Accuracy is a scanner property
The accuracy of a scan-based measurement is set by the scanner — its stated volumetric accuracy, its resolution, the calibration state and the quality of the capture. Inspection software evaluates the geometry the scan contains; it cannot improve it. The first question is therefore not which software but which tolerances you need to verify, and whether the scanner's stated accuracy leaves enough margin against them.
A common rule of thumb in metrology is that the measuring uncertainty should be a small fraction of the tolerance being checked. Apply it to the scanner's specification sheet before anything else.
Resolution and feature size
Resolution (point spacing) decides the smallest feature you can fit reliably. A hole needs enough points around its circumference to define a circle; an edge needs enough points on both faces to locate the intersection. If your drawings are full of small holes and thin walls, resolution matters more than volumetric accuracy over a large part.
Part size, surface and environment
Hand-held structured-light or laser scanners cover medium parts quickly; fixed structured-light systems with a turntable give very repeatable results on small parts; large parts often need photogrammetry targets for global accuracy. Shiny, dark or transparent surfaces may need matting spray, which has to be accounted for in the result. Shop-floor temperature and vibration affect both scanner and part.
- Small, detailed parts → fixed structured light with turntable
- Medium parts, mixed geometry → hand-held structured light or laser
- Large assemblies → photogrammetry-assisted scanning for global accuracy
- Reflective or dark surfaces → plan for matting spray and its thickness
Workflow fit and open data
Every scanner ships with its own capture software; what matters for metrology is that it exports an open mesh (STL, PLY, OBJ) with the point density you need. That keeps the inspection software independent of the capture device — the same CAD model, the same DMIS program and the same report template work whichever scanner captured the part. Ai-Inspect is scanner-agnostic for this reason and accepts meshes from Creaform, GOM, Shining3D, Artec and other devices.
A short checklist
Before buying, scan a representative part with the candidate scanner and run your real inspection on it. Check the coverage of the features that carry tight tolerances, compare a few results with a CMM measurement of the same part, and look at how long the whole workflow — capture, alignment, evaluation, report — takes for your operators.
- Stated accuracy versus your tightest tolerances
- Point spacing versus your smallest features
- Export to STL/PLY/OBJ without vendor lock-in
- Capture time and operator skill required on your parts
- Calibration procedure and its frequency