Patent ID: 8552718

Claim:
A method for the nondestructive testing of pipes of ferromagnetic steel for flaws by means of stray flux, comprising the steps of: magnetizing the pipe with a constant magnetic field having a direction, detecting with probes of a test unit for longitudinal and/or transversal flaw testing, amplitudes or frequencies or both of magnetic stray fluxes caused by a test flaw oriented perpendicular relative to the magnetic field direction; determining a correction factor as a function of the amplitudes or frequencies or both of the magnetic stray fluxes caused by the test flaw; determining an angular orientation of another flaw relative to the magnetic field direction; determining amplitudes or frequencies, or both, of magnetic stray fluxes caused by the other flaw, correcting the amplitudes or frequencies, or both, of the magnetic stray fluxes caused by the other flaw with the determined correction factor, and associating the corrected amplitudes or frequencies, or both of the magnetic stray fluxes with an external or internal flaw based on an amplitude height or a frequency spectrum, or both, via defined flaw thresholds.