2000 Volume 24 Issue 2 Pages 136-143
In the surface intensity measurements, a microphone and an accelerometer are used to measure surface acoustical pressure and normal velocity of vibrating structure. Therefore, an efficient technique for setting two different sensors on vibrating structure is required to measure the surface intensity at multiple points. In this study, we developed a sensor-probe whose microphone was mounted on an accelerometer in order to simplify setting the sensors on vibrating structure. In the experiment, the intensity was simultaneously measured at multiple points of a vibrating structure using a sensor-probe array. The result showed that a newly developed technique can estimate the intensity radiated from a steel sheet where an exciting point had been traveling. The measurement error is also caused by instrumental phase mismatch. We calibrated the phase characteristics of the microphone in sound fields near vibrating surfaces. The correction coefficients were determined by comparing the phase characteristics of the microphone and the vibrating surface of a piezo-electric shaker. The intensity measurements were carried out with and without phase correction of the instrumentation. The result showed that the effect of the phase correction was necessary in the higher frequency range above 2kHz.
