increase sensitivity of metal detector
Detector sensitivity is not constant , it depends on the diameter of the coil , when operating in a mode discrimination sensitivity decreases by several tens of percent . However, the sensitivity is influenced by other factors .
Do not trust advertising ! If the manufacturer or the seller claim that using their device can detect a coin at a depth of 30 cm , ask to clarify – on the surface or in the ground was the reference specimen ( and what kind of coin in question – a penny or silver ) ?
Often used as a metal detector parameters are specified tests in air. Objects are detected in the earth (depending on depth ) 10-30% less efficient. The most important factor affecting the sensitivity of the detector , are dimensions of the object.
To attract buyers manufacturers often specify examples of the sensitivity of its instruments. In particular, we can read : a coin ( which , after all ? ! ) – 30 cm, bronze figure of 40 cm ( what a mass and surface area ? !) – 80 cm, 25x25x50 cm box filled with gold ornaments ( this is is interesting! ) – 1.5 m Such examples are not very reliable. In fact , the detection of an object depends on its weight , shape and surface area. Referred to in the advertisement is the same coin can be registered on the very depth of 30 cm only when it is in the ground obverse or reverse parallel to the plane of the coil . If it is perpendicular to the surface, then we have it, is not likely to find . The conclusion : the greater the surface area parallel to the plane of the coil , the easier it is to find a subject .
Lightweight object that is parallel to the plane of the coil is its greatest , it may be easier to detect than more massive , but failed to lying . A huge impact on the sensitivity of the metal by the nature of the soil in which we are trying to find something .
The sensitivity of the device depending on the ground may be reduced by half. First of all, it is determined by the degree of mineralization. The most permeable loose black mold . A little worse behaved clay. The weakest results are recorded on sandy and rocky soils . Often, different types of soil are arranged in layers or mixed together.
Affects the sensitivity of the soil moisture. Water – it is an electrolyte. Currents passing through it interfere with the metal detector . What wetter the soil, the worse for us . Best results can be expected during periods of prolonged drought. Unfortunately, it’s time to dig into the hardest. Often on the parched soil, especially clay , instead of digging tools required scrap .
Fortunately for us , the older the subject, the easier it is to detect. Corrosion leads to the formation of the oxide layer around the object , and other chemical compounds. Objects not only rust , but also connect the salt from the water table. This leads to a marked increase in their volume, which simplifies detection .
All of these factors – the size of the plates, tapered tip of the electromagnetic field generated by the metal detector , the size and mass of the object, its location relative to the antenna , the type and soil moisture , corrosion of objects of the search – lead to surprising discoveries in areas in which we have passed many times before.