Location

Snowmass Village, CO

Start Date

1-1-1995 12:00 AM

Description

The calculation of the impedance of a right-cylindrical air-core coil placed next to a flat plate of a uniform polycrystalline metal alloy is a canonical problem in quantitative eddy-current inspection. Cheng [1] and Dodd and Deeds [2] proposed a widely-used solution for a coil next to a semi-infinite half-space of metal, which agrees quantitatively with impedance measurements made for a wide variety of thick but nonmagnetic metal plates. Said plates were assumed to have a uniform and frequency-independent conductivity, σ. The same authors proposed a similar solution for ferromagnetic metals (such as iron, steel and nickel), characterized by both a uniform σ and a nontrivial uniform permeability ¼.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

14A

Chapter

Chapter 1: Standard Techniques

Section

Eddy Currents

Pages

315-322

DOI

10.1007/978-1-4615-1987-4_36

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Magnetic Permeability and Eddy-Current Measurements

Snowmass Village, CO

The calculation of the impedance of a right-cylindrical air-core coil placed next to a flat plate of a uniform polycrystalline metal alloy is a canonical problem in quantitative eddy-current inspection. Cheng [1] and Dodd and Deeds [2] proposed a widely-used solution for a coil next to a semi-infinite half-space of metal, which agrees quantitatively with impedance measurements made for a wide variety of thick but nonmagnetic metal plates. Said plates were assumed to have a uniform and frequency-independent conductivity, σ. The same authors proposed a similar solution for ferromagnetic metals (such as iron, steel and nickel), characterized by both a uniform σ and a nontrivial uniform permeability ¼.