In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 40, No. 2 ( 1966-08-01), p. 421-427
Kurzfassung:
The acoustic beam from a circular plane piston 1.01 cm in radius, driven sinusoidally to finite amplitudes in water, at 2.58 Mc/sec, has been mapped with two quite different small probes about 2 mm in diameter. Equivalent acoustic pressures at the source ranged from 0.2 to 6.0 atm. The fundamental component and the self-generated second and third harmonics were filtered separately, and beam patterns were photographed on a CRO screen. Fine structure down to the size of the probes was recorded. Reliability was demonstrated both by agreement of the two different probes and by measurements on theoretically known patterns at very low amplitude; maxima and minima were, respectively, lowered and raised in the records, but approximate analytical corrections are available. Rough estimates (±30%) of sensitivity showed that both probes were substantially linear and stable. The second-harmonic component of the beam was found to be more nearly cylindrically collimated than was the fundamental. Fine structure in second and third harmonics was rather less complex than in the fundamental, and different in detail, yet the higher harmonics were not much nearer than the fundamental to being collimated plane waves.
Materialart:
Online-Ressource
ISSN:
0001-4966
,
1520-8524
Sprache:
Englisch
Verlag:
Acoustical Society of America (ASA)
Publikationsdatum:
1966
ZDB Id:
1461063-2
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