FAQ

TESTERS (PDMT, PMuT, PGT, PDT & PRM)

1. Why do I get inconsistent readings from my testers?

    In general, inconsistent readings could be caused by the following factors:

    a) Variation of ambient temperature
    Solution:
      • Gems/jewellery pieces should be tested at the room temperature
      • Always allow the stone to cool down for a while before conducting subsequent tests

    b) Inconsistent pressure when applying probe tip
    Solution:
      • The probe tip must be held in perpendicular (90º) to the table of the stone and apply consistent pressure. The probe tip should be fully retracted.

    c) Oxidation of probe tip/dirt on probe tip
    Solution:
      • Clean the tip occasionally, dirt stuck on the probe tip will lead to inconsistent test result.

    d) Moisture on stone
    Solution:
      • Clean the stone with a dry tissue

    e) Weak battery
    Solution:
      • Change to a new battery when the [L. Bat] LED lights up

 

2. Will the size of the gemstones affect my test results?

    Smaller stones conduct less heat from the probe tip. Hence, the readings displayed will be slightly lower. However, readings will still be within the reading zone.  

3. I find it difficult to hold small stones during testing. What should I do?

    Hold the stone with a Push Tweezers or place the stone on the metal tray (Optional accessory from Presidium).

 

4. How do I read the test results on the meter display of my PGT/PDT?

    Please refer to the figure below. For a given position of indicator, all the gemstones that fall along the indicator and within the
    white strip are possible gemstones. Please note that the readings will fluctuate. Kindly refer to item 1.

 

    For the figure below, the possible gemstones are Tanzanite, Aquamarine, Quartz, Amethyst or Citrine.

 

 

5. Why do I get inconsistent readings for loose stones from PGT/PDT?

    When heat is conducted from the probe tip to the stone, the meter indicates the heat conductivity of the stone. The reading falls
    once the heat saturates. It is advisable to place the stone on a metal tray (optional accessory) to enhance heat conductivity.
    Always allow the stone to cool before subsequent tests.

 

6. Why doesn’t the meter indicator return to zero on my PGT/PDT?

    This could be due to static charge on the surface of the meter. Use a wet tissue to wipe the surface of the meter to discharge
    the static electricity.

7. Why can’t the reflectivity reset to zero on my PRM/PDT?

    Ensure that the protective cover is replaced by the cylinder before pressing the Display button. When the protective cover touches the aperture of the light ray and sensor, some light will be reflected and the 7-segment LED will display a reading.

 

8. Why do I get inconsistent readings from my PRM/PDT?

    This is due to inadequate polishing and uneven surface of the stones.

9. Why do I sometimes hear intermittent beeping when testing gemstones with my PDMT/PMuT?

    PDMT/PMuT has a built-in metal detector. Whenever the probe tip touches a metal surface, an audible intermittent beep will sound. This is only applicable to mounted gemstones.  

 

10. Why does moissanite register as diamond when using my PMuT with a metal tray?

    a) Forming incomplete test loop
    PMuT provides results by using both the electrical and thermal conductivity property of gemstones. Moissanite is
    conductive while diamond is not. Hence, it is important to place the stone on a metal tray and to hold the metal tray
    with one hand and the tester with another to form a complete electrical loop. Otherwise, moissanite will not be
    conductive and PMuT will register diamond.

    b) Property of moissanite The uneven distribution of impurities in moissanite could also cause the above observation. Hence, try to take a few tests at the girdle and different locations on the table for better results.

11. Why doesn’t my tester work when powered with an AC adaptor?

    Only use the AC adaptor supplied by Presidium, otherwise the polarity of the plug might not be suitable. Remove the AC adaptor from the inlet and try operating it with batteries. If the tester is operating normally using batteries, the AC adaptor is not working. If the tester is not working when using batteries, the tester is faulty. In the event that the tester is not working when using batteries, please send the unit to the authorized dealer nearest to you for repair.

GAUGES_(PDG, PEGG and PGCG)

1. My Presidium Electronic Gemstone Gauge (PEGG)/ Presidium Dial Gauge (PDG)/ Presidium Gem Computer Gauge (PGCG) is not accurate.

    If your unit cannot be reset to zero, this could be due to dust or small particles deposited on the base anvil. Please clean/wipe the base anvil to ensure that no particles are deposited on it.

    If the gauge has been dropped, the Projecting Probe, Slider Anvil & Base Anvil will be deformed.

2. Can I apply oil/grease on the Slider to smoothen it sliding?

    No. Dust will stick on the grease, which will eventually jam the slider.

3. Why can’t I connect my PGCG on my Mac computer?

    PGCG is currently only configured for Microsoft Windows platforms.

 

4. How can I measure a diamond’s depth when it is mounted on a ring?

    Diamond rings usually have a small hole on the inner part of the ring. In this case, use the jewelry attachment included with your Presidium gauge. This jewelry attachment will fit through the hole and touch the bottom tip of the diamond.

5. My PGCG unit doesn’t have the gemstone information I need in my measurement.

    PGCG unit only comes with 73 basic gemstone data. Use the mini disc included to access data for 133 additional gemstones.

 

SCALE (PCS-50LFT, PCS-100)

1. Why do I get inconsistent readings from the Presidium Carat Scale (PCS)?

    Inconsistent readings occur when the scale is placed in a vibrating environment or on an uneven surface.

2. What should I do when “EEEEE” appears on my display screen?

    The scale’s weight capacity has been overloaded. Limit your load to 50ct/10g for PCS-50LFT and 100ct/20g for PCS-100LFT.

3. Which are the applicable states for my PCS-50LFT?

    All Presidium scales are factory pre-calibrated. Currently the PCS-50LFT is Legal For Trade for New York, California, Arizona, Florida, and Texas.

4. Why doesn’t my scale show accurate readings?

    Each country has its own gravitational discrepancies. Check that your scale has been calibrated for your location.

ENGRAVING MACHINES (PIREM, PJEM)

1. Why are my engraved letters distorted?

    The letters are distorted due to excessive pressure exerted on the level. Do not push the level all the way down, as the engraving diamond will sink too deeply into the metal surface during engraving.

    As a rule of thumb, push the level down lightly until it reaches a point where the level comes to a stop. At this point, the engraving diamond is at the surface of the ring. Exert slightly more pressure and start engraving. Practice makes perfect!

2. Why are my characters deformed while engraving?

    For PJEM, check that the ratio setting on the pantograph arm and vertical carriage is properly set.

3. Why does my ring move during engraving?

    The ring is not securely fastened. For regularly-shaped rings, take note of the width of the ring and use the appropriate self-centering jaw. Use the red self-centering jaw for narrower rings and the blue one for wider rings. Ensure that the ring is securely fastened by using the chucking knob.