| 摘要 |
PURPOSE:To obtain a meter having high general-purpose applications, by turning and moving a U-shaped moving body with respect to a magnetostrictive wire, which is formed in a circular shape and wound by a plurality of turns, and providing a signal generating part and detecting part at one end of the magnetostrictive wire and the moving body. CONSTITUTION:A U-shaped moving body 60 is provided so as to hold a magnetostrictive wire 40, which is wound by a plurality of turns in a circular shape. The moving body 60 is turned and moved relatively with respect to the magnetostrictive wire. An ultrasonic-wave signal generating part 90 and detecting part 100 are provided at one end of the magnetostrictive wire 40 and the moving body, respectively. When a driving coil 91 is energized, local change in magnetic field occurs at an end part 41 of the magnetostriction line 40. The change is converted into longitudinal elastic waves by the magnetostriction effect, and the waves move to the detecting part 100. Meanwhile, in the detecting part 100, magnetic flux generated in a permanent magnet 103 forms a closed magnetic path. When a magnetostriction signals enters said magnetic path through the magnetostrictive wire 40, the permeance of the magnetic path is changed by the reverse magnetostriction effect. As a result, a pulse voltage, which has a delay time corresponding to the displaced position of the detecting part, is generated in a detecting coil 104. |
