Filters | Surface Roughness Terminology

λs, or 'S-filter', is a filter eliminating the smallest scale elements from the surface (low-pass filter). This filter is equivalent to the cutoff value λs in JIS B 0601-2001. In the case of contact-type surface roughness measurements, noise due to edges is removed.

λc, or 'L-filter', is a filter eliminating the largest scale elements from the surface (high-pass filter). This filter is used to remove undulations and other lateral components from the surface, and thus allows for the extraction of only the roughness components. L-filter is equivalent to the cutoff value λc in JIS B 0633-2001.

λf, or 'F-operator', removes form from the primary surface. This filter is equivalent to tilt correction, suppressing the nominal surface texture characterization.