PRESIDIUM Synthetic Ruby Identifier Manual Del Usuario página 25

With the ring hung within the Ring Guide area, use the lever to lower
the LED light source to secure the stone over the Photo-detector
(Fig 2.7).
Fig.2.7 Place open-back ring jewelry on the Ring Guide on the LED
light source and push the LED light source down to secure the stone
against the Photo-detector
If your gemstone is mounted with open-back setting in other types of
jewelry that cannot be placed over the Ring Guide, place the jewelry
onto the base platform, with the stone covering the Photo-detector and
lower the LED light source to secure the jewelry in place for testing.
Ensure that the Photo-detector is completely covered by the gemstone
so that the emitted wavelength is through the stone material.
Should the Photo-detector not be completely covered by the
gemstone, the emitted UV light will not be able to pass through the
stone, reaching the Photo-detector instead and will give an inaccurate
reading of the UV light transmittance ability of the stone material.
Close the lid and press the "Start Test" button.
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