Three-dimensional acoustic intensity measuring device

PURPOSE:To arrange a probe easily in the right direction by providing the probe composed of the first microphone installed on the tip of a shaft and the second, the third and the fourth microphones installed in positions separated mutually at an equal distance from this shaft so as to constitute the apexes of a regular tetrahedron. CONSTITUTION:A microphone P4 is installed on the tip of an installation shaft 20, and three microphones P1, P2 and P3 are also installed on respective arms 22 arid 26 and so on fixed to the shaft 20 so as to encircle the shaft 20. These four microphones P1, P2, P3 and P4 are set as the respective apexes of a regular tetrahedron. When a probe is constituted in this way, the extending direction of the shaft 20 can be set as the Z axis, and the extending direction of the arm 22 to fix the microphone P1 can be set as the Y axis, and the perpendicular direction to both the shaft 20 and the arm 22 can be seized as the X axis direction. Thereby, when acoustic intensity is measured, this probe can be arranged easily in the right direction.