Method and tool for inspecting the condition of the internal surface of pipes

A tool for inspection of the condition of the internal surface of pipes, comprising:

• a Pipe Intervention Gadget (“PIG”) structural body;
• a plurality of eddy current sensors arranged spaced around the circumference of the PIG structural body, wherein each of the plurality of sensors comprises a pair of coils having a geometric axis of winding parallel to an inspection direction, along the direction of travel of the PIG, of the internal surface of the pipe, wherein each coil of the pair is differentially connected, and wherein only one face in contact with the internal surface of the pipe of each of the plurality of sensors, including the respective coils, has the same radius of curvature as that of the internal surface of said pipe;
• and
• a substantially cylindrical pressure vessel mounted in a central housing of the PIG structural body, wherein the pressure vessel tightly houses a set of electronics, wherein the set of electronics includes at least a plurality of Data Acquisition (“DAQ”) electronic boards connected, respectively, to each of the plurality of sensors, an electronic Data Logger comprising at least one internal memory, a transmitter, an angular positioning sensor, and a battery for powering said electronic components.