Kontaktprofilometer

A kontaktprofilometer, or contact profilometer, is a measurement instrument used to characterize surface topography by tracing the surface with a stylus in physical contact with the material. It is one of the common tools in metrology for obtaining quantitative profiles and roughness data across various materials and applications.

The measurement principle involves a diamond-tipped stylus resting on a precision X–Y translation stage. As the stylus moves along the surface, vertical deflections caused by surface height variations are converted into electrical signals by a displacement sensor, such as an LVDT or capacitive sensor. The recorded vertical motion constitutes a profile line (2D), and with scanning stages it can generate areal topography (3D). The technique is direct, providing high-resolution height data but can introduce contact forces on the surface.

Typical components include the stylus or probe, a displacement sensor, motorized translation stages, drive electronics, and data analysis software. Some instruments offer contact force control to minimize damage, as well as line-scanning and raster-scanning modes to capture single profiles or areal maps of surface texture. Calibration and tip wear monitoring are important for maintaining accuracy.

Measured outputs commonly include roughness and texture parameters. In 2D mode, the most used are Ra, Rq, Rz, and Rt; in 3D areal measurements, parameters such as Sa, Sq, and Sz may be reported. Results are usually presented as profiles, areal topographies, and statistical distributions, with standards such as ISO 4287 and related profilometry guidelines informing parameter definitions and measurement procedures.

Applications span manufacturing quality control, metalworking, coatings, plastics, and electronics, where precise surface characterization is required. Advantages include high vertical resolution on hard surfaces and direct height measurements, while limitations involve tip wear, potential surface damage on delicate samples, and the need for appropriate calibration and operating conditions.