PRESIDIUM Gem Indicator PGI Manual Del Usuario página 9

For mounted jewelry or gemstones:
Hold the jewelry or mounted gemstone with one hand and
the tester with the other hand (Fig. 2.3).
For proper operation of the tester, the thumb and index
finger must always be placed on the metal grip of the
tester.
Press the probe tip of the tester against the gemstone.
Ensure the tip is fully depressed for consistent pressure
between the tip and the gemstone.
Note: Care should be taken when testing mounted
jewelry. Users must ensure that the stones are securely
mounted before conducting the test as the gap between
the stone and setting might lead to an inaccurate reading.
For loose gemstones:
Hold the gemstone with one hand while holding the tester
with the other hand (Fig. 2.4).
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Fig. 2.3
Fig. 2.4
The probe tip must be placed at a right angle or
perpendicular to the facet of the gemstone for an
accurate reading.
Tests should be conducted on the table of the gemstone.
In the event of any doubt, you may also test on the girdle
of the gemstone.
For proper operation of the tester, fingers must be placed
on the metal grip at all times.
To achieve optimum test accuracy involving very small
mounted gemstones (1.22mm exposed diameter and
below), it is extremely important that no contact is made
on any metal/jewelry setting part of the jewelry.
To achieve optimum test accuracy involving very small
gemstones (10 points and below), it is important to allow
the gemstone to cool down for 5-10 seconds in between
tests.
It is advisable to conduct multiple tests on different points
on the gemstone as thermal conductivities may differ
slightly along different crystal axes of the gemstone.
Cleaning of probe tip
Please note that if the tester is being used for the first
time, or if the tester has not been used for more than a
week, it is advisable to clean the probe tip using a piece
of paper.
A clean probe tip helps to attain consistent and accurate
readings.
To clean the probe tip,
• Ensure the unit is switched off.
• Hold the probe pen with the pen tip forming right-
angle (90-degree) with any paper or stone rest.
Gently move in circular motion without retracting the
tip (Fig. 2.5).
• Repeat the same motion several times. The cleaning
process is completed and the tester is now ready for
use.
Fig. 2.5
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