| 摘要 |
PCT No. PCT/GB93/02083 Sec. 371 Date May 19, 1995 Sec. 102(e) Date May 19, 1995 PCT Filed Oct. 7, 1993 PCT Pub. No. WO94/08249 PCT Pub. Date Apr. 14, 1994High-energy permanent magnetic materials are characterized by exposing the material to sequential pulsed fields of respectively different rates of change of magnetic field strength, sensing the total magnetic field strength, sensing the total magnetic field generated in the sample by the respective pulses including eddy currents induced therein, and eliminating eddy current components from the said fields, whereby the net magnetic fields relate to the magnetic characteristics of the sample. Preferably the pulsed field is capacitor-generated via a solenoid and the rate of change of the magnetic field strength is produced by holding the waveform constant and altering the pulse duration, for example by providing taps on the solenoid together with an inductor and a balancing resistor, to enable the ratio of resistance to inductance to be maintained substantially constant across the range of taps utilized.
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