Eddy current testing utilizing cooled normal pickup coil and superconducting quantum interference device picovoltmeter: Comparison between experiment and analysis

Kenichiro Yao, Tong Qing Yang, Daisuke Yamasaki, Kazuya Tazoh, Keiji Enpuku

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Eddy current testing utilizing a cooled normal pickup coil and a high-Tc superconducting quantum interference device (SQUID) picovoltmeter was performed both experimentally and analytically. In the experiment, we successfully detected a small crack on the back surface of a Cu plate by moving the coil in an unshielded environment. First, we developed a method of avoiding the drift of the detected signal that was caused by the variance of lift-off. Next, we clarified the dependences of the detected signal on the excitation frequency and the thickness of the Cu plate. It was shown that an optimum frequency that maximizes the detected signal exists. Because this frequency changed with the thickness of the Cu plate, the frequency dependence could be used to estimate the depth of the crack from the surface of the Cu plate. The experimental results were analyzed taking into account the phase and amplitude of the signal field caused by the crack. Good agreement was obtained between experiment and analysis.

Original languageEnglish
Pages (from-to)4994-4999
Number of pages6
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume45
Issue number6 A
DOIs
Publication statusPublished - Jun 29 2006

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Physics and Astronomy(all)

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