The main principle that metal detectors follow is that electric currents that pass through a loop produces magnetic fields. This is what causes metals to be detected by metal detectors. It is worth knowing that the oscillator is the most basic part of a metal detector. It is the one responsible in creating the alternating current. What happens next is that the magnetic field is then produced when the electricity passes through its own transmittal coil. These are also present in all metal detectors, which is why this happens.A current will then be generated once the metallic objects gets closer to the coil of the metal detector. One can also find another coil that is present in the loop. This is referred to as the receiver coil, and is the one that is responsible in detecting the magnetic field changes. Without this part, there would be no way that metal detectors will work efficiently. The whole mechanism of the metal detector is very reliant on the receiver coil as this part is the one responsible in the detection of the metal material.You can check out this link to know how to Pick this link for the best underwater detectors for metal: http://www.metaldetector.com/learn/buying-guide-articles/marine-salvage-search-recovery/best-metal-detectors-for-underwater-search-recovery
Now, most metal detectors use different kinds of technologies. These are called VLF or the Very Low Frequency, BFO or Beat Frequency Oscillator, and the PI or Pulse Induction technology. Through the passing of time, more and more different kinds of technology are incorporated in metal detectors, making them more efficient and useful at the same time. It is because of these advancements that metal detectors are becoming more popular in different industries today, such as in the food and textile industry, as well as with individual consumers.