| 摘要 |
PURPOSE:To accurately measure the change of magnetostriction due to temp. change through the measurement temp. change by the measurement of constant of small magnetostriction, by detecting the brightness change of interference fringe based on a change amount caused by magnetostriction by a photo-voltage conversion apparatus such as a solar cell or the like as voltage variation. CONSTITUTION:Interference fringe generated when laser beam is reflected on the upper surface of a lower quartz interference plate S2 and the under surface of an upper quartz interference plate S1 is subjected to electric conversion by using a solar cell S.C. to be detected by a voltmeter V.M. When a magnetic field is applied by solenoid 3 or heating is applied, interference fringe obtained from a specimen 1 prior to applying a magnetic field and heating is displaced from interference fringe from the specimen 1 undergoing the change caused by magnetostriction and a temp. and the voltage difference of both of them is based on the extension and contraction of the specimen 1 caused by magnetostriction and the temp. When the variation amount DELTAl of the specimen 1 is smaller than the 1/4 wavelength of before and after the magnetic field is applied and the max. value Vmax and the min. value Vmin measured by heating the specimen 1 are substituted for a formula to obtain constant of magnetostriction. |
