公开(公告)号：US4647856A

公开(公告)日：1987-03-03

申请号：US476877

申请日：1983-03-22

Applicant: Mikhail A. Melgui ,  Valery B. Kratirov ,  Anatoly I. Filippov ,  Viktor V. Deinekin

Inventor： Mikhail A. Melgui ,  Valery B. Kratirov ,  Anatoly I. Filippov ,  Viktor V. Deinekin

IPC: G01R33/12 ,  G01N27/72 ,  G01N27/80

CPC classification number: G01N27/80 ,  G01N27/72

Abstract: A method comprises repeatedly magnetizing a test article by a pulsed axially symmetric magnetic field normal to the surface of the test article, and reading the gradient of a residual field. Magnetizing the article is effected by two trains of pulses in two steps: first until a first instant of discontinuance in the growth of the gradient of a remanent magnetic field and then until a second instant of discontinuance, the pulse amplitude of the second pulse train being lower than a maximum amplitude of the second pulse train.An apparatus to carry out the proposed method comprises a pulse shaper 1 for forming pulses of an axially symmetric magnetic field and a measuring circuit for measuring the gradient of a remanent field normal component. According to the invention said apparatus is further provided with a working storage 4, a comparison circuit 5 and a pulse amplitude measuring device 2 for measuring pulse amplitude at the output of the pulse shaper 1. The amplitude measuring device 2 has its inputs connected to the outputs of the comparison circuit 5 and the pulse shaper 1. The inputs of the working storage 4 and the comparison circuit 2 are connected to the output of the gradient measuring circuit 3. The other input of the comparison circuit 5 is connected to the output of the working storage 4. The pulse shaper 1 includes a storage capacitor, charging and discharging circuits of said capacitor, an inhibit circuit and a comparison circuit, a pulse counter, a decoder and a code-to-analog converter electrically connected to one another.

Abstract translation: PCT No.PCT / SU81 / 00063 Sec。 371日期1983年3月22日 102（e）1983年3月22日PCT PCT。1981年7月28日PCT公布。 公开号WO83 / 00560 日期：1983年2月17日。一种方法包括通过垂直于测试物品表面的脉冲轴对称磁场和读取残余场的梯度来重复地使测试物体磁化。 物品的磁化是通过两列脉冲进行两个步骤：首先直到第一个停止生长剩余磁场梯度的瞬间，然后直到第二个停止时刻，第二个脉冲串的脉冲幅度为 低于第二脉冲串的最大振幅。 用于实现所提出的方法的装置包括用于形成轴对称磁场的脉冲的脉冲整形器1和用于测量剩磁场法线分量的梯度的测量电路。 根据本发明，所述装置还设置有工作存储器4，比较电路5和用于测量脉冲整形器1的输出处的脉冲幅度的脉冲幅度测量装置2.振幅测量装置2的输入连接到 比较电路5和脉冲整形器1的输出。工作存储器4和比较电路2的输入连接到梯度测量电路3的输出。比较电路5的另一个输入端连接到 脉冲整形器1包括存储电容器，所述电容器的充电和放电电路，禁止电路和比较电路，脉冲计数器，解码器和彼此电连接的代码到模拟转换器。