棒の磁歪振動

I. 縦振動

抄録

Measuring method of magnetostrictive vibration is improved to suit the study of mechanism of magnetization process.
The e. m. f. induced in a flat search coil by the longitudinal vibration of a rod is displayed on a C. R. O.. Introducing a marker on the Lissajous' circle by making use of the intensity-modulation technique, the e. m. f. in vector representation is read directly on the screen. It is proved that the locus of this marker, the “resonance circle”, is equivalent to the motional impedance (or admittance) circle.
To obtain definite values of the resonance frequency and Q^-1 in a certain field independent of exciting procedures, it is necessary to measure them in terms of exciting current or voltage and estimate those values by extrapolating to zero of the current or voltage.
The diameter of the “circle” divided by the current at resonance depends only on the field intensity and considered as a measure of the slope of the magnetostriction vs. field curve.