Surface Roughness & Finish

One of the most common applications for profilometers of any type is the characterization of surface roughness. An optical profilometer is an excellent choice for surface roughness measurements. With one scan, a 3-dimensional surface profile is obtained that provides a wealth of parameters to specify the surface characteristics. Common places to find optical profilometers are machining and tooling industries, but also in lapping, polishing, and optical businesses.

For surface roughness and finish measurements, contact our surface profile experts.

Filmetrics offers free trial measurements - results are typically available in 1-2 days.

Surface Profile Example

In the figures below, we are measuring the surface profile of a metal part as it is polished through 4 passes. Fig. 1 indicates the number of polishing passes that have been applied to each corresponding side, with the roughest surface finish having only 1 pass and the smoothest having 4 passes.

Each side was measured on the Profilm3D with a 10x objective at the 4x zoom setting to assess the surface roughness. Fig. 2 shows the four scans from each side; it is clear to see that the surface is getting smoother with each polishing pass.

To put the changes in roughness in numbers, we can use comprehensive roughness parameters such as Sa and Sq. Plotting the surface roughness versus the number of polishing passes (fig. 3) shows how the surface roughness decreases with increased polishing. The surface roughness decrease slows down with the number of finishes. It is also clear from these data that the fourth polishing pass added only a marginal improvement.

Measurement Setup:

3D Images:

Measurement Result: