| 摘要 |
A magnetic field is generated by means of an emitter (10) situated at the vicinity of the surface (S) of a product to be tested and a receiver (11) distinct from the emitter is arranged, with respect to the emitter, on one hand so as to be aligned with the emitter in a direction corresponding to the general orientation of the defects to be detected at the surface of the product and, on the other hand so as not to be substantially influenced by Foucault currents generated by the emitter when the product surface is free of defects so that a significant signal is received by the receiver only in the case of deviation of the Foucault currents to its direction due to a discontinuity (D) and the surface of the product. The invention is applied to the detection of surface defects of metallurgical semiproducts, particularly continuously cast iron and steel semiproducts. |
