A NEW METHOD FOR FAST TANK FLOOR INSPECTION

This article presents a newly developed rotary scanning technique that combines eddy current and flux leakage test methods to inspect up to 3/8-in. (9.53-mm) flat carbon steel plate. The technique relies on a t est probe that uses both methods to inspect the same location simultan eously. The eddy current method responds primarily to top surface sign als, while the flux leakage method detects conditions on the top and b ottom surfaces. By processing these signals and displaying them in a s imultaneous dual-trace display, a determination can be made as to whet her the signal originated from the top or back side of the floor plate .