GOLDANALYTIX GOLDSCREENPEN Bedienungsanleitung Seite 29

Depending on the conductivity of the material, the GoldScreenPen penetrates the respective
metals or alloys to different depths. With highly conductive materials such as silver [61 MS/m],
the device penetrates less deeply than with alloys from the medium (gold 999 [45 MS/m] or gold
986 [approx. 25.5 MS/m]) and low conductivity range (e.g. Krugerrand [9.7 MS/m]). The
penetration depths are relatively high, considering that most gold- or silver-plated layers are only 10
to 60 μm thick. The penetration depth of the GoldScreenPen determines the size up to which
precious metal objects can be measured. In principle, you can also measure 1 kg silver ingots
with the device - there will be a conductivity value. However, with such large objects, there is a
risk that the forgers apply thicker layers of precious metal around the fake metal core.
Therefore, one should always combine several suitable testing methods, especially for objects
over 1 ounce. For bars from approx. 50 g, we recommend the additional use of the ultrasonic
method (Goldanalytix BarScreenSensor). For objects up to 1 ounce, however, the penetration
depth is sufficiently high to detect counterfeits.
Please also have a look at our website www.gold-analytix.com/knowledge for more
information about the correct procedure for the non-destructive testing of precious metals.
However, absolute certainty, especially regarding the exact composition of the test objects, can
only be provided by a destructive, chemical analysis.
Irregular and immobile objects: Another major advantage of the GoldScreenPen is the ability to
measure irregularly shaped or individual metal objects. A typical example is the differentiation of
high-quality and merely silver-plated cutlery: High-quality silverware (hallmarks 800-999, i.e. 80-
99.9% silver content) can be clearly distinguished from hotel silverware of class A (hallmarks
90/100/110; base material: nickel silver, brass, or other copper alloys) and B (e.g. hallmarks 60 or
80; a wide variety of base materials), since in these cases the conductivity ranges are approx. 5-
25 MS/m, depending on the base material. The GoldScreenPen as a mobile device enables
punctual testing of large, immobile metal objects, e.g. in scrapyards. Another field of application
is the differentiation of high-quality pewter from cheap imitations, e.g. made of zinc.
Special cases:
 Older coins/bars
Older coins/bars (defined here as coins/precious metals before World War II) and especially
objects from the 19th century may vary in their composition. Although the gold content is
correct, some coins may have variations in the remaining composition. Due to non-optimized
manufacturing and analysis conditions at the time, such coins may have been contaminated with
foreign metals, altering the conductivity of the coin and often making reliable authentication of
older coins and bars with the GoldScreenPen not possible.
 Fine silver coins
Fine silver coins with a fineness of .9999 (Maple Leaf or Kangaroo) have a higher conductivity
value than .999 coins. The reason for this is that even one per mile of foreign metal in the .999
gold coins can cause a decrease in conductivity. This sensitivity is most noticeable in coins with
deep mintings or high edges. Due to the higher fineness, 9999 silver coins or bars may be in the
range of 62 to 64 MS/m – such values are above the target value of silver, but are perfectly fine
due to the measurement configuration.
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