Sarin color grader tested by Japanese Lab

[Garry H (Cut Nut)]

I hope the link came out - I am new to FireFox and the menu is all different

here it is again anyway
http://gaaj-zenhokyo.com/practicality-colibri%E2%84%A2-diamond-colour-grading-product-sarin

You can easily register to see all the charts - a fairly thorough report:

Practicality of Colibri™, a diamond colour-grading product by Sarin
by GAAJ-ZENHOKYO laboratory: Dr. Jun Kawano, Kunihiro Saikyo (FGA, CGJ, GIA.G.G.)
August 31, 2009



GAAJ-ZENHOKYO Laboratory measured about 14,000 diamonds on the instrument - Results and Conclusions appear here.
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As shown on the diagram, a distribution of the results of the diamonds graded as the same colour at our laboratory makes a gentle curve with one peak. Each peak of the distributions falls in the range of values corresponding to the colour grade of pre-set GIA system, and 55-70% of the stones measured are included in the range. Estimate the error on ColibriTM ±1/2 and extend the effective width ±1/2 over the original, then more than 80-90% of measured diamonds fall in the range. For example, about 60% (704 pieces) of diamonds graded as F colour (1,164 pieces in total) fall in the range between 3.01 and 4.00 and about 90% (1,047 pieces) show the values between 2.51 and 4.50. Taking into account that each colour essentially has a certain range, and it is highly possible that natural diamonds in cape colour might contain a slight amount of hue, we can conclude that the results above are accurate enough for practical use.The report link

 

[Karl_K]

Interesting.
To be really useful it has to detect stones it can not grade properly and raise an error.
For example over med. fluorescence and colors other than cape and positioning changed the results so it should detect those and raise an error message.
A grading machine should do all it can to never give a false value, if it can't get a good value it should raise an error.
This has been done in industrial applications for for decades so it isn't like they shouldn't know this.