ISO Standardized Form Removal and Filtering of Surface Texture for Areal Surface Roughness Measurement Using Zygo Mx

Abstract

The areal quantitative analysis of the surface texture is performed using non-contact type 3-D optical surface profilometer. The captured curved surface consists of macroscopic form, waviness, roughness, and system noise correspond to large, intermediate, small, and very small wavelength signal respectively. It is important to separate the roughness from the captured surface to measure the surface roughness of a component correctly and accurately. This paper presents a method to remove the form and filtering process of surface texture for areal surface roughness measurement according to ISO 25178-2:2021. The S-filter is used to remove the system noise with suitable nesting index resulting in primary surface. The F-operator is applied to the primary surface to remove the form error by fitting the suitable polynomial which results in the S-F surface. Further, The L-filter is applied to the S-F surface to get the areal roughness surface. Additionally, these processes are explained using Zygo Mx software by considering some surface geometries such as spherical, cylindrical, and freeform.