2.3. Experimental apparatuses and methods for identification of vibration sources
An experiment was conducted to identify how vibrations during operation contribute to the overall sound; each part of the suction housing was tested by attaching an accelerometer to the part and measuring the vibrations there during operation. The intent of this experiment was to determine not only the vibrations of certain frequencies occurring at particular locations, but also the contributions of these vibrations to the overall emitted sound.
An accelerometer was used to measure the 14 areas noted in Fig. 4. In subsequent data processing, the contribution was evaluated using an auto-spectrum of each signal and a cross-spectrum of two signals, namely, the vibration signal at the chosen location
and the corresponding sound pressure signal measured by the microphone.