Surface roughness measurement can be made using an optical 3D system or a tactile probe system. A tactile line-based profilometer captures a single or series of 2D profile across a surface (R values) whereas an optical 3D metrology system captures an entire area providing the calculation of advanced surface parameters or (“S” values)  that are areal based and 3D providing more accurate details about the surface and its function.

An optical system is non-contact and will not cause surface damage and is not subject to stylus wear which could affect accuracy. An optical system has very fine vertical and lateral resolution enabling measurement of fine surface details whereas a line-based system provide high Z-resolution with lateral resolution being restricted by the stylus tip size. 

Optical systems can also be more readily automated and used within the manufacturing process, reducing the risk of human error that could affect the result. Modern optical systems such as the FocusX from Bruker Alicona provide one click roughness measurement removing the need for metrology knowledge.

Optimax provides both the optical non-contact system from Bruker Alicona and tactile systems from Mahr and will recommend which solution is best for the application.