Can I test all coins and bars with the GoldScreenSensor?

In general, you can test all bars and coins with the GoldScreenSensor. However, there are cases that limit the accuracy of the measurement.

For thicker test objects (50 to 100 grams or more, depending on the geometry), we recommend using the BarScreenSensor  in addition to the GoldScreenSensor to account for thickly rolled gold plating.

Coins smaller than 1/4 ounce have a slightly different conductivity value than the material should have, since the measurement area is not fully covered.

Old coins (pre-1945) may also sometimes contain impurities. For example, 986 ducats consist of only 986/1000 parts gold; ideally, the rest is copper. However, since the refining process had not yet been sufficiently perfected at that time, these 14/1000 parts may also consist of other metals that distort the conductivity value.

Furthermore, the GoldScreenSensor cannot penetrate particularly thick blisters and capsules (>3 mm), such as NGC packaging.