Pulsed eddy current pipeline inspection system and method

A method of evaluating a pipeline, comprising:

• driving a pulsed eddy current measuring device through the pipeline, the pulsed eddy current measuring device comprising a plurality of stages, each of the plurality of stages adapted to move between a contracted position in which a plurality of pulsed eddy current sensors are disposed around at least a portion of a circumference of each of the plurality of stages with no gap therebetween and an expanded position in which at least one gap exists between sensors disposed on each of the plurality of stages, the plurality of pulsed eddy current sensors being arranged such that the gap between pulsed eddy current sensors disposed around a first one of the plurality of stages in the expanded position is coincident with and longitudinally spaced apart from a location of at least a portion of the plurality of pulsed eddy current sensors around at least a second one of the plurality of stages, such that an entire circumference of the pipeline is covered by the plurality of pulsed eddy current sensors;
• and
• placing the pulsed eddy current measuring device in the contracted position to navigate a constricted portion of the pipeline.