Most metal detectors (even the most common ones) can detect and find their targets at a depth of 10 to 20 cm. The depth of a mid-range metal detector is up to 30 to 45 cm, and the depth of a professional metal detector can reach up to 20 meters.
The depth depends on factors such as the type of metal detector and the type of object buried in the soil, as well as other factors such as minerals in the soil.
Of course, in this article, we will discuss how deep a metal detector can detect. Of course, there are various contradictory information and unclear explanations about this issue, but here we are trying to reach a unified understanding of this issue.
First, we will explain how the three factors of size, shape and direction affect the depth, and we will also examine different types of metal detectors. We will also describe topics such as frequencies and search coils and loops, and finally we will talk about the effect of earth’s minerals on depth.
Target size
A metal detector detects large targets at a greater depth and vice versa for smaller targets. Larger targets have a larger surface area than smaller targets, and this causes more disturbance in the electromagnetic field produced by the metal detector, and as a result, the metal is identified.
Target shape
The shape of the target is effective for easier detection by the metal detector. Metal detectors detect circular flat objects like coins, rings, or rectangular objects like boxes and trays better because of their surface. It is a bit more difficult to detect narrow and thin objects such as nails or wires in deeper soil.
The composition of the target metal
The type and material of the metal you are looking for affects the depth of the search. You can find highly conductive (electricity) metals (such as silver) at a greater depth than less conductive metals such as gold, aluminum, lead, or stainless steel.
Placement direction
A target that is flat (horizontal) is easier to detect than a vertical target. This is because horizontal flat objects have more surface area to disrupt the EM electromagnetic field from the metal detector transmissions. A vertical target provides less surface area to work on and is therefore more difficult to detect.
