In this paper, a method of measuring acoustic intensity automatically is presented. The method uses measur-ments of the cross spectrum of the pressures at two closely spaced microphones. The acoustic intensity probe used is composed of two microphones which are arranged in parallel and with a short distance slided along those axes, and combined symmetrically with respect to a holder axis. The holder can be turned around its axis by steps of a constant angle for measuring three directional components of an acoustic intensity vector. The acoustic intensity at a field point can be automatically measured by using such composed microphones. A transfer function technique is used for approximately correcting the phase-mismatch error between the instru-mentation of the signal channels of two microphones. This method of measuring acoustic intensity automatical-ly is actually applied to a visualization technque of the flow pattern of sound energy emitted from one aperture of an enclosure with a speaker inside. The experimental results show that the acoustic intensity probe used is an appropriate sensor for the auto-matic measuremend of spatial acoustic intensity vectors.
3次元音響インテンシティの自動計測用プローブ
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