The dilation invariance principle in eddy-current non-destructive evaluation technique analytical justification

摘要

Dilation invariance principle states that the dilation of electrical and dimensional parameters causes the magnetic flux density to be an invariant, provided, the measurements are made at every equivalent points. It is in use in the field of electromagnetic non-destructive testing. The proposed principle has been verified experimentally. This manuscript aims to develop an analytical proof that the magnetic field is an invariant under the dilation of dimensional and electrical parameters. An axially symmetric model for the case of the probe over the plate has been considered in the manuscript. The surface plot of the magnetic flux density has been obtained by using prevalent numerical integration technique.