A comparison of surface roughness of pipes as measured by two profilometers and atomic force microscopy

Abstract

The objective of this study was to develop a reliable method for the measurement of pipe surface roughness. Roughness of coated pipe was measured with two linear surface profilers, a Dektak3ST® and a Hommel T 1000, and a Dimension 3000® atomic force microscope (AFM). Arithmetic roughness (Ra), root mean square roughness (Rq), and mean peak-to-valley height (RZD) were statistically analyzed. Each instrument yielded reliable results, but there were significant differences between the AFM and the other two instruments. The ability of RZD to ignore intermediate height data while focusing on extreme height data made it a useful parameter for detecting differences in height that would be the most likely to affect fluid flow in pipes.