Magnetic flux leakage probe with radially offset coils for use in nondestructive testing of pipes and tubes

摘要

A magnetic flux detection probe for use in nondestructive testing of tubular products includes first and second flux leakage sensing coils mounted within a probe housing and radially offset with respect to each other to provide improved detection of defect locations and magnitudes. In a preferred embodiment a Hall effect sensing device is provided in the probe to sense variations in wall thickness of a tubular product while the flux leakage coils identify sharp responses of cracks and pits in the wall structure.