EN ISO 11204:2010

Acoustics - Noise emitted by machinery and equipment - Determination of emission sound pressure levels at a work station and at other specified positions applying accurate environmental corrections (ISO 11204:2010)

ISO 11204:2010 specifies a method for determining the emission sound pressure levels of machinery or equipment, at a work station and at other specified positions nearby, in any environment which meets certain qualification requirements. A work station is occupied by an operator and may be located in open space, in the room where the source under test operates, in a cab fixed to the source under test, or in an enclosure remote from the source under test. One or more specified positions may be located in the vicinity of a work station, or in the vicinity of an attended or unattended machine. Such positions are sometimes referred to as bystander positions.
Emission sound pressure levels are determined as A-weighted levels. Additionally, levels in frequency bands and C-weighted peak emission sound pressure levels can be determined in accordance with ISO 11204:2010, if required.
A method is given for determining a local environmental correction (subject to a specified limiting maximum value) to be applied to the measured sound pressure levels to exclude the effects of reflections from reflecting surfaces other than the plane on which the source under test is placed. This correction is based upon the mean sound pressure level on a measurement surface, the sound pressure level measured at a specified position, and either an environmental correction or the equivalent absorption area of the test room.
With the method specified in ISO 11204:2010 results of accuracy grade 2 (engineering grade) or accuracy grade 3 (survey grade) are obtained. Corrections are applied for background noise and, as described above, for the acoustic environment. Instructions are given for the mounting and operation of the source under test and for the choice of microphone positions for the work station and for other specified positions. One purpose of the measurements is to permit comparison of the performance of different units of a given family of machines, under defined environmental conditions and standardized mounting and operating conditions.
The method specified in ISO 11204:2010 is suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001.
The method specified in ISO 11204:2010 is applicable to all types and sizes of noise sources.
The type of test environment influences the accuracy of the determination of emission sound pressure levels. ISO 11204:2010 is applicable to an indoor or outdoor environment with one or more reflecting planes present, meeting specified requirements. These requirements on the room are less strict than those of ISO 11201, in particular regarding the acoustical quality of the environment.
ISO 11204:2010 is applicable to work stations and other specified positions where emission sound pressure levels are to be determined.
Appropriate positions where measurements may be made include the following: a) work station located in the vicinity of the source under test; this is the case for many industrial machines and domestic appliances; b) work station within a cab which is an integral part of the source under test; this is the case for many industrial trucks and earth-moving machines; c) work station within a partial or total enclosure (or behind a screen) supplied by the manufacturer as an integral part of the source under test; d) work station partially or totally enclosed by the source under test — this situation may be encountered with some large industrial machines; e) b

Akustik - Geräuschabstrahlung von Maschinen und Geräten - Bestimmung von Emissions-Schalldruckpegeln am Arbeitsplatz und an anderen festgelegten Orten unter Anwendung exakter Umgebungskorrekturen (ISO 11204:2010)

Diese Internationale Norm legt ein Verfahren zur Bestimmung der Emissions-Schalldruckpegel von
Maschinen oder Geräten am Arbeitsplatz und an anderen, sich in der Nähe befindenden, festgelegten Orten
in einer beliebigen Umgebung fest, die bestimmte Eignungskriterien erfüllt. Ein Arbeitsplatz wird von einer
Bedienungsperson eingenommen; er kann sich im Freien, in einem Raum, in dem die untersuchte Quelle
betrieben wird, in einer Kabine, die fest mit der untersuchten Quelle verbunden ist, oder in einem von der
untersuchten Quelle entfernt liegenden Bedienerstand befinden. Einer oder mehrere der festgelegten Orte
können im Umgebung eines Arbeitsplatzes oder im Umfeld einer bedienten oder unbeaufsichtigt betriebenen
Maschine liegen. Derartige Orte werden gelegentlich als „Nachbararbeitsplätze“ bezeichnet.
Emissions-Schalldruckpegel werden als A-bewertete Pegel bestimmt. Falls erforderlich, können zusätzlich
Pegel in Frequenzbändern und C-bewertete Emissions-Spitzenschalldruckpegel nach dieser Internationalen
Norm ermittelt werden.
ANMERKUNG 1 Der Inhalt der Normreihe ISO 11200 [15] bis ISO 11205 [19] ist in ISO 11200 [15] zusammengefasst.
Es wird ein Verfahren zur Bestimmung einer punktbezogenen Umgebungskorrektur (bis hin zu einem festgelegten
maximalen Grenzwert) angegeben, die auf die gemessenen Schalldruckpegel anzuwenden ist, um den
Einfluss aller anderen Reflexionsflächen als der Ebene, auf der die untersuchte Quelle aufgestellt ist, zu
eliminieren. Dieser Korrekturwert geht vom mittleren Schalldruckpegel auf einer Messfläche, dem an einem
festgelegten Ort gemessenen Schalldruckpegel und entweder einer Umgebungskorrektur oder der äquivalenten
Absorptionsfläche des Prüfraumes aus.
Mit dem in dieser Internationalen Norm festgelegten Verfahren werden Ergebnisse der Genauigkeitsklasse 2
oder der Genauigkeitsklasse 3 erzielt. Korrekturen werden bezüglich des Fremdgeräuschs und, wie oben
beschrieben, bezüglich der akustischen Umgebung vorgenommen.

