Reading Test Results With Your Presidium Refractive Index Meter - PRESIDIUM PRIM II Manual Del Usuario

3. READING TEST RESULTS with your Presidium
Refractive Index Meter II
The test results are indicated as follows:
• A Refractive Index Reference List is provided for
easy reference to end-user. This list comprises
common gemstones available in the market. The
gemstones are arranged according to descending
Refractive Index. Please refer to attached table.
• The list includes the range of refractive index of
gemstones with respective tolerance provided in
brackets.
• The tolerance in refractive index is due to the
tolerance from the photo-sensor used.
• Example: The refractive index for sapphire is 1.757
(-0.016) – 1.790. The reading in bracket refers to the
tolerance. In other words, the R.I. reading of sapphire
from the unit ranges from 1.741 – 1.790.
• In case of a borderline reading, clean the stone and
pad again before the next test and/or move stone
slightly off center. By repositioning the stone, a
distorted reflection from a scratched area of the
surface may be avoided. Repeat the test.
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