Start with what people overlook
Even experienced engineers sometimes misuse calibration balls:
- touching the mounting stem during probing
- using worn or contaminated spheres
- inconsistent point distribution
Practical advice
- Avoid the mounting stem during measurement.
- Clean artifacts properly. Dirty surfaces produce inconsistent results.
- Use appropriate point distribution. More points do not always improve accuracy.
In CT systems, a ruby plate for CT system can be a safer alternative for repeated high-accuracy calibrations because it distributes multiple spheres stably across the scanning field.
Final thought
Avoiding common mistakes is more effective than chasing higher spec artifacts.