NBN EN ISO 7235 : 2009
Current
The latest, up-to-date edition.
ACOUSTICS - LABORATORY MEASUREMENT PROCEDURES FOR DUCTED SILENCERS AND AIR-TERMINAL UNITS - INSERTION LOSS, FLOW NOISE AND TOTAL PRESSURE LOSS
01-12-2013
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Test facilities and requirements for instrumentation
5.1 Purpose and types of test facilities
5.2 Equipment for acoustic testing of silencers
5.3 Equipment for acoustic testing of air-terminal
units
5.4 Equipment for flow testing
5.5 Equipment for dynamic testing
6 Test procedures
6.1 General
6.2 Insertion loss
6.3 Transmission loss
6.4 Sound power level of the flow noise (or regenerated
sound)
6.5 Volume flow rate and pressure loss coefficient
7 Information to be recorded
7.1 Description of the test object
7.2 Instrumentation
7.3 Sound-source equipment
7.4 Test, substitution and transmission ducts
7.5 Transitions
7.6 Anechoic termination
7.7 Reverberation room
7.8 Acoustical test results
7.9 Measurement uncertainty
8 Information to be reported
Annex A (normative) Design of the sound field excitation
equipment and qualification tests
Annex B (normative) Transmission element
Annex C (normative) Duct walls and limiting insertion
loss
Annex D (normative) Conversion of one-third-octave-band
attenuation values to octave-band attenuation
values
Annex E (normative) Measurements on large parallel-baffle
silencers
Annex F (normative) Test of longitudinal attenuation
Annex G (informative) Anechoic terminations
Annex H (informative) Examples of measurement
arrangements
Bibliography
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