That depends on the objects you want to analyse:
For classic investments (coins and bars), the GoldScreenSensor in combination with a caliper and precision scale is usually sufficient (also measures through packaging). For bars from 50 grams and upwards, we recommend the BarScreenSensor, for which the objects have to be unpacked.
For jewellery, the CaratScreenPen is the best way to measure the carat number of gold objects. Another way of testing jewlery is with a combination of the GoldScreenPen, the density scale and a test acid set. The GoldScreenPen can also be used for smaller investment objects up to approx. 1 ounce.
As a tungsten detector, the MagneticScreenScale is a alternative to the GoldScreenSensor for gold objects from about 1/4 ounce up to 250 g. For those who want to focus entirely on gold and do not intend to unpack 100-gram bars, for example, the MagneticScreenScale is a good choice.
For larger or irregularly shaped bars whose dimensions cannot be determined with sufficient accuracy with a caliper, the bar testing set is recommended.