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ISO 3743-2:2018 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special reverberation test rooms >
ISO 3743-2:2018 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special reverberation test rooms, 2018
- Foreword
- Introduction
- 1 Scope
- 2 Normative references
- 3 Terms and definitions
- 4 Principle
- 5 Noise source
- 6 Requirements for special reverberation test room
- 6.1 General
- 6.2 Volume of test room
- 6.3 Reverberation time of test room
- 6.4 Surface treatment
- 6.5 Criterion for background noise
- 6.6 Criteria for temperature and humidity
- 6.7 Evaluation of suitability of test room
- 7 Instrumentation
- 7.1 General
- 7.2 Microphone and its associated cable
- 7.3 Amplifier and weighting network
- 7.4 Octave-band filters
- 7.5 Squaring and averaging circuits and indicating device
- 7.6 Frequency response of the instrumentation system
- 7.7 Calibration
- 8 Installation and operation of source under test
- 8.1 General
- 8.2 Source location
- 8.3 Source mounting
- 8.4 Auxiliary equipment
- 8.5 Operation of source during the test
- 9 Measurements in test room
- 9.1 General
- 9.2 Period of observation
- 9.3 Microphone positions
- 9.4 Number of microphones and source positions
- 9.5 Criteria for the presence of spectral irregularities
- 9.6 Averaging technique with moving microphones
- 9.6.1 General
- 9.6.2 Path length for continuous averaging
- 9.6.3 Location of path within test room
- 9.6.4 Speed of traverse
- 9.7 Array of fixed microphones
- 9.8 Correction for background sound pressure levels
- 10 Calculation of sound power levels
- 10.1 Calculation of mean band pressure levels
- 10.2 Direct method for determining sound power levels
- 10.3 Comparison method for determining band power levels
- 10.4 A-weighted sound power levels determined by the comparison method
- 11 Measurement uncertainty
- 11.1 Methodology
- 11.2 Determination of σomc
- 11.3 Determination of σR0
- 11.3.1 General
- 11.3.2 Round robin test
- 11.3.3 Modelling approach for σR0
- 11.4 Typical upper bound values of σR0
- 11.5 Total standard deviation σtot and expanded uncertainty U
- 12 Information to be recorded
- 12.1 General
- 12.2 Sound source under test
- 12.3 Acoustical environment
- 12.4 Instrumentation
- 12.5 Acoustical data
- 13 Information to be reported
- Annex A (normative) Characteristics and calibration of reference sound source
- Annex B (informative) Guidelines for the design of special reverberation test rooms
- Annex C (informative) Examples of suitable instrumentation systems
- Annex D (informative) Guidance on the development of information on measurement uncertainty
- Annex E (normative) Sound power level under reference meteorological conditions
- Annex F (normative) Calculation of A-weighted sound power levels from octave band levels
- Bibliography [Go to Page]