Acoustique - Bruit émis par les machines et équipements - Détermination des niveaux de pression acoustique d'émission au poste de travail et en d'autres positions spécifiées en appliquant des corrections d'environnement exactes (ISO 11204:2010)

L'ISO 11204:2010 spécifie une méthode de détermination des niveaux de pression acoustique d'émission des machines et des équipements au poste de travail et en d'autres positions spécifiées proches, dans un quelconque environnement satisfaisant à certaines exigences de qualification. Le poste de travail occupé par un opérateur peut être situé dans un espace ouvert dans la salle où la source soumise à essai fonctionne, dans une cabine fixée à la source soumise à essai ou dans une enceinte située à distance de la source soumise à essai. Une ou plusieurs positions spécifiées peuvent se situer au voisinage du poste de travail ou d'une machine avec ou sans opérateur. Ces positions sont parfois appelées «positions d'assistant».
Les niveaux de pression acoustique d'émission sont déterminés en tant que niveaux pondérés A. En outre, les niveaux par bandes de fréquence et les niveaux de pression acoustique d'émission de crête pondérés C peuvent être déterminés selon l'ISO 11204:2010, si nécessaire.
Des méthodes sont fournies pour déterminer la correction locale d'environnement (soumise à une valeur limite maximale spécifiée) à appliquer aux niveaux de pression acoustique mesurés afin d'éliminer l'influence des surfaces réfléchissantes autres que le plan sur lequel repose la source soumise à essai. Cette correction est fondée sur l'aire d'absorption acoustique équivalente de la salle d'essai et sur les caractéristiques de rayonnement (emplacement de la source ou directivité au poste de travail).
La méthode spécifiée dans l'ISO 11204:2010 permet d'obtenir des résultats de classe de précision 2 (classe expertise) ou de classe de précision 3 (classe contrôle). Des corrections sont appliquées pour le bruit de fond et comme décrit ci-dessus pour l'environnement acoustique. Des instructions sont fournies pour le montage et le fonctionnement de la source soumise à essai ainsi que pour le choix des positions du microphone pour le poste de travail et pour d'autres positions spécifiées. Un des objets des mesurages est de permettre la comparaison des performances de différentes unités d'une famille donnée de machines, dans des conditions d'environnement définies et dans des conditions de montage et de fonctionnement normalisées.
La méthode spécifiée dans l'ISO 11204:2010 s'applique à tous les types de bruits (continus, discontinus, fluctuants, pics d'énergie acoustique isolés, etc.) définis dans l'ISO 12001.
La méthode spécifiée dans l'ISO 11204:2010 s'applique à tous les types et toutes les tailles de sources de bruit.
Le type d'environnement d'essai affecte la précision de la détermination des niveaux de pression acoustique d'émission. Pour l'ISO 11204:2010, toute salle répondant aux exigences spécifiées est utilisable. Ces exigences relatives à la salle sont moins strictes que celles de l'ISO 11201, notamment en ce qui concerne la qualité acoustique de l'environnement.
L'ISO 11204:2010 s'applique aux postes de travail et aux autres positions spécifiées auxquels les niveaux de pression acoustique d'émission doivent être mesurés.
Les positions appropriées où les mesurages peuvent être effectués incluent les positions suivantes: a) poste de travail situé au voisinage de la source soumise à essai, ce qui est le cas de nombreuses machines industrielles et de nombreux appareils domestiques; b) poste de travail à l'intérieur d'une cabine faisant partie intégrante de la machine soumise à essai; ce qui est le cas de nombreux véhicules industriels et engins de terra

