NF EN ISO 3747
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.
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.
<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>
- Avant-proposiv
- Introductionv
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1 Domaine d'application1
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2 Références normatives2
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3 Termes et définitions2
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4 Environnement d'essai6
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5 Appareillage et dispositif de mesure6
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6 Emplacement, installation et fonctionnement de la source de bruit en essai7
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7 Méthode de mesure8
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8 Calcul des niveaux de puissance acoustique et des niveaux d'énergie acoustique12
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9 Incertitude de mesure16
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10 Informations à enregistrer20
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11 Informations à consigner dans le rapport d'essai21
- Annexe A (normative) Évaluation de l'amplification du niveau de pression acoustique à une distance donnée22
- 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 référence23
- Annexe C (normative) Niveau de puissance acoustique et niveau d'énergie acoustique dans les conditions météorologiques de référence28
- 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'octave30
- Annexe E (informative) Lignes directrices pour l'élaboration de données sur l'incertitude de mesure32
- Bibliographie43
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