Testing Device for Coins and Bars (GoldScreen Sensor)

Testing Device for Coins and Bars (GoldScreen Sensor): authenticity test via electrical conductivity

• Function: Authenticity testing of coins and bars made of precious metal
• Suitable for: Gold, silver, platinum and palladium
• Measuring principle: electrical conductivity, shown as a numerical value in MS/m on the display
• Handling: Place the piece on the device, read the measured value and compare it with the typical value of the alloy
• Manufacturer: Goldanalytix, made in Germany

With the naked eye, a well-made counterfeit can hardly be distinguished from genuine precious metal. Some counterfeits even have the right weight and carry an outer layer of real gold. The GoldScreen Sensor from Goldanalytix therefore tests a property that cannot be seen: the electrical conductivity of the metal. This way, you replace a mere impression with a measured value you can follow.

How the measurement works

You place the coin or bar on the yellow surface of the device, and the display shows the measured conductivity in MS/m, that is, in megasiemens per metre. Behind this is the eddy current principle: an alternating magnetic field induces weak electrical currents in the metal, whose behaviour depends on the conductivity of the material. Every metal and every alloy has a typical value. Fine gold conducts differently from a gold coin containing copper, and silver in turn differently from gold.

If the measured value matches the expected value of the alloy in question, this indicates a genuine piece. The display also shows materials such as brass and tungsten, which play a role in counterfeits.

Counterfeits with a foreign core

Particularly treacherous are bars and coins with a tungsten core wrapped in real gold. Tungsten has almost the same density as gold, so such pieces hardly give themselves away on the scales. In its electrical conductivity, however, tungsten differs significantly from gold. Because the measurement does not only capture the surface but reaches some way into the metal, the measured value for a thin layer of gold over a foreign core deviates from the expected value in many cases. A test that only looks at the surface would find nothing but real gold here.

Who benefits from a testing device of their own

The GoldScreen Sensor is aimed at everyone who not only wants to own their precious metal but also to assess it themselves. Investors who buy coins or bars from private individuals can test a piece before paying. Collectors check their new acquisitions, and heirs get a first overview of an estate. Anyone who reviews their own holdings from time to time also gains a clear view of every piece with a testing device of their own.

Limits and useful additions

No single testing method detects every conceivable counterfeit, and the GoldScreen Sensor does not replace care either. Conductivity is most meaningful together with the weight, diameter and thickness of the piece: if all values match, you have a solid basis for your assessment. With very small, very thin or irregularly shaped pieces, the measurement reaches its limits. Older coins may also show deviating values due to impurities from the time they were made, without being counterfeit; here, further testing methods such as a density test can help.

Reasons for the GoldScreen Sensor

1. More certainty with every piece whose origin you do not know in full.
2. The measurement reaches below the surface and can therefore also uncover a layer of gold over a foreign core.
3. Your coins and bars remain intact: no scratching, no filing, no acid.
4. The scale on the display makes it easier to classify the measured value.
5. You test at home and in peace, without having to hand over a piece.

Genuine precious metal has nothing to hide. A measured value makes visible what the eye cannot see.

Get more certainty for your precious metal holdings: with the GoldScreen Sensor from Goldanalytix at Kettner Edelmetalle.