| 摘要 |
PURPOSE:To make it possible to accurately compensate a temp., by a method wherein ultrasonic waves are applied to a displacement measuring object and the phase of the electric signal of the reflected ultrasonic waves is detected to detect the displacement amount of the measuring object. CONSTITUTION:The interval of the reflecting part of a target 121 and an ultrasonic wave transmitter and a receivers 122, 123 is almost equally set to that of the surface of rotary shaft 10 and an ultrasonic wave transmitter and a receiver 103, 104. A reference wave converted to an electric signal by the ultrasonic wave receiver 123 is passed through an amplifier 124 and shaped in the wave form thereof by a wave form shaping device 106 to be imputted in a phase extractor 107. In the next step, temp. compensation and the correction of the change in the amplitude of a receiving wave are applied to the phase difference signal obtained from the above mentioned both waves to obtain the displacement amount of a measuring object. |
