Reproducibility experiments on measuring acoustical and related non-Acoustical parameters of porous media (round-robin tests)

A series of reproducibility experiments on the characterisation of acoustical parameters of selected samples of porous media is carried out on a range of porous samples in several independent laboratories in Europe and North America. The studied acoustical characteristics are the characteristic acoustic impedance and complex propagation constant. The data on the normal incidence, plane wave sound absorption coefficient is presented in this paper. The assessment of the related geometrical parameters required for model, namely the steady-state flow resistivity, porosity, tortuosity, viscous and thermal characteristic lengths and thermal permeability, will be discussed in the oral presentation. Detailed procedures related to sample preparation, installation are discussed together with data on the material property variation observed between individual material samples and laboratories.© (2006) by the International Institute of Acoustics & Vibration.