A comparative study of methods for treating the end effects in surface finish measurement

Surfaces in engineering can be considered as a weighted overlapping of various sinusoidal components which can be separated by their wavelength. The study of the influence of surface micro-geometry on the functional behavior of the pieces requires the separation of these components. This separation is carried out by applying filtering techniques to the digitized values representing the considered profile or surface. Most widespread filtering techniques, such as the Gaussian filtering, are based on a convolution between the points of the surface with a weighting function. While convolution is being performed, those points near to the ends of the sample length have not enough information to rightly perform the convolution and the phenomenon known as end effect appears consequently. The present work makes a comparative analysis between different criteria proposed by the ISO standards to reduce the impact caused by the appearance of the end effects.