Measuring Surface Roughness

Technical Data Sheet #14

This is the C.E. Johansson Multimi. It is a combination two beam and multibeam micro interferometer. This special microscope is capable of measuring surface roughness down to a small fraction of a microinch.

Photograph from Interferometer Shows the Surface Finish of a High Quality Ball

Surface roughness is usually measured electronically by tracing a very sensitive needle shaped diamond probe over the test surface. The difficulty of guiding a probe over the surface of a ball makes this method of measurement impossible for the ultra fine surface finish of high quality balls.

Bal-tec uses the most sophisticated techniques yet developed to make these measurements. The instrument we use is the C.E. Johansson Multimi, which is a combination two beam and multibeam micro interferometer. This instrument sends a monochromatic light beam down to the surface of the test ball, and then compares the reflected waves with a test plate to determine the surface finish to the smallest fraction of a microinch. This system works just as well on very small balls as on normal or very large ones.

For research and development, or where documentation of quality is required, this instrument has photographic recording capability.