| 摘要 |
PROBLEM TO BE SOLVED: To measure surface wave sound speed with precision and without skill by making judgement for position on the time axis of a rising part and zero-cross point of wave form easy and sure. SOLUTION: From the control of a system control part 13, a moving mechanism part 11 sequentially changes the interval of super sonic wave sending/ receiving devices 12a and 12b. The reception signal obtained by sending/receiving super sonic wave pulse at this interval is converted into digital signal with an A/D converter 17, and then stored in a wave form storing device 13a. The reception wave form data read out of the wave form storing device 13a by a personal computer 19 is represented with the interval of super sonic wave sending/receiving devices 12a and 12b represented on a horizontal axis and the propagation time of reception wave form on the vertical axis, and the figure representing the amplitude of reception wave form as light and dark, ranging from black color to white color, is generated, and displayed on a display 19a. Further, the inclination of the part where the identical phase part where gradation of light/dark is equal becomes linear, in the figure displayed on a screen, is calculated, for calculating the sound speed of surface wave. |
