Our new article, “Hidden Waviness: When measuring roughness cannot solve quality challenges,” appears in the June 2020 issue of Quality Magazine. This article was written in conjunction with Don Cohen of Michigan Metrology.
Specifications for surface texture frequently focus on surface “roughness”—the finer structures in the texture—often to the exclusion of the “waviness”—the larger structure of the texture. Unfortunately, problems related to sealing, vibration, noise, wear, etc., are regularly caused by issues hidden in the waviness domain. While roughness measurement is clearly important, it cannot prevent problems that lurk outside the roughness wavelength regime.
This article discusses how filtering data to analyze the waviness regime can help to uncover potential quality issues and to control processes. It includes some case studies that effectively highlight issues that could only be addressed by examining longer wavelengths.