| 摘要 |
<p>PCT No. PCT/NO87/00014 Sec. 371 Date Oct. 15, 1987 Sec. 102(e) Date Oct. 15, 1987 PCT Filed Feb. 16, 1987 PCT Pub. No. WO87/05112 PCT Pub. Date Aug. 27, 1987.A method and apparatus for generating and detecting magnetization responses from ferromagnetic, ferrimagnetic, paramagnetic, or diamagnetic materials comprises a means for generating an alternating magnetic field. The cycle of the alternating magnetic field includes a first magnetization pulse and a second demagnetization pulse, the energy content of the magnetization pulse and the demagnetization pulse being approximately equal, the time duration of the magnetization pulse being substantially longer than the time period of the magnetization pulse, the demagnetization pulse having a higher magnetic field strength than the magnetization pulse magnetic field strength. The effect of the alternating magnetic field on the material to be tested is measured by magnetic field detectors. The field detectors generate electrical signals which are fed to an oscilloscope, a comparator, or a computer for analysis. Characteristics of the material to be tested which are measured by the device include rotation of the magnetic domains, alignment of magnetic domains, alignment of magnetic moments, the Barkhausen effect, coercive force, remanence, material structure, stress fields, and defects.</p> |
