The basis for the Rk parameters is the roughness profile that is generated by filtering with the robust Gaussian filter in accordance with DIN EN ISO 16610-31.
A special regression line on the Abbott curve of the roughness profile splits the curve into three areas which are used to calculate the Rk parameters:
Core height Rk is the height of the core roughness profile.
Reduced peak height Rpk is the mean height of the peaks protruding from the core roughness profile.
Reduced pit depth Rvk is the mean depth of the pits protruding from the core roughness profile.
Rmrk1 and Rmrk2 (previously Mr1 and Mr2) designate the smallest and largest material ratios of the core roughness profile.