NF EN ISO 3747

NF EN ISO 3747

February 2011
Standard Current

Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering/survey methods for use in situ in a reverberant environment

ISO 3747:2010 specifies a method for determining the sound power level or sound energy level of a noise source by comparing measured sound pressure levels emitted by a noise source (machinery or equipment) mounted in situ in a reverberant environment, with those from a calibrated reference sound source. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one octave, is calculated using those measurements. The sound power level or sound energy level with frequency A-weighting applied is calculated using the octave-band levels. The method specified in ISO 3747:2010 is suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. The method is primarily applicable to sources which emit broad-band noise. It can, however, also be used for sources which emit narrow-band noise or discrete tones, although there is a possiblity that the measurement reproducibility is then degraded. The noise source under test can be a device, machine, component or sub-assembly, especially one which is non-movable. The test environment that is applicable for measurements made in accordance with ISO 3747:2010 is a room where the sound pressure level at the microphone positions depends mainly on reflections from the room surfaces. In measurements of ISO 12001:1996, accuracy grade 2 (engineering grade), background noise in the test environment is low compared to that of the noise source or reference sound source. Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3747:2010, for measurements made in octave bands and for A-weighted frequency calculations performed on them. The reproducibility conforms with that of either ISO 12001:1996, accuracy grade 2 (engineering grade) or ISO 12001:1996, accuracy grade 3 (survey grade), depending on the extent to which the requirements concerning the test environment are met.

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Main informations

Collections

National standards and national normative documents

Publication date

February 2011

Number of pages

54 p.

Reference

NF EN ISO 3747

ICS Codes

17.140.01   Acoustic measurements and noise abatement in general

Classification index

S31-067

Print number

1 - 11/02/2011

International kinship

European kinship

EN ISO 3747:2010
Sumary
Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering/survey methods for use in situ in a reverberant environment

ISO 3747:2010 specifies a method for determining the sound power level or sound energy level of a noise source by comparing measured sound pressure levels emitted by a noise source (machinery or equipment) mounted in situ in a reverberant environment, with those from a calibrated reference sound source. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one octave, is calculated using those measurements. The sound power level or sound energy level with frequency A-weighting applied is calculated using the octave-band levels.

The method specified in ISO 3747:2010 is suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. The method is primarily applicable to sources which emit broad-band noise. It can, however, also be used for sources which emit narrow-band noise or discrete tones, although there is a possiblity that the measurement reproducibility is then degraded.

The noise source under test can be a device, machine, component or sub-assembly, especially one which is non-movable.

The test environment that is applicable for measurements made in accordance with ISO 3747:2010 is a room where the sound pressure level at the microphone positions depends mainly on reflections from the room surfaces. In measurements of ISO 12001:1996, accuracy grade 2 (engineering grade), background noise in the test environment is low compared to that of the noise source or reference sound source.

Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3747:2010, for measurements made in octave bands and for A-weighted frequency calculations performed on them. The reproducibility conforms with that of either ISO 12001:1996, accuracy grade 2 (engineering grade) or ISO 12001:1996, accuracy grade 3 (survey grade), depending on the extent to which the requirements concerning the test environment are met.

Replaced standards (1)
NF EN ISO 3747
November 2009
Standard Cancelled
Acoustics - Determination of sound power levels of noise sources using sound pressure - Comparison method in situ

<p> La présente Norme internationale s'applique à tous les types d'environnements d'essai autres que celui rencontré en laboratoire, à condition que le niveau de bruit de fond soit suffisamment faible et que le niveau de pression acoustique aux différentes positions de microphone dépende principalement des réflexions par les surfaces de la salle. <br/> <br/>NOTE L'ISO 3744 ou l'ISO 9614 peut fournir des méthodes alternatives. La présente Norme internationale s'applique principalement aux sources qui émettent un bruit à large bande. Cependant, elle peut également s'appliquer aux sources qui émettent un bruit à bande étroite ou des sons purs, bien que l'incertitude de mesure puisse alors devenir plus importante que celle indiquée ici. <br/> <br/>NOTE L'ISO 9614 peut être utilisée comme norme alternative pour les sources de bruit qui émettent un bruit stable. </p>

Table of contents
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  • Avant-propos
    iv
  • Introduction
    v
  • 1 Domaine d'application
    1
  • 2 Références normatives
    2
  • 3 Termes et définitions
    2
  • 4 Environnement d'essai
    6
  • 5 Appareillage et dispositif de mesure
    6
  • 6 Emplacement, installation et fonctionnement de la source de bruit en essai
    7
  • 7 Méthode de mesure
    8
  • 8 Calcul des niveaux de puissance acoustique et des niveaux d'énergie acoustique
    12
  • 9 Incertitude de mesure
    16
  • 10 Informations à enregistrer
    20
  • 11 Informations à consigner dans le rapport d'essai
    21
  • Annexe A (normative) Évaluation de l'amplification du niveau de pression acoustique à une distance donnée
    22
  • Annexe B (informative) Recommandations pour l'emplacement de la source sonore de référence et des microphones, si seulement une position est utilisée pour la source sonore de référence
    23
  • Annexe C (normative) Niveau de puissance acoustique et niveau d'énergie acoustique dans les conditions météorologiques de référence
    28
  • Annexe D (normative) Calcul des niveaux de puissance acoustique pondérés A et des niveaux d'énergie acoustique pondérés A à partir des niveaux par bande d'octave
    30
  • Annexe E (informative) Lignes directrices pour l'élaboration de données sur l'incertitude de mesure
    32
  • Bibliographie
    43
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