| 摘要 |
PURPOSE:To perform the analysis of phenomena of noises and vibrations, by detecting the standing wave from the spectrum of the acoustic intensity obtained from the cross spectrum between two points and the average value of the sound pressures at the two points. CONSTITUTION:The sound pressure of an object to be measured is measured by microphones 2 and 3. The microphones 2 and 3 are connected to a memory part 4, and the memory part 4 is connected to an acoustic intensity computing part 5 and a sound pressure computing part 6. The computing part 5 obtains the acoustic intensity of a travelling wave based on the signal from the memory part 4. The computing parts 6 obtains the averaged value of the time fluctuation signals of the sound pressures of the microphones 2 and 3 sent from the memory part 4. A standing wave computing part 7 compares the outputs of the computing parts 5 and 6 and obtains the standing wave. |
