Goldanalytix GOLDSCREENPEN, Instruction Manual

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21. Important Hints for Measuring with the GoldScreenPen
Disruptive factors: We recommend dropping all your mobile devices (i.e. smartphone, mobile
phone or flash drive with wireless access) at least 1 m far away from the testing device due to
the inductive eddy current principle of the device. The relatively high radiation density which is
especially high during connection setup can lead to false measurements. The latter can be
recognized by strong deviations or oscillations of the value. After restarting the device can be
used without further restrictions. Wireless LAN / Wifi or Bluetooth do not influence the
measurement.
IMPORTANT: Always wait 2 to 3 seconds in between the respective measurements, in order to
let the device calibrate itself. If you lay the coins onto the device to quickly, it may happen that
the values are distorted. This auto-calibration process can take a bit longer sometimes. Should
you be unsure whether the displayed value really is the correct one, take the object off the
device and wait some seconds more before putting it on again.
Please keep the temperature of the device and coins in mind - ideally, they should be about
22 °C (+/- 2°C) - the conductivity values depend on the temperature. So also make sure that you
do not hold the coins and bars in your hand for too long before performing the measurement, as
they would be too warm and the measurement results can therefore be false.
Penetration depth of the GoldScreenPen: Depending on the conductivity of the material, the
GoldScreenPen penetrates into different depths into the precious metals. In case of highly
conductive materials like silver (conductivity = 61 MS/m), the penetration will not be as deep as
in case of metals of the middle zone (.999 gold [45 MS/m] or .986 gold [about 25.5 MS/m]) and
the low conductivity zone (e.g. Krugerrand alloys at 9.7 MS/m). In case of
silver , you can expect
about 150 µm penetration depth , whereas in case of the Krugerrand alloy the penetration
depths is up to 500 µm (0.50 mm). However, this is relatively deep, if you keep in mind that
most gold- or silver-plated layers are only 10 to 60 µm thick. It depends on these numbers, up to
which size the precious metal objects can be measured. Generally speaking, you can measure
1 kg silver bar with this device - there will be a conductivity value. However, in case of such big
objects, it is very possible that the forgers apply much thicker precious metal layers around the
fake core. Then the GoldScreenPen will not give you a reliable answer. "Smaller" objects are
normally penetrated completely by the magnetic induction field - in case of bigger ones (from 1
ounce on, according to their geometry), forgers would have to use very little amounts of fake
material in order to not get caught. It is questionable if this is lucrative for them - however, it is
possible that from this size onwards, there are objects with a deeper core.
This is why you
should always use more than one suitable testing method, especially for objects of over 1
ounce.
In case of bigger bars (from 50/100 grams), you should definitely use ultrasound as well
(Goldanalytix BarScreenSensor).
Testing objects should exhibit a thickness of at least 0.6 mm to 1 mm ; blisters can have a
thickness of up to 0.25 mm . Not every material shields in the same manner. If there are metallic
components in the supposed plastic package, no reliable or convincing measurement can be
guaranteed. Our test measurements with e.g. NGC packages have shown that they are too thick