| 摘要 |
PURPOSE:To eliminate the need of correcting the coordinate position and to improve the measurement accuracy by using a magnetostriction plate provided with an oscillation source. CONSTITUTION:An AC magnetic field and distorsion are propagated in the direction indicated by an arrow A from an oscillation source 2 provided at one end of a magnetostriction plate 1 to an oscillation absorber 3. When a magnetic sensor 4 is placed on such magnetostriction plate 1, phase of an AC magnetic field at the magnetic sensor 4 is delayed from phase of an AC magnetic field at the oscillation source 2 by a time corresponding to distance/velocity of sound. Thus, a phase difference between both the AC magnetic fields is proportional to the coordinate at which the magnetic sensor 4 is positioned. In such a manner, the phase difference and coordinate position obtained at the magnetic sensor are in a proportional relation with each other, so it becomes possible to eliminate the need of correcting the coordinate position. |
