Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

Using eddy-currents to detect flaws buried deeply in a conducting material has always been a difficult problem. This is due in part to the fact that deep penetration requires low frequencies so that the skin depth is large enough for the eddy-currents to penetrate into the material the depth of the flaw. Also, low frequency eddy-current methods are beset with difficulties in probe design. In order to achieve the large inductance needed to operate at frequencies below 1 kHz, a large number of turns is needed, adding to the resistance of the coil and reducing the energy available to couple into the test piece. One solution is to use pulsed eddy-current methods, which operate efficiently and effectively with low inductance coils.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17A

Chapter

Chapter 1: Standard Techniques

Section

Eddy Currents

Pages

291-298

DOI

10.1007/978-1-4615-5339-7_37

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Low Frequency, Pulsed Eddy Currents for Deep Penetration

La Jolla, CA

Using eddy-currents to detect flaws buried deeply in a conducting material has always been a difficult problem. This is due in part to the fact that deep penetration requires low frequencies so that the skin depth is large enough for the eddy-currents to penetrate into the material the depth of the flaw. Also, low frequency eddy-current methods are beset with difficulties in probe design. In order to achieve the large inductance needed to operate at frequencies below 1 kHz, a large number of turns is needed, adding to the resistance of the coil and reducing the energy available to couple into the test piece. One solution is to use pulsed eddy-current methods, which operate efficiently and effectively with low inductance coils.