Conductivity Measurement for Non-Magnetic Materials Using Eddy Current Method with a Novel Simplified Model

Area of Science:

• Materials Science
• Electrical Engineering
• Non-Destructive Testing

Background:

• Conventional eddy current testing (ECT) is hindered by material thickness variations and complex analytical models.
• Arbitrary excitation frequency selection and intricate inverse calculations limit practical ECT applications.
• Need for a simplified, accurate, and efficient method for non-destructive conductivity measurement.

Purpose of the Study:

• To propose a simplified analytical model for measuring the conductivity of non-ferromagnetic materials using ECT.
• To develop a direct conductivity calculation method bypassing complex inversion processes.
• To establish a frequency selection criterion using finite element method (FEM) analysis for optimized measurements.

Main Methods:

• Simplified the classical Dodd-Deeds analytical model for high-frequency electromagnetic conditions.
• Developed a direct relationship between coil impedance phase and material conductivity.
• Integrated finite element method (FEM) analysis for frequency selection and measurement method development.

Main Results:

• The proposed method accurately measures conductivity in non-ferromagnetic materials from 0.5-58.5 MS/m.
• Achieved low absolute error (<1.05 MS/m) and relative error (<1.83%).
• Eliminated the need for complex inversion calculations and multiple calibrations.

Conclusions:

• The simplified analytical model provides a direct and accurate method for conductivity measurement.
• The technique offers a robust alternative to conventional ECT, overcoming its limitations.
• Paves the way for developing advanced online inspection systems and portable instrumentation for material characterization.