Nomenclature and Symbols used for SurfaceProfileAcquisition

Asperity: a general hooking surface feature, can be a hole or a protrusion. Geometrically speaking it is a significant peak-to-valley distance. Significant with respect to the spine/claw tip diameter.

Average surface height: is the ideal surface plane minimizing the distance from the real surface in the least square sense.

Average surface roughness, Ra: is the standard parameter used in technical drawing. Integral = area

Hole: a surface depression, a valley, below the average surface height.

Protrusion: a surface peak, over the average surface height