• 01/562316 DC : DRAFT JULY 2001

    Superseded A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.

    BS EN ISO 7235 ACOUSTICS - LABORATORY MEASUREMENT PROCEDURES FOR DUCTED SILENCERS AND AIR-TERMINAL UNITS - INSERTION LOSS, FLOW NOISE AND TOTAL PRESSURE LOSS

    Available format(s): 

    Superseded date:  08-09-2003

    Language(s): 

    Published date:  23-11-2012

    Publisher:  British Standards Institution

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    Table of Contents - (Show below) - (Hide below)

    Foreword
    Introduction
    1 Scope
    2 Normative references
    3 Terms and definitions
    4 Symbols (and abbreviated terms)
    5 Test facilities and instrumentation
      5.1 Purpose and types of test facilities
      5.2 Acoustic testing of silencers
      5.3 Acoustic testing of air-terminal units
      5.4 Flow testing
      5.5 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
          A.1 General
          A.2 Modal filter for measurement without flow
          A.3 Sound field excitation equipment for measurement
              with flow
          A.4 Qualification tests
    Annex B (normative) Transmission element
          B.1 Design of a transmission element
          B.2 Measurement of the reflection coefficient of a
              transmission element
          B.3 Calculation of the transmission loss and reflection
              coefficient at the open end of a duct
    Annex C (normative) Duct walls and limiting insertion loss
          C.1 Flanking transmission
          C.2 Arrangements for determining the limiting insertion
              loss
    Annex D (normative) Conversion of one-third-octave-band
            attenuation values to octave-band attenuation values
    Annex E (normative) Measurement on large parallel-baffle
            silencers
    Annex F (normative) Test of longitudinal attenuation
    Annex G (informative) Anechoic terminations
          G.1 Guidelines for the design and construction of an
              anechoic termination
          G.2 Evaluation of performance
    Annex H (informative) Examples of measurement arrangements
    Bibliography

    General Product Information - (Show below) - (Hide below)

    Comment Closes On
    Committee EH/1/4
    Document Type Draft
    Publisher British Standards Institution
    Status Superseded
    Superseded By

    Standards Referencing This Book - (Show below) - (Hide below)

    IEC 60942:2003 Electroacoustics - Sound calibrators
    ISO 11820:1996 Acoustics — Measurements on silencers in situ
    ISO 3746:2010 Acoustics Determination of sound power levels and sound energy levels of noise sources using sound pressure Survey method using an enveloping measurement surface over a reflecting plane
    ISO 5135:1997 Acoustics Determination of sound power levels of noise from air-terminal devices, air-terminal units, dampers and valves by measurement in a reverberation room
    ISO 5167-1:2003 Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full Part 1: General principles and requirements
    ISO 9614-3:2002 Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 3: Precision method for measurement by scanning
    ISO 14163:1998 Acoustics — Guidelines for noise control by silencers
    ISO 5221:1984 Air distribution and air diffusion Rules to methods of measuring air flow rate in an air handling duct
    IEC 61260:1995 Electroacoustics - Octave-band and fractional-octave-band filters
    ISO 3714:1980 Oil of pennyroyal
    ISO 5136:2003 Acoustics — Determination of sound power radiated into a duct by fans and other air-moving devices — In-duct method
    IEC 60651:1979+AMD1:1993+AMD2:2000 CSV Sound level meters
    IEC 60804:2000 Integrating-averaging sound level meters
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