ASTM E477 – 13 Laboratory Measurements of Acoustical and Airflow Performance of Duct Liner Materials and Prefabricated Silencers

Scope:

ASTM E477-13 is a highly significant method for the determination of the acoustical and airflow performance of duct liner materials. For example, duct silencers are used to control sound propagation through ventilation ducts. It can be used to estimate the reduction in fan sound levels in ducted airflow systems caused by including a sound-attenuating device in the system. Therefore, it is of great significance.

Procedure:

When insertion loss is measured with air flowing through the test specimen, the measured quantity is dynamic insertion loss. Measurements are made in a series of frequency bands because insertion loss is a function of frequency. Noise generated by air flowing through the test specimen is measured in the reverberation room and expressed in terms of a computed sound power level within each frequency band. The pressure drop and airflow may be measured with a variety of standard acceptable instrumentation. It is the intent of this test method that corrections due to background and flanking noise be eliminated or minimized as much as possible.

Result:

In this way, by performing ASTM E477 – 13, Acoustical and Airflow Performance of Duct Liner Materials and Prefabricated Silencers can be easily measured.