What geometry measurement tells you
Many parts are defined by their shape at a scale too small for calipers and too delicate for a touch probe: cutting edges, threads, implants, connectors, micro-moulded features, seal lips, tread patterns, weld beads. Geometry and shape measurement extracts their dimensions from a 3D surface map and checks them against the design.
From 3D map to dimensions
A single scan records the whole feature. Any number of profiles can then be extracted and analysed:
- radius of curvature of fillets, edges and curved surfaces;
- relative angles between faces;
- distances, lateral dimensions and mean diameters;
- contour analysis, fitting lines and arcs to a profile to dimension it fully.
Because the full surface is stored, more dimensions can be extracted later without re-measuring the part.
Comparing with CAD
For machined, moulded and printed parts, the most complete check compares the measured surface with its CAD model. The deviation at every point shows where material is missing or in excess, not just whether one dimension passes. With tolerance limits set, the software decides pass or fail automatically, as in NANOVEA’s machined parts inspection.
Cutting edges and tools
Edge preparation strongly affects tool life. Edge geometry measurements on drill bits and cutting tools include rake and wedge angles, edge rounding, and the edge segments Sα and Sγ, the distances from the apex to where the rounding meets the flank and rake faces, and their ratio K, which describes whether the edge is symmetric or skewed toward one face. Steep-flank capability up to 87° lets the sensor follow the edge profile without shadowing.
Why non-contact for shape
A touch probe’s tip cannot resolve radii smaller than itself, and its force can deflect thin or soft features. Camera-based methods struggle on reflective or steep surfaces and rely on focus algorithms. Chromatic confocal sensing measures height directly from the reflected wavelength, so lateral and height accuracy come from the sensor’s optics rather than from pixel counts or stitching. The same measurement works on polished metal, ceramic, polymer, rubber and tissue.
