Proportion Analyzers (5.12)
The proportionscope, first designed and manufactured by GIA in 1967, is an instrument that casts a silhouetted image of the diamond It allows us to check the proportions of the stone in question. More current technology has largely replaced this but still a handy gemological tool to include in one’s lab.
If one's budget allows the Sarine diamond proportion analyzers are a great addition to the arsenal of tools and instruments for professional diamond dealers.
Left courtesy of: http://www.minedirect.com/EnlargedPages/Equipment/Misc/PS-1.html
Right: Courtesy of Kassoy: https://kassoy.com/sarin/sarin-diascan-diamond-cut-evaluator.asp
Sarine offers an array of sophisticated proportion analyzers for diamonds: https://sarine.com/