An investigation for the design of the metal barcode label with patterns read by the eddy current testing

In this paper, the design of the metal barcode label consisting of patterns (PMBL) was investigated, where each pattern consisted of multiple negligible opening slots and stood for a m -ary digit. The 2-dimentional dyadic Green function integration method was generalized to calculate the impedance change of the exciting coil caused by a PMBL. The impedance change was a global variable, which came from not only the pattern beneath the exciting coil, but also its neighbor patterns. It was named as the inter-pattern interference (IPI). The IPI was investigated. According to the IPI, the interval between patterns, the interval between slots and the maximum pattern width were given. These predictions had been proven quite reliable by simulations. Some suggestions on designing a PMBL were given.