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GB/T 25077-2010: Acoustics -- Materials for acoustical applications -- Determination of airflow resistance
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| GB/T 25077-2010 | English | 214 |
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Acoustics -- Materials for acoustical applications -- Determination of airflow resistance
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GB/T 25077-2010
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Basic data | Standard ID | GB/T 25077-2010 (GB/T25077-2010) | | Description (Translated English) | Acoustics -- Materials for acoustical applications -- Determination of airflow resistance | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | A59 | | Classification of International Standard | 17.140 | | Word Count Estimation | 11,194 | | Date of Issue | 2010-09-02 | | Date of Implementation | 2011-04-01 | | Adopted Standard | ISO 9053-1991, IDT | | Regulation (derived from) | Announcement of Newly Approved National Standards No. 4 of 2010 (total 159) | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China | | Summary | This standard specifies the porous sound-absorbing material flow resistance measurement of the two methods, the specimen can be directly cut from the porous material products obtained NOTE: For there is laminar and turbulent flow characteristics References Appendix A. | GB/T 25077-2010: Acoustics -- Materials for acoustical applications -- Determination of airflow resistance
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Acoustics.Materials for acoustical applications.Determination of airflow resistance
ICS 17.140
A59
National Standards of People's Republic of China
Acoustics - Measurement of flow resistance of porous sound - absorbing materials
(ISO 9053..1991, IDT)
2010-09-02 release
2011-04-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People 's Republic of China
China National Standardization Management Committee released
Foreword
This standard is equivalent to the use of international standards ISO 9053..1991 "Acoustic porous sound absorption material flow resistance measurement" (English version).
This standard is subject to editorial changes to ISO 9053..1991 as required by GB/T 1.1.
Appendix A to this standard is an informative appendix.
This standard is proposed by the Chinese Academy of Sciences.
This standard is under the jurisdiction of the National Acoustics Standardization Technical Committee (SAC/TC17).
The drafting of this standard unit. Tongji University, China Academy of Building Research, Zhejiang Dafeng Industrial Co., Ltd.
The main drafters of this standard. Zhong Xiangzhang, Tan Hua, Xie Hong.
Introduction
The flow resistance of the porous material indirectly reflects some of the structural properties of the material. Flow resistance is used to establish some acoustic properties of material structures and materials
(E.g., sound absorption characteristics, attenuation characteristics, etc.).
Therefore, this standard has the following two purposes.
a) reflect the relationship between the acoustic properties of porous materials and the structure and production methods of their materials;
b) ensure product quality (quality control).
Acoustics - Measurement of flow resistance of porous sound - absorbing materials
1 Scope
This standard specifies two methods for flow resistance measurement of porous sound absorbing materials.
Specimens can be cut directly from the porous material.
Note. See Appendix A for references to airflow characteristics in laminar and turbulent flows.
2 terms and definitions
The following terms and definitions apply to this standard.
2.1
Flow resistance airflowresistance
The difference between the pressure on both sides of the specimen and the velocity of the air flow through the specimen. Is expressed by equation (1) in units of Pascal seconds per cubic meter (Pa ·
s/m3).
R = ΔpqV
(1)
Where.
Δp --- differential pressure on both sides of the specimen, in Pascal (Pa);
qV --- The velocity of the air flow through the specimen, in cubic meters per cubic meter (m3/s).
2.2
Specific resistance to flow resistance
Rs
The ratio of the differential pressure on both sides of the specimen to the average velocity of the air passing through the specimen, that is, the product of the flow resistance and the area. (2), the unit is
Pascal seconds per meter (Pa · s/m).
Rs = R · A (2)
Where.
R --- the flow resistance of the test piece, the unit is Pascal seconds per cubic meter (Pa · s/m3);
A - the cross-sectional area of the specimen perpendicular to the direction of the air flow, in square meters (m2).
2.3
Flow rate airflowresistivity
If the isotropic material, the flow resistivity is the specific resistance of the unit thickness of the material, that is, the flow resistance to the specimen thickness. By the formula (3) that single
The position is Pascal seconds per square meter (Pa · s/m2).
r = Rsd
(3)
Where.
Rs --- the specific flow resistance of the specimen, in units of Pascal seconds per meter (Pa · s/m);
d - the thickness of the specimen along the direction of the air, in meters (m).
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