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The "smoothness" of a facet is the degree to which polishing lines are visible and therefore it is an important aspect of the finish grade of the facet. Because of the constantly increasing quality demands placed on polished diamond, the problem of smoothness becomes more and more important.
Detection methods
In the past, “Smoothness” of a diamond was checked with a loupe, a microscope or an Avalon. All these methods had disadvantages. Therefore WTOCD developed an upgrade of the Avalon; the Avalon Plus. The degree of visibility of polishing lines is objectively measured and colour-graded according to the HRD -Antwerp standards for polishing grade
Surface Morphology of Diamond
Polishers and graders evaluate the polished surface of a polished diamond in a different way because of the different viewing conditions. This can lead to inconsistency in the evaluation of the polish grade and discussions between graders and polishers. Intelligent automation can provide accurate and consistent information on the polish grade. Therefore this instrument: “the Avalon Plus” has been developed, in the first place for the polishers. The Avalon Plus can be used for: Detection, measurement and grading of the polished quality and for absolute and relative measurements of the facet geometry
Specifications:
- No limits in size for polishing grading
- For measurements of facets up to 10 cts
- Dimensions: L 332 x B147 x H142 mm
- Pc required with NVidia graphic card (minimum GeForce GT240)
- Flat screen required Full HD (1920x1080) (min. Size: 21, 5” )
- Power supply: 230 V, 50/60 Hz
- Weight: +/- 12 kg
- Can be build-in in Pen dragon-bench
Facet geometry
By means of the different icons on the right side of the pc-screen, facet measurements can be executed. A plane through the girdle is the reference of these measurements and not the table like in all other measuring tools. It means that the girdle has to be perfectly round and the girdle must be parallel to the table.
Measurement of the table (totally finished, or in eight or partially polished)
- Input of the diameter of the stone is required
- Results: absolute dimensions edge to edge
- Proportional table size (in relation with the diameter)
- Index angles
crown angle, bottom angles of the pavilion, length of star facets and dimensions of any facet, like for fancy shapes can be measured
No color = line invisible, green to red = slightly visible to clearly visible
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