A characterization of surface roughness
Abdul Rahim, Abdallah Adel
Merwin, John E.
Master of Science
A study is made on the surface finish of five ground specimens in an attempt to improve on their surface roughness characterization. Surface finish is characterized by a single statistic referred to in practice as the Center Line Average height value (CLA). This CLA height value is a measure of the roughness contribution to surface texture. A fourth order, low pass Butterworth filter is used to separate the contribution of roughness, waviness and error of form that are present in the surface texture. Applying this filtering technique eliminates the need of varying meter cutoff lengths to maximize and minimize those contributions. A statistical analysis provided a choice of ranges of cutoff periods where the CLA height values appear to be more representative of the roughness characteristics of the surface texture. Additional studies using other surfaces are necessary to improve on the single number characterization of surface roughness.