公开(公告)号：US4503393A

公开(公告)日：1985-03-05

申请号：US308749

申请日：1981-10-05

申请人： Mark C. Moyer ,  Clifford W. Petersen ,  Felix N. Kusenberger ,  William D. Perry ,  Floyd A. Balter ,  Cecil M. Teller, II

发明人： Mark C. Moyer ,  Clifford W. Petersen ,  Felix N. Kusenberger ,  William D. Perry ,  Floyd A. Balter ,  Cecil M. Teller, II

IPC分类号： G01N27/82 ,  G01N27/72 ,  G01R33/12

CPC分类号： G01N27/82

摘要： Apparatus for detecting flaws in the threaded end of a ferromagnetic pipe is disclosed. The apparatus comprises means for applying a magnetic force to produce a field generally axially through the threaded end of the pipe, first and second means adjacent successive crests of a thread for sensing a generally radial magnetic field and generating a first and second signal corresponding to the sensed magnetic fields, and means for differentially connecting the signals generated by said first and second sensing means, whereby a differential output signal is produced in response to a flaw between the crests of the thread being inspected. The apparatus also comprises means for helically rotating said sensing means to follow a path corresponding to the threads of the pipe, whereby the first and second signals vary with time.A method for detecting flaws in the threaded end of a ferromagnetic pipe is also disclosed. The method comprises the steps of applying a magnetic force to produce a field generally axially through the threaded end of the pipe, sensing the radial magnetic field adjacent successive crests of a thread of the pipe, generating first and second signals corresponding to the sensed magnetic fields, and differentially connecting the first and second signals.

摘要翻译： 公开了一种用于检测铁磁管的螺纹端部中的缺陷的装置。 该装置包括用于施加磁力以产生大致轴向穿过管道的螺纹端的场的装置，邻近线的相邻波峰的第一和第二装置，用于感测大体上径向的磁场，并产生对应于该第一和第二信号的第一和第二信号 感测磁场，以及用于差分地连接由所述第一和第二感测装置产生的信号的装置，由此响应于所检查的线程的波峰之间的缺陷而产生差分输出信号。 该装置还包括用于螺旋地旋转所述检测装置以跟随对应于管道的螺纹的路径的装置，由此第一和第二信号随时间而变化。 还公开了一种用于检测铁磁管的螺纹端部中的缺陷的方法。 该方法包括以下步骤：施加磁力以产生大致轴向穿过管道的螺纹端的磁场，感测与管道的螺纹的相邻波峰相邻的径向磁场，产生对应于感测磁场的第一和第二信号 ，并差分地连接第一和第二信号。