The fast calculation of the metal barcode label read by the eddy current testing with the dyadic Green function method

In this paper, we reduced the quadratic complexity of estimating the coil impedance change caused by a metal barcode label with the dyadic Green's function method down to a linear one. It was proved to be stable and convergent by simulations. With this reduction, it is convenient to estimate the output of a metal barcode label consisting of tens of bits read by the eddy current testing.