METHOD AND DEVICE FOR TESTING PIPES IN A NON-DESTRUCTIVE MANNER

摘要

The invention relates to a method for testing pipes (1) in a non-destructive manner with the aid of a dispersion flow, said pipes being made of ferromagnetic steel. According to the invention, the pipe which is displaced in the longitudinal direction and, optionally, rotated is magnetised by a continuous field and the produced magnetic flow is transmitted in a contactless manner to the pipe. Projections (4, 4') which are located in the areas close to the surface of the external and internal surfaces of the pipes provoke magnetic dispersion flows which exit the surface of the pipe and can be detected by sensors (2, 2'). Ampltitudes, preferably the horizontal field components of the magnetic flow, which can alter in the vertical direction are detected at a distance close to the surface of the external surface of the pipe and at a distance therefrom. The detected signals are determined in relation to each other. The invention also relates to the device for carrying out said method.