Akustika - Emisija hrupa naprav in opreme - Merjenje emisijske ravni zvočnega tlaka na delovnem mestu in na drugih opredeljenih mestih z uporabo natančnih popravkov zaradi okolja (ISO 11204:2010)

Ta mednarodni standard določa metodo merjenja emisijske ravni zvočnega tlaka strojev ali opreme na delovnem mestu in na drugih bližnjih opredeljenih mestih, v kateremkoli okolju, ki izpolnjuje določene zahteve za kvalifikacijo. Delovno mesto zaseda operater in je lahko locirano na prostem, v sobi, kjer vir, ki je preskušan, deluje, v kabini pritrjeni na vir, ki je preskušan, ali ograjenem prostoru, ki je oddaljen od vira, ki je preskušan. Ena ali več določeni pozicij je lahko lociranih v bližini delovnega mesta, ali v bližini nadzorovanega ali nenadzorovanega stroja. Takšne pozicije se včasih omenja kot gledalske pozicije. Stopnje emisij zvočnega tlaka so določene kot A-ovrednotene stopnje. Poleg tega, če je potrebno, se stopnje v frekvenčnih pasovih in stopenj C-ovrednotenih vrhov zvočnega tlaka lahko določijo v skladu s tem mednarodnim standardom.

General Information

• Status: Published
• Publication Date: 14-May-2010
• Withdrawal Date: 29-Nov-2010
• ICS: 17.140.20 - Noise emitted by machines and equipment
• Technical Committee: CEN/TC 211 - Acuostics
• Drafting Committee: CEN/TC 211 - Acuostics
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 15-May-2010
• Completion Date: 15-May-2010
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Directive: 89/392/EEC - Machinery - Safety of machinery: general essential health and safety requirements
• Directive: 98/37/EC - Machinery
• Mandate: M/079 - Mandate to CEN and CENELEC for standardization in the field of machines
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Mandate: M/BC/CEN/88/13 - Standardization request to CEN/CENELEC relating to machinery
• Ref Project: SIST EN ISO 11204:2010 - Acoustics - Noise emitted by machinery and equipment - Determination of emission sound pressure levels at a work station and at other specified positions applying accurate environmental corrections (ISO 11204:2010)

Relations

• Replaces: EN ISO 11204:2009 - Acoustics - Noise emitted by machinery and equipment - Measurement of emission sound pressure levels at a work station and at other specified positions - Method requiring environmental corrections (ISO 11204:1995, including Cor 1:1997)
• Effective Date: 22-May-2010

Overview

EN ISO 11204:2010 (ISO 11204:2010) specifies a standardized method to determine noise emitted by machinery and equipment - specifically the emission sound pressure levels at a work station and at other specified (bystander) positions. The method is applicable in situ in indoor or outdoor environments that meet defined qualification requirements and uses accurate environmental corrections to exclude undesired reflections. Results are reported primarily as A‑weighted levels, with optional octave/one‑third‑octave band results and C‑weighted peak levels.

Key topics and requirements

• Scope and applicability
  • Measurement at an operator’s work station (open space, room, cab, or enclosure) and at nearby specified positions.
  • Suitable for all types of noise (steady, fluctuating, bursts) as defined in ISO 12001.
• Environmental correction
  • A local environmental correction (K) is determined to remove effects of reflections from surfaces other than the plane supporting the source.
  • Correction is based on the mean sound pressure on a measurement surface, the level at a specified position, and either an environmental correction or the room’s equivalent absorption area. A maximum limiting value applies.
• Measurement quantities & weighting
  • Primary reporting: A‑weighted emission sound pressure levels.
  • Optional: frequency‑band levels and C‑weighted peak levels.
• Accuracy and uncertainty
  • Procedure provides accuracy grade 2 (engineering grade) or grade 3 (survey grade) results.
  • Corrections for background noise and the acoustic environment are required; guidance on measurement uncertainty is included.
• Test setup
  • Instructions for mounting and operation of the source under test and for selecting microphone positions for work stations and bystander positions.
  • Applicable to all sizes and types of noise sources; environment qualification is less strict than ISO 11201.

