695 - Quantification of the uncertainty of measurement of the normal incidence absorption coefficient
Ramis Soriano J., Alba Fernández J., Juliá Sanchis E., Escuder Silla E.
Abstract
The tube of Kundt is one of the habitual elements in the measurement of acoustic characteristics of the materials. In order to determine the impedance and the absorption coefficient, it is used a tube that it is described in norm ISO 10534 (Acoustic determination of sound absorption coefficient and impedance or admittance by the impedance tube. Part I (1996): Standing wave ratio method. Part II (1998): Transfer Function method). The usual technique is based on a random signal (white noise or similar). It is emitted and the signal is recorded just in microphones put before of the sample. The tube must be sufficiently long or absorbent so that the following reflections in the loudspeaker, do not modify the results substantially. An alternative technique is to use MLS sequences. It permit separate the information of the reflection in the material of the detrimental reflections. The object of this work is to evaluate the uncertainty in the results of the measurements realized using both techniques.
Citation
Ramis Soriano J.; Alba Fernández J.; Juliá Sanchis E.; Escuder Silla E.: Quantification of the uncertainty of measurement of the normal incidence absorption coefficient, CD-ROM Proceedings of the Thirtheenth International Congress on Sound and Vibration (ICSV13), July 2-6, 2006, Vienna, Austria, Eds.: Eberhardsteiner, J.; Mang, H.A.; Waubke, H., Publisher: Vienna University of Technology, Austria, ISBN: 3-9501554-5-7
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