Types settings metal detectors on the ground
When searching finds soil will always affect the input signal of the receiver coil . It is expressed in 2 “harmful” effects – weakening of a probing signal and the detector response from the target signal from the ground (noise) .
Clay conductivity properties may be due to the presence of salts dissolved in the subsoil water. Some soil types , especially those with a high content of iron and salt effect on the input signal is strong enough – the signal received from the soil with a metal detector can be 1,000 times stronger than the signal from the metal object buried in the ground to a sufficient depth . Signal from the ground as much changes when lifting and lowering of the ring – the passage of the embankment or over a pit . Small changes in the characteristics of the soil with stones can lead to short change the input signal. These changes may cause ” target -like ” signals in the device. They may confuse the operator , as determined by a sound like metal objects . Examples of heavy soil : Red clay , the transition between dry and wet sea sand , with small patches of soil containing iron compounds or rocks ( iron ore , pyrite, magnesite ) .
Fortunately, the phase shift of the received signal from the soil remains fairly constant within a certain area of the Earth’s surface , and the phase change of the signal caused by the presence of metallic target – small and short . This metal detectors required digital circuitry to detect and filter out these short-term changes , on a background of intense but constant signal from the ground ( noise).
Metal Clay have a means to compensate and eliminate “harmful” effects of land – setting function on the ground (Ground Balance). To remove spurious signals is usually necessary to adjust the sensitivity downward. Parameter is directly related to the sensitivity – detection depth . When searching always desirable to detect finds deep underground. Good detuning from the ground also makes it possible to determine with great accuracy the location of the object, and to evaluate its depth .
Modern metal detectors, and depending on the configuration and signal processing techniques , the function of compensating the effect of treatment can be classified into 3 types :
1. Automatic ( pre-installed) Balance soil.
2 . Automatic with manual ground balance adjustment .
3 . Automatically tracking balance adjustment soil.
Areas marked in a different tone in the figure show the extent of mineralization of soil. Over sloping – surveyed layer of earth beneath the volume that is not examined properly – white.
searches for an initial installation of automatic ground balance when the metal detector , without manual intervention on the ground. Often this setting is called automatically preloaded (Automatic Ground Balance). Produce this detuning , until the start of the scan . It is necessary that the operator lowered coil unit close to the ground and moved its “top – down” by adjusting the sensitivity of the device until the effect of the soil in the form of beeps will not disappear . Usually in two stages: the first – with a raised , and the second – with lowered to the ground coil. When the motion of the operator in the search targets , possible changes in the properties of the mineral soil under the coil lead to the fact that the phase of the signal from the ground ” stepwise ” and is changed scores useful target signal . This “noise” reduces the effective depth of search in this place.
Dedicated to figure a different tone areas indicate zones of varying degrees of soil salinity . Over sloping – surveyed layer of earth beneath the volume that is not examined properly – white.
as an experienced professional can reduce the sensitivity and avoid missing the target by manually adjusting the balance of the soil. This is possible with a manual ground balance function in the detector , without turning off the device . (Manual Ground Balance). This type of soil is the detuning of the most accurate, enabling them to achieve the maximum possible depth of detection in a particular place . Manual tuning out from the land looks like this: the operator raises and lowers the metal detector search coil , turning the knob and the disappearance of achieving sound or visual indicator readings . Although this method is effective, it may seem tedious , but for some users , and quite complex . It is not productive to search large areas , because required to visually identify changes in the composition of the soil , and frequent ground balance setting is time-consuming .
Dedicated to figure a different tone areas indicate zones of varying degrees of soil salinity . Over the line – surveyed layer of earth beneath the volume , which is not examined properly and white.
automatic tracking system is shown on the bottom of the metal detector settings (Automatic Tracking Ground Balance), which automatically adjusts the unit to changes in the soil and the maximum sensitivity of the detector to the entire depth of detection purposes without a permit and false positives. These are the “smart” but also expensive devices that will carry constantly adjusts so that you do not even notice it during the transition from one to another type of soil . Devices with this feature allows you to configure – time to spend the rest of the day searching without additional tweaks . The truth is sometimes very brief and frequent changes in the input signal received at a high scan rate of soil or rocks containing iron compounds , can cause disruption in the operation of the electronic filter, and as a consequence of false positives.