A speckle-interferometric setup for contactless measurements of the velocity of rayleigh ultrasonic waves

• Published in: Instruments and experimental techniques (New York) Vol. 53; no. 1; pp. 118 - 121
• Main Authors: Vladimirov, A. P., Gorkunov, E. S., Eremin, P. S., Zadvorkin, S. M., Shadrin, M. V., Solov’ev, K. E.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 2010
• Subjects: Electrical Engineering; Measurement Science and Instrumentation; Physical Chemistry; Physics; Physics and Astronomy; Steel 20X13; Rayleigh Wave Velocity; Wave Train; Irradiate Area; Rayleigh Wave
• ISSN: 0020-4412; 1608-3180
• DOI: 10.1134/S0020441210010197

The velocity of a Rayleigh wave was determined by measuring its propagation time between two Iaser-illuminated small areas of a rough surface. It is sh own that, if a Rayleigh wave passes over these areas, a photodiode twice detects signals proportional to the surface displacement in the speckle overlap region. In contrast to the previous variant, signal-distorting reflections are eliminated in the instrument. A sample holder excluding adjustment of the interferometer upon a change in the object size has been manufactured. A new technique for determining the time interval between two signals is used. The instrument operates at a frequency of 5 MHz, and the distance between the areas is adjusted in the range 5–100 mm. The rms deviation of the velocity from the average value for ten measurements is 8 × 10–4.