New Convenient Formula for Impedance Change Calculation in Non-destructive Testing Problems by Control of Eddy Currents
ABSTRACT. This paper is devoted to the analysis of control characteristics used in problems of non-destructive testing by eddy currents. A new exact analytical formula for the impedance change used in non-destructive testing problems is derived. The derivation is based on the Green’s formula. The new formula for the impedance change has the form of a triple integral of scalar product of two vector potentials: the vector potential in the flaw and the vector potential in the same region in the absence of the flaw over the region containing the flaw. The new obtained formula is equivalent to the formula known in literature, but the new one is more convenient for calculations.
KEYWORDS: eddy currents, impedance change, vector potential
The present paper is a theoretical work dealing with problems of non-destructive testing by control of eddy currents. Non-destructive testing methods are widely used in industry for quality control of products and materials. The term “non-destructive testing” usually refers to inspection methods for testing properties of materials and the quality of products without damaging or impairing the test objects.
One of the non-destructive testing methods used nowadays ...