Presidium Dial Gauge Manual - iGem Instruments
How to Use
Dual Dial Face
Dial face with mm measurement and carats conversion scales.
Measuring range - 0 to 23 mm In the first revolution, when the pointer travels from 0 to 0 , it reads 0-10 mm on the millimeter scale. At the same time, it shows a direct carats conversion of 0.01 - 3.65 on the RED colour carats conversion scale. For example a round brilliant cut diamond measuring 4 mm diameter will have an estimated weight of 0.23 carats (reading directly from the RED number).
In the second revolution, it reads 10.1 - 20 mm and a direct carats conversion of 4.21 - 29.14 on the BLACK colour carats conversion scale. For example, a round brilliant cut diamond measuring 12 mm diameter will have an estimated weight of 6.29 carats (reading directly from the BLACK number).
In the third revolution, the pointer will not go any further after 23+mm, and it reads 20.1 - 23 mm. No conversion was provided for stones above 20 mm.
Resolution - 0.10 mm / division
Instrumental Error - +0.05 mm
Note : The calculation of mm / carats conversion was based on data from the PRESIDIUM GEM WEIGHT COMPUTER for round brilliant cut stones with medium girdle thickness. However, this feature is only applicable to proportional round brilliant cut diamond with depth equal to 59.75% of the diameter.- 2 Rang Indicator
Indicates each time the pointer passes " 0 " 10 mm or 20 mm should be added to the reading. - Slider
- Base Anvil
- Slider Anvil
- Wedge Shape Points
- stones mounted in rubbed over settings. (Fig. A)
- interiors of empty settings. (Fig. A)
- ring size. (Fig. B)
- Projecting Probe
- depths of mounted stones. (Fig. C)
- widths and lengths of larger, loose stones, specially fancy cuts.
- Jewellery Attachment
- in high settings. (Fig. D)
- in settings with small holes.
- Pointer
- Fine Adjustment Knob For Zeroing Dial Face
- Dial For Ring Size
The slider is controlled with the thumb. Gauge should be held in the palm of either hand.
For measuring :
For measuring :
For measuring depths of stones :
Turn the knob of the instrument either clockwise or anticlockwise to realign pointer to " 0 " position when necessary. Zeroing adjustment is necessary when using with jewellery attachment.
To determine the finger size of a ring. Measure from the wedge shape points as in (Fig. B) and read from the dial for ring size in the center.
Caution: Do not attempt to dismantle this instrument and/or lubricate it.
