The change of permeability test

Four terminals respectively, low current, low voltage, high current and high potential. The lower part of the terminal connected to the side of the test object, connected to the side of the test object. The other. Soft magnetic alloy before testing inductors are conducted on the LCR table frequency of short circuit and open circuit calibration will introduce how to affect magnetic permeability. Materials. That's interesting, because in the converter switching frequency and working frequency is suitable for different applications of a possible change in kHz between MHz frequency, these may affect the material. Set up using the LCR meter Agilent 4980 a, frequency from 10 kHz - Sweep to 2 MHz. This instrument has four terminals to configuration, can reduce the high temperature of the influence of stray inductance frequency. 。 For short calibration, a shortened board provided by the manufacturer to connect to the four terminals. There will be 201 values sweep, this is the larger value of the instrument. In the micro area or ma area, current and voltage will be sweep. Frequency measurement results has been divided into two categories. Compare each material respectively according to different permeability and inductance changes over applied frequency. In part to compare different materials. The change of the inductance will be expressed as a percentage of initial inductance value. The inductance of the each material deviation from figure 4. 1 you can see, 35 (including iron in the whole testing range is stable. 75 (including iron reaches 200 kHz.