Metal detector based on high-Tc RF SQUID

Metal detector has many applications in food industries, wood board plants, safety security and landmine searching. Using eddy-current method, we constructed a metal detector based on high-T-c RF SQUID, and aluminum particle as small as 10 mg could be easily detected. A small ferrous particle in food wrapped by aluminum film could also be detected when a lower excitation frequency of 30 Hz was used. We also proved mobile RF SQUID magnetometer was possible and we will use it to detect metal or concrete structures buried in underground. (C) 2002 Elsevier Science B.V. All rights reserved.