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ISO 7779:2018 Acoustics - Measurement of airborne noise emitted by information technology and telecommunications equipment >
ISO 7779:2018 Acoustics - Measurement of airborne noise emitted by information technology and telecommunications equipment, 2018
- Foreword
- Introduction
- 1 Scope
- 2 Normative references
- 3 Terms and definitions
- 3.1 General definitions
- 3.2 Acoustical definitions
- 3.3 Statistical definitions
- 4 Conformity requirements
- 5 Installation and operating conditions
- 5.1 Equipment installation
- 5.1.1 General
- 5.1.2 Floor-standing equipment
- 5.1.3 Table-top equipment
- 5.1.4 Wall-mounted equipment
- 5.1.5 Rack-mounted equipment
- 5.1.6 Hand-held equipment
- 5.1.7 Sub-assemblies
- 5.2 Input voltage and frequency
- 5.3 Equipment operation
- 6 Method for determination of sound power levels of equipment in reverberation test rooms
- 6.1 General
- 6.2 Measurement uncertainty
- 6.3 Test environment
- 6.3.1 General
- 6.3.2 Meteorological conditions
- 6.4 Instrumentation
- 6.4.1 General
- 6.4.2 The microphone and its associated cable
- 6.4.3 Frequency response of the instrumentation system
- 6.4.4 Reference sound source
- 6.4.5 Filter characteristics
- 6.4.6 Calibration
- 6.5 Installation and operation of equipment: general requirements
- 6.6 Microphone positions and source locations
- 6.6.1 General
- 6.6.2 Number of microphone positions, reference sound source locations and equipment locations
- 6.6.3 Microphone arrangement
- 6.7 Measurement of sound pressure level
- 6.7.1 General
- 6.7.2 Measurement duration
- 6.7.3 Corrections for background noise
- 6.8 Measurement of the sound pressure level of the reference sound source
- 6.9 Calculation of mean time-averaged band sound pressure level
- 6.10 Determination of sound power level
- 6.10.1 Calculation of band sound power levels
- 6.10.2 Calculation of A‑weighted sound power level
- 7 Method for determination of sound power levels of equipment under essentially free‑field conditions over a reflecting plane
- 7.1 General
- 7.2 Measurement uncertainty
- 7.3 Test environment
- 7.3.1 Essentially free field over a reflecting plane
- 7.3.2 Meteorological conditions
- 7.4 Instrumentation
- 7.4.1 General
- 7.4.2 The microphone and its associated cable
- 7.4.3 Frequency response of the instrumentation system
- 7.4.4 Reference sound source
- 7.4.5 Filter characteristics
- 7.4.6 Calibration
- 7.5 Installation and operation of equipment: General requirements
- 7.6 Measurement surface and microphone positions
- 7.6.1 General
- 7.6.2 Microphone positions on the measurement surface
- 7.7 Measurement of sound pressure levels
- 7.7.1 General
- 7.7.2 Measurement duration
- 7.7.3 Corrections for background noise
- 7.8 Calculation of surface sound pressure level
- 7.9 Determination of sound power levels
- 7.9.1 Calculation of band sound power levels
- 7.9.2 Calculation of A‑weighted sound power level
- 8 Method for determination of emission sound pressure levels at defined operator and bystander positions
- 8.1 General
- 8.2 Measurement uncertainty
- 8.3 Test environment
- 8.3.1 General
- 8.3.2 Meteorological conditions
- 8.4 Instrumentation
- 8.5 Installation and operation of equipment
- 8.6 Microphone positions
- 8.6.1 General
- 8.6.2 At the operator position(s)
- 8.6.3 At the bystander positions
- 8.6.4 Microphone orientation
- 8.7 Measurement of sound pressure levels
- 8.7.1 General
- 8.7.2 Measurement duration
- 8.7.3 Corrections for background noise
- 8.8 Determination of emission sound pressure levels
- 8.8.1 Calculation of band emission sound pressure levels
- 8.8.2 Calculation of A‑weighted emission sound pressure levels from band levels
- 8.8.3 Calculation of the mean emission sound pressure level at the bystander positions
- 9 Measurement uncertainty
- 10 Information to be recorded and reported
- 10.1 Information to be recorded
- 10.1.1 General
- 10.1.2 Equipment under test
- 10.1.3 Acoustical environment
- 10.1.4 Instrumentation
- 10.1.5 Acoustical data
- 10.2 Test report
- Annex A (normative) Test accessories
- Annex B (normative) Measurement surfaces
- Annex C (normative) Installation and operating conditions for specific equipment categories
- Annex D (informative) Identification and evaluation of prominent discrete tones
- Annex E (informative) Background information on the method formerly used for the detection of impulsive noise
- Bibliography [Go to Page]