SONDA DE CORRENTE PARASITARIA FERROMAGNETICA TENDO MAGNETIZACAO EXCENTRICA

摘要

Eddy current probes for ferromagnetic tubes of relatively small diameters are disclosed. A probe housing is made of non-ferromagnetic material and shaped to be introduced into the tube for inspection. The probe housing includes at least two eddy current measuring assemblies either of these assemblies includes magnetic field generators for producing a maximum magnetization at a predetermined area of the tube and a minimum magnetization at a diametrically opposite area of the tube. At least one eddy current measuring coil is associated with each magnetic field generator to measure the eddy current generated in the tube and which has a relatively high sensitivity to an anomaly at the maximum magnetization area. Further the current measuring assemblies are spaced apart axially within the housing and are rotated about its central axis by a predetermined angle so that each assembly differs in sensitivity to an anomaly depending upon their location within the housing.