Flow resistance acoustic measurement methods

There are many acoustical methods proposed for measuring flow resistivity (Delany and Bazley, 1971 Smith and Parott, 1983). A method that uses a standard impedance tube directly to measure the static flow resistivity without any additional requirements to tube modification or sensor location change is described in ISO Standard, 10534-2 (1998) and by Tao et al. (2015). In the method, the specific acoustic impedance on the front surface of the test specimen is measured first by using the traditional transfer function method with the test specimen being placed against and with a known interval to the rigid termination, and then the characteristic impedance, the propagation constant, and the static flow resistivity are calculated based on the obtained impedance transfer functions. 

Picard, M.A., Solana, R, Urchuegfa, J.F., 1998. A method of measuring the dynamic flow resistance and the acoustic measurement of the effective static flow resistance in stratified rockwool samples. J. Sound Vib. 216 (3), 495-505. 

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