| 摘要 |
<p>The present invention provides an improved magnetometer (10) to efficiently evaluate subsurface characteristics of conductive material without destroying the material. A white noise generator drives an induction coil (14) to induce measurable currents in a work piece at multiple frequencies. Multiple super conducting quantum interference devices 'SQUIDs' (16) measure the magnetic filed created by the currents. The SQUIDs are housed in a liquid nitrogen Dewar (12). The SQUIDs are aligned along a Josephson junction and are manufactured on a single substrate (34). A mover moves the work piece (18) adjacent the super conducting quantum interference devices. A computer (26) analyzes the measured data.</p> |
