Probe characterisation and simulation of conductivity

摘要

The sensitivity to defects and other parameters of control can be improved by the optimal choice of the probe. It appears, after study of the different types of probes (ferritic, sweet steel, insulator) with different geometry (dish, conical...), necessary to underline that the success of a research of feasibility depends largely on the good definition of measure collectors, such sort that they are adapted to the considered problem. The Eddy Current NDT simulation can be resolve the material characterization problems. The principal rules of simulation is to explain the physical phenomena between the power source and the material testing. The second approach is to determinate material conductivity simulation by using the diagram impedance and a different variables parameters (Frequency, factor K...). The testing probe realization by eddy currents was satisfactory at the sight of control and testing results of coating samples. The fundamental parameters to keep in mind for a probe construction are to diminish the reluctance of the measure circuit. To allow an exchange between the probe and the material to be tested optimal energy. A magnetic probe shell be realized in a material of a high magnetic permeability and a low electric conductivity The results obtained by the probe whose nucleus and coil are conic allows to conclude that Sensibility increases with this geometry. The resulting field at the contact point with the material to be tested can be as simile to a material point. The influence of the lateral field is considerably minimized. The results obtained by simulation on the material are conform with practice measure. The simulation application is valuable only for non magnetic material.