发明名称 |
METHOD AND APPARATUS FOR EVALUATING LENGTH OF DEFECT IN EDDY CURRENT TESTING |
摘要 |
The surface length of a metal subject to be inspected is evaluated by detecting an eddy current without using a combination of a scale and visual or liquid penetrant inspection. An exciting coil and a detecting coil are scanned above the subject in a length direction. An eddy current detector measures an output voltage corresponding to scanning positions based on an output from the detecting coil. Based on an output voltage distribution curve indicating a distribution of output voltages corresponding to the scanning positions, position information is extracted corresponding to values which are within a differential voltage range and lower by 12 dB than a maximum value of the output voltages on the left and right sides of the distribution. A distance between the positions included in the extracted information is calculated to evaluate the length of a slit which is a defect present on the subject surface.
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申请公布号 |
US2011148404(A1) |
申请公布日期 |
2011.06.23 |
申请号 |
US201113028500 |
申请日期 |
2011.02.16 |
申请人 |
NISHIMIZU AKIRA;NONAKA YOSHIO;YOSHIDA ISAO;NAKAMURA MOTOYUKI;TAKI AKIHIRO;KOIKE MASAHIRO |
发明人 |
NISHIMIZU AKIRA;NONAKA YOSHIO;YOSHIDA ISAO;NAKAMURA MOTOYUKI;TAKI AKIHIRO;KOIKE MASAHIRO |
分类号 |
G01R33/12;G01B7/00;G01B7/34;G01N27/90 |
主分类号 |
G01R33/12 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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