| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an ultrasonic measuring method and ultrasonic apparatus for measuring the diameter of a workpiece, allowing for easy and accurate sound velocity correction. <P>SOLUTION: The time t<SB POS="POST">1</SB>required for an ultrasonic wave outputted from a sensor 82 to be received by the sensor 82 after reflection on the surface of a cylindrical sample object W is measured. The distance between the sensor 82 and the surface of the sample object is then reduced byΔL, and the time t<SB POS="POST">2</SB>required for the ultrasonic wave outputted from the sensor 82 to be received by the sensor 82 after reflection on the surface of the sample object W is measured. The sound velocity v<SB POS="POST">1</SB>of an ultrasonic transmission medium is calculated using the equation v<SB POS="POST">1</SB>=ΔL/(t<SB POS="POST">1</SB>-t<SB POS="POST">2</SB>). The diameter D<SB POS="POST">0</SB>of a reference sample object W is calculated from the distance L<SB POS="POST">1</SB>between the sensor 82 and the center of the sample object and the L<SB POS="POST">2</SB>based on the ultrasonic measuring using the sound velocity v<SB POS="POST">1</SB>, so that the sound velocity v<SB POS="POST">2</SB>of the reference work piece W is computed from the time required for the ultrasonic wave to travel back and forth across the diameter D<SB POS="POST">0</SB>. The diameter D of the workpiece is calculated, using the difference in arrival time to the sensor 82 between the reflection wave from the surface of the workpiece and the reflection wave from the rear face, and the sound velocity v<SB POS="POST">2</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
