Extraction of shape and roughness using scattering light

Abstract

The extraction of 3D shape and roughness by optical measurement techniques become more and more import in industrial applications. Optical systems are measuring fast with high accuracy and give reliable information about the workpiece form or surface roughness. The classical systems based on triangulation, white light, confocal, shadow or fringe projection techniques and are applied with a great success in recent years. In future there will be a growing interest in robust inline measurement techniques to monitor the manufacturing process. E. g. some automotive manufactures are using confocal systems to characterize the surface of cylinder liners inline. But there is another robust and powerful technique suitable for inline measurement purposes: scattered light sensors. In this paper, a special type of a scattered light sensor based on the former Rodenstock RM 400 sensor is considered. The sensor enables the user to measure form and roughness in a robust manner. The properties of the sensor are analyzed system-theoretically.