Modern measurement equipment include hand tools, CMMs (Coordinate-Measurement Machine), machine vision systems, laser trackers, and optical comparators. For hand tools, see Caliper and micrometer. A CMM is based on CNC technology to automate measurement of Cartesian coordinates using a touch probe, contact scanning probe, or non-contact sensor. Optical comparators are used when physically touching the part is undesirable. Optical comparators can now build 3D models of a scanned part and internal passages using x-ray technology. Furthermore, optical 3D (laser) scanners are becoming more and common. By using a light sensitive detector (e.g. digital camera) and a light source (laser, line projector) the triangulation principle is employed to generate 3D data, which is evaluated in order to compare the measures against nominal geometries.
Data is collected in or compared to a print. A print is a blueprint illustrating crucial features. Prints can be hand drawn or automatically generated by a CAD model.