A Method for Imaging Steel Bars Behind a Ferrous Steel Boundary

摘要

A system for detecting steel objects behind ferrous steel boundaries is described. It may be used to image steel reinforcing bars in concrete, where a steel sheet exists between the bars and the surface. The sensor comprises a transmitter, receiver and a dummy coil, which cancels cross-talk and enhances the signal from the bars. It is possible to penetrate a 2mm thick sheet at 125 Hz and image 16 mm diameter bars placed underneath.