| Measurement of the resistivity of porous materials with an alternating air-flow method. | |
| | |
MedLine Citation:
|
PMID: 21361434 Owner: NLM Status: In-Data-Review |
Abstract/OtherAbstract:
|
Air-flow resistivity is a main parameter governing the acoustic behavior of porous materials for sound absorption. The international standard ISO 9053 specifies two different methods to measure the air-flow resistivity, namely a steady-state air-flow method and an alternating air-flow method. The latter is realized by the measurement of the sound pressure at 2 Hz in a small rigid volume closed partially by the test sample. This cavity is excited with a known volume-velocity sound source implemented often with a motor-driven piston oscillating with prescribed area and displacement magnitude. Measurements at 2 Hz require special instrumentation and care. The authors suggest an alternating air-flow method based on the ratio of sound pressures measured at frequencies higher than 2 Hz inside two cavities coupled through a conventional loudspeaker. The basic method showed that the imaginary part of the sound pressure ratio is useful for the evaluation of the air-flow resistance. Criteria are discussed about the choice of a frequency range suitable to perform simplified calculations with respect to the basic method. These criteria depend on the sample thickness, its nonacoustic parameters, and the measurement apparatus as well. The proposed measurement method was tested successfully with various types of acoustic materials. |
| | |
Authors:
|
Raffaele Dragonetti; Carmine Ianniello; Rosario A Romano |
Related Documents
:
|
1200574 - Some observations on blood microfilters. 22370824 - Clinical and laboratory alterations in dogs naturally infected by leishmania chagasi. 7445064 - The use of freeze-dried blood in the membrane feeding of tsetse flies (glossina p. palp... 16197934 - Quantitative determination of guanidinoacetate and creatine in dried blood spot by flow... 11810644 - New technique using galactose-specific lectin for isolation of fetal cells from materna... 17117064 - Quantification of perfusion modes in terms of surplus hemodynamic energy levels in a si... |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: The Journal of the Acoustical Society of America Volume: 129 ISSN: 1520-8524 ISO Abbreviation: J. Acoust. Soc. Am. Publication Date: 2011 Feb |
Date Detail:
|
Created Date: 2011-03-02 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 7503051 Medline TA: J Acoust Soc Am Country: United States |
Other Details:
|
Languages: eng Pagination: 753 Citation Subset: IM |
Affiliation:
|
Dipartimento di Energetica, Termofluidoidinamica applicata e Condizionamenti ambientali, Università di Napoli Federico II, piazzale Tecchio 80, 80125 Napoli, Italy. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Bayesian characterization of multiple-slope sound energy decays in coupled-volume systems.
Next Document: Irregular array motion and extended integration for the suppression of spatial aliasing in passive s...