Metal Detectors
In the 20 years in the U.S. have developed instruments that detect the tools and finished products that are brought workers from the factories. Instruments called detectors (metal detector literally – Metal Detector). Metal detectors or, in Russian, "Metal detectors" are interested in the military. During the Second World War quickly developed technique of metal detection, and had developed special equipment to search for mines. After the war it was sold cheaply in United States, and many people quickly assessed the possibility of detectors in the search of buried treasures and gold nuggets.
Postwar detectors worked on vacuum tubes, were bulky and consume much energy. Only in mid-60s were created compact, stable and sensitive instruments that can distinguish between metal and allowed to rebuild on the influence of the environment. Types There are several types of metal detectors schemes that are used in metal detectors, including: beat frequency oscillator, the transmission-reception, low-frequency and pulsed-induction scheme. Detectors made on the basis of the oscillator circuit frequency beats (GCHB) no longer produced, although widely used today. They have proven themselves poorly in salt and iron mineralized soil. But behave satisfactorily in areas with a minimum salinity of land (when observed the presence of natural minerals, particularly iron and salt, affecting the detector signal). GCHB detectors provide a little depth of search coil and a narrower dynamic range than other types of detectors.
Automatic ground balancing the low-frequency metal detector makes it a good and acceptable choice for searchers. These detectors are easy to use. The operator is unnecessary to manually configure more detector to eliminate the effects of mineralization, since the device has a special feature that does this automatically. Automatically rebuilt from the ground-frequency metal detectors are called detectors, "movement" or dynamic. The coil unit must be in constant motion to determine the location of metallic objects. If the user stops moving coil over the target, reflecting the signal, the sound of the instrument gradually decays. However, very little movement causes the majority of devices to work. The operator can almost stop moving coil instrument for the precise targeting of finding subject. But some of these metal detectors have a feature electronic targeting regime that allows the operator to switch between motion and static mode (search coil nepodvizhka). Suschestvuyuet different number of spetsializrovannyh detectors when necessary to search under water, or other extreme environmental conditions that exist. Underwater metal detectors are designed with full immersion of the whole instrument together with the control panel. The maximum depth from which they can dive varies depending on the model and can reach about 60 meters. Divers often use pulse induction metal detector for underwater exploration, although the low-frequency detector with automatic ground detuning also works well in these conditions. Pulse induction metal detector is known for his deep abilities. These detectors ignore the black metal and salt water, which may affect the sensitivity of other types of muscular dystrophy. Until recently, pulse induction metal detectors require more power than the battery-frequency devices with automatic detuning of the soil. As a result, these detectors have a lot of weight and less battery power than other systems. New developments, however, increased battery life and lower the unit total weight. The principle of operation and the device most commonly at the moment the principle of metal: Ultra Low Frequency – (VLF) and executed by the scheme, the transmitter premnik – (TR). Thematic Forum Index all issues related to metal detector search of those. support a review of the models from leading manufacturers.