Roughness form and waviness measurement by means of light scattering – R. Brodmann

This paper deals with a non-contact, optical measuring method which unites
the assessment of roughness form and waviness in one single instrumenL The
method is based on the deflection of light which leads to a more or less broad
scattered light distribution in the case of roughness and to a shift of the total
distribution curve due to waviness structures. The evaluation of the roughness
signals yields the well-known optical scattering value SN. This value correlates
generally with the profile angle parameter Dq and, in special cases, with the R,
value. The optical measured form and waviness leads, after a calculation,
directly to the geometrical profile which can be compared with a mechanically
traced profile.