profilometers

A profilometer is a device that measures the profile of a surface, capturing its elevation relative to a reference plane along one or more directions. Profilometry is used to assess surface roughness, waviness, and texture, and to produce quantitative topography data for engineering, manufacturing, and research.

There are two main families: contact and non-contact. Contact profilometers use a diamond stylus that traces the surface, generating an electrical signal proportional to vertical displacement. They can acquire 2D cross sections or, by scanning, 3D maps, but may scratch delicate surfaces. Non-contact profilometers use optical methods such as confocal microscopy, coherence scanning interferometry, laser triangulation, or structured light to measure height without touching the surface. These are well suited for soft or brittle materials and micro-scale features, with high vertical resolution and fast acquisition.

Measurements yield parameters such as Ra (average roughness), Rq (root mean square roughness), Rz (mean peak-to-valley), or, for 3D data, Sa, Sq, Sz. Profiles are typically compared to design tolerances or reference standards, following international standards such as ISO 4287 and ISO 25178 for morphology and calibration.

Applications span semiconductor wafers, optical components, metalworking and finishing, flat panel displays, automotive parts, and engineering research. In production, profilometry supports process control, wear studies, and surface engineering.

Advances in sensors and computational power continue to improve resolution, speed, and data interpretation, broadening profilometer use in metrology laboratories and production lines.