white light). However, these parameters substantially differ from the usual contact profilometers that work with 2D roughness profiles (cut-off, evaluation length and contact stylus radii). This work pursues to find the optical profilometer parameters, and its values, that ensure the best quality measurement for a wide range of machining process and testing several ISO roughness intervals. Introduction Optoelectronic profilometers employing white light have considerable potential and measuring capabilities, allowing to create real 3D surface maps of a relatively large areas. Depending on the lens (probes) used on the profilometer, an area up to a few squared centimeters can be processed with a sub-micrometric scale. Thanks to these maps, surface quality parameters such us amplitude, spacing and hybrid parameters on the roughness and waviness profiles can be measured without any contact with the part. In addition this technology allows for an elevated data acquiring speed, around thousand points per second, what enable a significant reduction in the operation time and consequently in the cost of the inspection task. In spite of the above advantages, there are still some drawbacks that need to be overcome in order to face up to the conventional methods for roughness measurement. Apart from differences in price and other commercial trades, comparison between technologies was previously studied for specific metallic materials [1,2,3] and non-metallic surfaces [4] but a deeper comparison for covering the most common machining processes is needed [5], especially when a wide range of machining processes are considered. There are many parameters that have influence on the measurement; apart from the parameters related with the sensor, other optical parameters must be considered such as the light wavelength, interference phenomena, diffraction, reflection, surface optic characteristics, orientation and machining patterns, colour or brightness, similar to what happens with other optic inspection processes like laser triangulation sensors [6]. The objective of this work is to analyse the conformity of the roughness parameters measured with an optoelectronic profilometer in order to make the measurement results equivalent with those obtained with traditional contact devices. The working parameters of the optoelectronic profilometer are controlled by software and based on filters which are modified depending on the measurement basis, chromatic fragmentation of the white light in this case. However, these parameters substantially differ from the usual contact profilometers (cut-off, evaluation length, Key Engineering Materials Vol. 615 (2014) pp 51-56 Online available since 2014/Jun/30 at www.scientific.net © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/KEM.615.51 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 93.156.84.251-03/07/14,22:01:51)