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

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 Dektak 3 ST® and a Hommel T 1000, and a Dimension 3000® atomic force microscope (AFM). Arithmetic roughness ( R a ), root mean square roughness ( R q ), and mean peak‐to‐valley height ( R ZD ) were statistically analyzed. Each instrument yielded reliable results, but there were significant differences between the AFM and the other two instruments. The ability of R ZD 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.