NF EN ISO 3744

NF EN ISO 3744

February 2012
Standard Current

Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for an essentially free field over a reflecting plane

ISO 3744:2010 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in an environment that approximates to an acoustic free field near one or more reflecting planes. 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 or with frequency A-weighting applied, is calculated using those measurements. The methods specified in ISO 3744:2010 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. ISO 3744:2010 is applicable to all types and sizes of noise source (e.g. stationary or slowly moving plant, installation, machine, component or sub-assembly), provided the conditions for the measurements can be met. The test environments that are applicable for measurements made in accordance with ISO 3744:2010 can be located indoors or outdoors, with one or more sound-reflecting planes present on or near which the noise source under test is mounted. The ideal environment is a completely open space with no bounding or reflecting surfaces other than the reflecting plane(s) (such as that provided by a qualified hemi-anechoic chamber), but procedures are given for applying corrections (within limits that are specified) in the case of environments that are less than ideal. Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3744:2010, for measurements made in limited bands of frequency and with frequency A-weighting applied. The uncertainty conforms to ISO 12001:1996, accuracy grade 2 (engineering grade).

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Main informations

Collections

National standards and national normative documents

Publication date

February 2012

Number of pages

90 p.

Reference

NF EN ISO 3744

ICS Codes

17.140.01   Acoustic measurements and noise abatement in general

Classification index

S31-025

Print number

1 - 13/01/2012

International kinship

European kinship

EN ISO 3744:2010
Sumary
Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for an essentially free field over a reflecting plane

ISO 3744:2010 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in an environment that approximates to an acoustic free field near one or more reflecting planes. 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 or with frequency A-weighting applied, is calculated using those measurements.

The methods specified in ISO 3744:2010 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001.

ISO 3744:2010 is applicable to all types and sizes of noise source (e.g. stationary or slowly moving plant, installation, machine, component or sub-assembly), provided the conditions for the measurements can be met.

The test environments that are applicable for measurements made in accordance with ISO 3744:2010 can be located indoors or outdoors, with one or more sound-reflecting planes present on or near which the noise source under test is mounted. The ideal environment is a completely open space with no bounding or reflecting surfaces other than the reflecting plane(s) (such as that provided by a qualified hemi-anechoic chamber), but procedures are given for applying corrections (within limits that are specified) in the case of environments that are less than ideal.

Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3744:2010, for measurements made in limited bands of frequency and with frequency A-weighting applied. The uncertainty conforms to ISO 12001:1996, accuracy grade 2 (engineering grade).

Replaced standards (1)
NF EN ISO 3744
November 2009
Standard Cancelled
Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane

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
    8
  • 5 Appareillage
    12
  • 6 Définition, emplacement, installation et fonctionnement de la source de bruit en essai
    12
  • 7 Parallélépipède de référence et surface de mesure
    15
  • 8 Détermination des niveaux de puissance acoustique et des niveaux d'énergie acoustique
    19
  • 9 Incertitude de mesure
    27
  • 10 Informations à enregistrer
    31
  • 11 Rapport d'essai
    32
  • Annexe A (normative) Méthodes de qualification de l'environnement acoustique
    33
  • Annexe B (normative) Réseaux microphoniques sur une surface de mesure hémisphérique
    38
  • Annexe C (normative) Réseaux microphoniques sur une surface de mesure parallélépipédique
    45
  • Annexe D (informative) Réseaux microphoniques sur une surface de mesure cylindrique
    56
  • Annexe E (normative) Calcul des niveaux de puissance acoustique pondérés A et des niveaux d'énergie acoustique pondérés A à partir des niveaux par bande de fréquences
    61
  • Annexe F (normative) Autre réseau microphonique possible sur une surface de mesure hémisphérique pour des mesurages directs des niveaux de pression acoustique pondérés A
    63
  • Annexe G (normative) Niveau de puissance acoustique et niveau d'énergie acoustique dans les conditions météorologiques de référence
    66
  • Annexe H (informative) Lignes directrices pour l'élaboration de données sur l'incertitude de mesure
    68
  • Bibliographie
    79
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