| 摘要 |
PURPOSE:To make it possible to crystal face measure crystal face index using ultrasonic wave harmless for human body by a method wherein a reflection wave signal is detected in the form of complex amount and subjected to Fourier transform in order to determine the natural reflection function of a sample and then the surface wave speed of the sample is detected and compared with a known surface wave speed. CONSTITUTION:A point on the surface of a sample 6 is irradiated with ultrasonic wave while shifting the focal point of an acoustic lens 5 in Z direction. Reflected wave is then measured to obtain a V(z) data which is stored in the V(z) data are 18a of a memory 18. Upon finish of measurement of the V(z) data, a CPU 17 reads out a Fourier transform operation program from a transform operation program area 18b and subjects the V(z) data stored in the area 18a to inverse Fourier transform thus determining an average reflection function. Subsequently, the CPU 17 reads out a surface wave detection program from an area 18d and detects the surface wave speed. The detected value is compared with a surface wave speed data predetermined for each crystal face thus measuring the crystal face index of the sample 6. |
