Influence of Anisotropy on Eddy Current Conductivity Measurement

Analytical expression, describing the complex introduced voltage of attachable eddy current transducer with concentric excitation and measuring coils placed on the surface of non-magnetic conductive plate with uniaxial electrical conductivity anisotropy, is obtained. On the basis of its numerical analysis is show, that the anisotropy causes additional error of electrical conductivity eddy current measurement. The estimation of this error is carry out. It's significantly smaller when amplitude of introduced voltage is used as informative parameter compared to its phase. Error of phase eddy current gauges is essentially independent of generalized testing parameter and is equal 2.4 - 2.5%.