Start with what usually causes the problem
Large 3D scans often show volumetric distortions.
People immediately blame the scanner hardware or software.
Most of the time, the cause is subtle:
- artifact instability
- uneven point distribution
- thermal drift
- environmental vibrations
Engineer tips
- Always secure the calibration artifact firmly.
- Use distributed reference points: a ball bar or ball plate is better than a single sphere.
- Reposition and rescan to verify repeatability.
For industrial CT, a ruby plate for CT system is often preferable because it maintains geometric stability and allows volumetric errors to be clearly identified.
Final thought
Volumetric errors rarely appear out of nowhere.
Consistent calibration practices, correct artifact choice, and environmental control prevent most issues.