BS 4857-2:1978
Current
The latest, up-to-date edition.
Hardcopy , PDF
English
31-08-1978
Foreword
Cooperating organizations
Method
Section one. General
1 Scope
2 References
3 Definitions
4 Nomenclature
5 General test requirements
6 Instrumentation
7 Test methods
8 Rating tests
9 Reporting of test results
Section two. Test methods
10 General
11 Application
12 Precision
13 Instrumentation
14 Installation
15 Quantities to be measured
16 Discrete frequency components
17 Method of measurement
18 Determination of sound power level
19 Background noise
Appendices
A Method of testing and rating quiet equipment
B Quiet air supply for acoustic testing and rating
Tables
1 Correction conditions for background noise
2 Range of accuracy in determining sound power levels
of broad band sources in reverberation rooms
3 Bandwidths
4 Significant discrete frequencies
5 Number of microphone stations
6 Standard deviations
7 Minimum requirements for traverse path
Figures
1 Arrangement of equipment for insertion loss test
2 Typical arrangement for unit-out test
3 End reflection correction
4 Arrangement of equipment for generated noise test;
noise radiated, in direction of outlet
5 Arrangement of equipment for generated noise test;
noise radiated, in direction of inlet
6 Arrangement of equipment for casing radiation test
7 Example of typical reference sound source
8 Extrapolation of LW data on octave bands 4, 5, 6 and
7 below minimum measurable value of 30 dB
9 Equipment for quiet air supply
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