- Joined
- May 1, 2008
- Messages
- 3,563
It's precision (fluctuations): These are non-contact scanners. The diamond rotates on a stage while the facets are mapped. Video example here. That's where fluctuations may occur. Connecting this to diamond cutting precision; our fundamental proposition requires us to eliminate all ground vibrations. We sink the legs of our polishing mills several feet into foundations. We even removed ourselves from areas with traffic/airports, because a truck passing by or plane landing in the area will affect the precision of our crafting goals. Logically, the same kind of fluctuations can affect the subsequent scans.I'm curious, is the source of this uncertainty understood? Is it actually an accuracy issue (which could potentially be overcome by improved calibration techniques) or a limitation in the measurement precision (reproducibility issues due to randomly distributed fluctuations)? It may be possible to improve precision by making repeated measurements (and averaging, if normally distributed). Or is the limitation due to quantization error (i.e., sensor resolution)?<ENGINEER MODE = OFF>
And admittedly, we're wine snobs in all of this. In the bigger picture the stages, lighting modules and lenses are tremendously accurate (IFF the stages are spotless and you regularly calibrate). It's evolved to the point where symmetry grading of facet meet points, historically done by the human eye, has shifted to scanners. As for your suggestion of repeated measurements, that's happening. When we request an improved scan the lab frequently has a backup scan (or two) that turns out to be more representative. But in some cases we either remove the diamond from market and ship it back, or just accept "close enough."
Swerving back to the GIA topic: Proportions output is far simpler than generating detailed 3D imprints. I'd argue that normal scans are already "close enough" to publish averaged 2D proportions to within 0.1 degree.
BTW, when I grow up I want to be an engineer.