???? ??????? ??????? ?? ?? ??? ???? ????? ????? ?? ???????? ???????? ?????? ??????. ????? ?? ???? ?????? ????? ???? ?????? ?? ???? ????? ????? ?? ?????.The most common form of metallic detector is often a hand-held metal detector or coil-based mostly detectors working with oval-shaped disks with constructed-in copper coils. The research coil perfor