Method for inspecting a metal concrete-prestressing element of a pipeline, and inspection device

A method for inspecting a metallic concrete tensioning element, the method comprising the steps of:

• generating, with at least one first excitation unit of an inspection device, a first alternating magnetic field;
• and
• generating, with at least one second excitation unit of the inspection device, a second alternating magnetic field, wherein the second excitation unit is spaced apart from the first excitation unit,
• wherein the first and second magnetic fields having opposite directions, and
• wherein during a movement of the inspection device along the concrete tensioning element at least at one position between the first and the second excitation units via at least one magnetic field sensor of the inspection device, measurement data are recorded based on the resulting magnetic field, which measurement data are evaluated with regard to the magnitude and/or phase of the resulting magnetic field.