Gold, silver and platinum bullion and bars with a flat surface and thickness greater than 1.5mm can be tested. Surface sections to be tested must have at least 8mm diameter without heavy embossing or stamping. This is to ensure a reliable coupling for the probe.
Some 100oz cast (poured) silver bars thicker than 25mm can have strong attenuation properties which can make readings inconsistent. For cast silver 1kg is the recommended maximum bar size for reliable results.
1oz – 100oz cast gold bars
1oz – 100oz minted gold bars
5oz – 1kg cast silver bars
5oz – 100oz minted silver bars
5oz – 100oz minted platinum bars