6212C Manual Version 15_22 Rev 07-19.docx
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There are other examples of unique surface roughness pattern from various machining operations (swirl
pattern, repeating groves, random / fractal, predominant peaks, predominant valleys) that uniquely affect the
shape of the scattered light pattern.
Within any machining operation, as surface roughness increases, the specular portion of reflection decreases in
intensity and the scatter portion of reflection increases in intensity. Lasercheck measures that entire pattern of
specular and scatter reflection to determine roughness of a surface.
Requirement for Calibration of Lasercheck to Specific Machining Operation
The images below are basic optical schematics of Lasercheck showing laser source, beam reflecting optics, and
layout of detectors. In both cases Lasercheck is on surfaces with the same Ra roughness value, but different
surface pattern from different machining operation. Note the detectors are arranged in a line. They measure all
of the scattered light from the directional surface. They measure only a portion of the scattered light from the
non-directional surface.
Lasercheck will measure different signals and calculate different roughness for these two surfaces with identical
Ra. The surface roughness pattern (machining operation) and resulting scatter pattern therefore must be an
integral part of any Lasercheck calibration.
