Figure 1
Effect of pixel number of AFM images on the measured roughness. A) AFM height images of a control specimen (untreated composite surface) for which the same region has been imaged (scan size S = 30 μm) with increasing number of pixels, N = 322, 642, and 1282 from left to right. Height range is 900 nm for all images. Images not shown here completed the sequence, with N = 2562, 5122, and 10242. B) Values or RMS roughness Rq are reported for the whole set of AFM images with different N. Error bars represent semidispersion of forward and backward scans. Empty squares are from raw AFM data, filled squares are Rq values after zero order image flattening. Lines are just guides to the eye.