PRESIDIUM Synthetic Ruby Identifier User Handbook Manual page 18

The testing is performed under the lid of the Synthetic Ruby Identifier
where a testing area is marked by a concentric-circled base platform
with a Photo-detector in the centre and a protruding overhead LED
light source (Fig 2.3).
Fig.2.3 The interior testing area inside the device
The following instructions will guide you through testing loose
gemstones and mounted jewelry.
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