专利名称：METHOD AND APPARATUS FOR
EVALUATING LENGTH OF DEFECT IN EDDYCURRENT TESTING
发明人：Akira NISHIMIZU,Yoshio Nonaka,Isao
Yoshida,Motoyuki Nakamura,AkihiroTaki,Masahiro Koike
申请号：US11771436申请日：20070629
公开号：US20080004817A1公开日：20080103
专利附图：
摘要：The surface length of a metal subject to be inspected is evaluated by detectingan eddy current without using a combination of a scale and visual or liquid penetrantinspection. An exciting coil and a detecting coil are scanned above the subject in a lengthdirection. An eddy current detector measures an output voltage corresponding toscanning positions based on an output from the detecting coil. Based on an outputvoltage distribution curve indicating a distribution of output voltages corresponding tothe scanning positions, position information is extracted corresponding to values whichare within a differential voltage range and lower by 12 dB than a maximum value of theoutput voltages on the left and right sides of the distribution. A distance between thepositions included in the extracted information is calculated to evaluate the length of aslit which is a defect present on the subject surface.
申请人：Akira NISHIMIZU,Yoshio Nonaka,Isao Yoshida,Motoyuki Nakamura,AkihiroTaki,Masahiro Koike
地址：Tokai JP,Hitachi JP,Hitachi JP,Hitachi JP,Hitachi JP,Hitachi JP
国籍：JP,JP,JP,JP,JP,JP
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