. Also, given Figures have different orientations of component (0), resulting different contact areas with the surface. Is it intentional? If so, how is it related to the sweep direction? If not, why is it different?  Figure 0 is impossible to be understood - possibly because the coordinate system for both conditions are different. Still, this Figure must me improved!  The probe position seems to be changing between trials in the lateral sweep, but not in the longitudinal 