The search depth and target detection accuracy depend on the file size. A universal option for hobbyists and experienced drillers are files 9-12 inches in diameter – this is the most common size and works well in most conditions. Small files, 5 to 9 inches in diameter, are better at “seeing” small objects, but they are unable to look deeply into the soil. Large coils with a diameter of 13-20 inches cover large areas of ground and increase detection depth. The other side of their coin is an inaccurate indication of the location of small objects, making it necessary to drill a larger hole.
Metal detector coils vary not only in size, but also in shape:
Circular – determines the detection site with high accuracy, but is sensitive to highly mineralized soils; Due to the smaller width of the captured area, the time and effort required to scan large areas increases;
Elliptical – elongated coils provide a slightly “stretched” electromagnetic field, which expands the size of the captured area, but somewhat reduces detection accuracy;
Rectangular – typical for deep metal detectors;
Butterfly – structurally, these coils consist of two oval pieces, partially fused and reminiscent of the wings of a butterfly; DoubleD files are produced similarly – the signal in them is in the shape of a cylinder, which makes it possible to scan the area under the file uniformly.
What Size Coil to Use When Metal Detecting & Gold
The size of the coil diameter important
Later, you have chosen the type of coil , it is necessary to pay attention to its size. There are many different sizes of coils . Each is suitable for a particular type of search and for certain conditions of the terrain .
The coil with a large diameter can detect deeper targets , but only for the larger objects. When using large coils lost sensitivity to small targets . The large coil in turn more susceptible to masking.
Masking occurs in a discriminatory regime, when the right goals and unwanted time are under the coil . If both goals are extremely close to each other, then the device will be hard to distinguish between them , there is a risk that the detector can not detect the correct target . Such masking is frequently found in the foundations of old houses , and other trash sites.
The smaller the coil diameter, the more accurate and highly directional field will detect targets . What makes the detector more sensitive to small targets and avoids masking in trashy areas . They are often referred to as ” sniper ” . Unfortunately , small coils typically lose depth compared with larger .
Try to choose a coil in accordance with the place where you want to search. Proper selection of the coil will allow you to find more pleasant discoveries and save time and effort in searching. Most of the search coil is required to ” clean ” the soil , or if you want to achieve greater depth. Small coils help to find small objects , such as gold nuggets or jewelry and excels in trashy areas .