Watchmakers rely on CSI Coherence Scanning Interferometry

The surface quality of watch and clock parts depends on white-light-interferometry. Optical metrology is gaining importance for quality assurance of precision micro-parts. Fast, high resolution measurements using a non-contact, non-reactive (zero mass loading) optical technique are particularly appealing for micro-parts. This story takes a closer look over the watchmaker’s shoulder to see, how white-light interferometry can support their precision engineering. In contrast to several other optical surface metrology methods, such as fringe projection or focus variation, white-light interferometry can be used for measurements on both rough and optically smooth surfaces.

3D topography of watch components

Evaluate steps, flatness and parallelism on adjacent surfaces on watch parts and other precision engineered parts. A minute wheel drive from a watch shown as 3D topography profile. To verify the manufactured quality, the surface roughness on the inclined area, which is about 100 x 300 μm2 must be measured. Tactile measurement methods would cause problems due to the geometry of the measurement area. On the other hand, optical techniques such as white-light interferometry allow the topography to be captured within a matter of seconds.