During the 1960s, the primary industrial steel detectors were created, and so they were being widely employed for mineral prospecting along with other industrial needs.?? ???? ??? ??? ??????? ??????? ??? ????? ???????? ?????? ??????? ?? ?????? ??? ?????? ??? ??? ????????? ??? ??????? ? ????? ????? ??? ???? ????? ??? ?????? ???? ??? ??? ??????? ????