Conference paper
Ultrasound pulse-echo measurements on rough surfaces with linear array transducers
The echo from planar surfaces with rms roughness, Rq, in the range from 0-155 μm was measured with a clinical linear array transducer at different angles of incidence at 6 MHz and 12 MHz. The echo-pulse from the surfaces was isolated with an equal sized window and the power of the echo-pulse was calculated.
The power of the echo from the smooth surface (Rq = 0) is highly angle-dependent due to a high degree of specular reflection. Within the angular range considered here, -10° to 10°, the variation spans a range of 18 dB at both 6 MHz and 12 MHz. When roughness increases, the angle-dependence decreases, as the echo process gradually changes from pure reflection to being predominantly governed by backscattering.
The power of the echoes from the two roughest surfaces (Rq = 115 μm and 155 μm) are largely independent of angle at both 6 MHz and 12 MHz with a variation of 2 dB in the angular range from -10° to 10°. The least rough surfaces (Rq = 32 μm and 89 μm) have responses in between with a higher degree of angle-dependence at 6 MHz than at 12 MHz.
Language: | English |
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Publisher: | American Institute of Physics |
Year: | 2012 |
Pages: | 211-214 |
Proceedings: | International Congress on Ultrasonics |
Series: | Aip Conference Proceedings |
ISSN: | 15517616 and 0094243x |
Types: | Conference paper |
DOI: | 10.1063/1.3703173 |
ORCIDs: | Wilhjelm, Jens E. and Jensen, Jørgen Arendt |