The present invention provides an improved magnetometer to efficiently evaluate subsurface characteristics of conductive material without destroying the material. A white noise generator drives an induction coil to induce measurable currents in a work piece at multiple frequencies. Multiple super conducting quantum interference devices (SQUIDs) measure the magnetic filed created by the currents. The SQUIDs are housed in a liquid nitrogen Dewar. The SQUIDs are aligned along a Josephson junction and are manufactured on a single substrate. A mover moves the work piece adjacent the super conducting quantum interference devices. A computer analyzes the measured data.
 This invention was made with Government support under Contract Number W-7405-ENG-36 awarded by the United States Department of Energy to The Regents of the University of California. The Government has certain rights in the invention.