Standard Test Method for Airflow Resistance of Acoustical Materials

Importancia y uso:

5.1 The specific airflow resistance of an acoustical material is one of the properties that determine its sound-absorptive and sound-transmitting properties. Measurement of specific airflow resistance is useful during product development, for quality control during manufacture, and for specification purposes.

5.2 Valid measurements are made only in the region of laminar airflow where, aside from random measurement errors, the airflow resistance (R = P/U) is constant. When the airflow is turbulent, the apparent airflow resistance increases with an increase of volume velocity and the term “airflow resistance” does not apply.

5.3 The specific airflow resistance measured by this test method may differ from the specific resistance measured by the impedance tube method in Test Method E384 for two reasons. In the presence of sound, the particle velocity inside a porous material is alternating while in this test method, the velocity is constant and in one direction only. Also, the particle velocity inside a porous material is not the same as the linear velocity measured outside the specimen.

Subcomité:

E33.01

Referida por:

C0800-19, C0634-22, E2813-24

Volúmen:

04.06

Número ICS:

91.120.20 (Acoustics in buildings. Sound insulation)

Palabras clave:

absorption; acoustical materials; airflow resistance; airflow resistivity ;