build your own gold detector

Here it is worth considering the main difference between the metal detector for gold. This metal is not magnetizable. So it doesn't have its own magnetic field. If it were, the detector would determine the difference between the frequency of the transmitted field and the detected one. Thus, the device can with great accuracy screen out "ferrous" metals from precious ones.

Characteristics of sensitivity and selectivity. The first characteristic greatly affects the search result. Gold is not always in the form of jewelry or any objects. Very often this metal is in the ground in the form of small particles or stones. To search for such elements, the device must operate in the range from 15 kHz and above. The selectivity of the device is also very important. This parameter allows you to weed out all materials that have the property of magnetization. Also, the device must determine copper, aluminum, bronze by the characteristics of electrical conductivity in a humid environment. If the nugget is in soil with a large amount of iron ore, it is the selectivity function that will help determine the change in the magnitude of the MP oscillations.