Figure 3

Surface roughness parameters registered on the graphite pendant with confocal microscopy: (a) Double boxplots showing the four more informative parameters registered with confocal microscopy on each surface of the pendant; (b) 3D views of the surface of flat side of the pendant produced by confocal microscopy. The 3D images in the right column are filtered with a Gaussian filter with a 250 µm cut-off. The positive skewness of the distribution is visible on the grey surface on the z scale representing the distribution of the height measurements.