Using a Planar Array of MEMS Microphones to Obtain Acoustic Images of a Fan Matrix

This paper proposes the use of a signal acquisition and processing system based on an 8 x 8 planar array of MEMS (Microelectromechanical Systems) microphones to obtain acoustic images of a fan matrix. A 3 x 3 matrix of PC fans has been implemented to perform the study. Some tests to obtain the acoustic images of the individual fans and of the whole matrix have been defined and have been carried out inside an anechoic chamber. The nonstationary signals received by each MEMS microphone and their corresponding spectra have been analyzed, as well as the corresponding acoustic images. The analysis of the acoustic signals spectra reveals the resonance frequency of the individual fans. The obtained results reveal the feasibility of the proposed system to obtained acoustic images of a fan matrix and of its individual fans, in this last case, in order to estimate the real position of the fan inside the matrix.