BS 4718:1971
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
Methods of test for silencers for air distribution systems
Hardcopy , PDF
08-09-2003
English
22-04-1971
Co-operating organizations
Foreword
Methods of test
1 General
1.1 Scope
1.2 General
1.3 Definitions
1.4 Symbols
1.5 Instrumentation
1.6 Installation
1.7 Quantities to be measured
1.8 Methods of measurement
1.9 Thermal environment
1.10 Accuracy of measurements
2 Measurement of static insertion loss
2.1 General requirements
2.2 The in-duct method
2.3 The diffuse field method
3 Measurement of generated noise loss
3.1 General requirements
3.2 Diffuse field: direct method
3.3 Diffuse field: substitution method
4 Measurement of pressure loss
4.1 Test methods
4.2 Presentation of results
Appendices
A Calculation of mean band sound pressure level
B End reflection
C Typical coupler and anechoic termination
D Illustration of reference sound source
E Extrapolation from results of individual tests
F Measurement of casing radiation
Figures
1 Substitution duct arrangements
2 Arrangement of test installation for in-duct tests
3 Microphone positions at in-duct measuring plane
4 Arrangement of test installation: diffuse field
method
5 Typical arrangement of installation for generated
noise level measurement
6 Positioning of reference sound source, diffuse
field substitution method
7 Installation for pressure loss measurements
Access your standards online with a subscription
Features
-
Simple online access to standards, technical information and regulations.
-
Critical updates of standards and customisable alerts and notifications.
-
Multi-user online standards collection: secure, flexible and cost effective.