Patent ID: 8089273

Claim:
A pipeline inspection method comprising: identifying a pipeline defining a circumferential direction and an axial direction and containing an in-line inspection tool comprising a first end, a second end opposite the first end, and a primary sensor section positioned between the first and second ends, the primary sensor section comprising at least one magnet and at least one sensor, the at least one magnet producing a first magnetic field having an orientation, the orientation being directed obliquely with respect to each of the circumferential and axial directions and pointed more toward the first end than toward the second end; producing relative motion between the at least one magnet and the pipeline, the relative motion comprising substantially exclusively translation in the axial direction of the at least one magnet with respect to the pipeline; generating, by the in-line inspection tool during the producing, one or more oblique magnetic fields each having the orientation, the one or more oblique magnetic fields comprising the first magnetic field and all other magnetic fields that emanate from the in-line inspection tool and are oriented obliquely with respect to each of the circumferential and axial directions; and collecting, by the at least one sensor during the generating, data characterizing one or more physical characteristics of the pipeline.