Practical applications and users

• Who uses it:
  • Acoustic engineers, test laboratories, OEMs and manufacturers, occupational health & safety specialists, compliance and certification bodies.
• Typical uses:
  • Comparing noise emission between units of a machine family under standardized conditions.
  • Declaring and verifying emission sound pressure levels for product documentation and regulatory compliance (e.g., machinery directives).
  • Assessing operator exposure and nearby bystander noise in industrial, agricultural, construction, and consumer‑appliance contexts.

Related standards

• ISO 11200 - Overview and method selection for emission sound measurements
• ISO 11201 - Alternative procedures for work station measurements (stricter room requirements)
• ISO 11202 - Procedures for impulsive/noise events (differs in directivity approach)
• ISO 12001 - Noise types and definitions
• ISO 4871 - Declaration and verification of emission sound pressure levels
• ISO/TR 11690‑3 - Calculation of sound pressure levels in a workroom

EN ISO 11204:2010 is a practical, in‑situ acoustic standard for reliable measurement of machinery noise with documented environmental corrections and defined accuracy grades.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2010
1DGRPHãþD
SIST EN ISO 11204:2009
$NXVWLND(PLVLMDKUXSDQDSUDYLQRSUHPH0HUMHQMHHPLVLMVNHUDYQL]YRþQHJD
WODNDQDGHORYQHPPHVWXLQQDGUXJLKRSUHGHOMHQLKPHVWLK]XSRUDERQDWDQþQLK
SRSUDYNRY]DUDGLRNROMD,62
Acoustics - Noise emitted by machinery and equipment - Determination of emission
sound pressure levels at a work station and at other specified positions applying
accurate environmental corrections (ISO 11204:2010)
Akustik - Geräuschabstrahlung von Maschinen und Geräten - Messung von Emissions-
Schalldruckpegeln am Arbeitsplatz und an anderen festgelegten Orten unter Anwendung
exakter Umgebungskorrekturen (ISO 11204:2010)
Acoustique - Bruit émis par les machines et équipements - Mesurage des niveaux de
pression acoustique d'émission au poste de travail et en d'autres positions spécifiées en
appliquant des corrections d'environnement exactes (ISO 11204:2010)
Ta slovenski standard je istoveten z: EN ISO 11204:2010
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 11204
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2010
ICS 17.140.20 Supersedes EN ISO 11204:2009
English Version
Acoustics - Noise emitted by machinery and equipment -
Determination of emission sound pressure levels at a work
station and at other specified positions applying accurate
environmental corrections (ISO 11204:2010)
Acoustique - Bruit émis par les machines et équipements - Akustik - Geräuschabstrahlung von Maschinen und
Détermination des niveaux de pression acoustique Geräten - Bestimmung von Emissions-Schalldruckpegeln
d'émission au poste de travail et en d'autres positions am Arbeitsplatz und an anderen festgelegten Orten unter
spécifiées en appliquant des corrections d'environnement Anwendung exakter Umgebungskorrekturen (ISO
exactes (ISO 11204:2010) 11204:2010)
This European Standard was approved by CEN on 22 April 2010.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11204:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC .4

Foreword
This document (EN ISO 11204:2010) has been prepared by Technical Committee ISO/TC 43 “Acoustics” in
collaboration with Technical Committee CEN/TC 211 “Acoustics” the secretariat of which is held by DS.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by November 2010, and conflicting national standards shall be withdrawn
at the latest by November 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11204:2009.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive.
For relationship with EU Directive, see informative Annex ZA, which is an integral part of this document.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 11204:2010 has been approved by CEN as a EN ISO 11204:2010 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to provide a means of conforming to Essential Requirements of the
New Approach Directive 2006/42/EC on machinery.
Once this standard is cited in the Official Journal of the European Union under that Directive and has been
implemented as a national standard in at least one Member State, compliance with the normative clauses of
this standard confers, within the limits of the scope of this standard, a presumption of conformity with the
corresponding Essential Requirements of that Directive and associated EFTA regulations.
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling within
the scope of this standard.
INTERNATIONAL ISO
STANDARD 11204
Second edition
2010-05-15
Acoustics — Noise emitted by machinery
and equipment — Determination of
emission sound pressure levels at a work
station and at other specified positions
applying accurate environmental
corrections
Acoustique — Bruit émis par les machines et équipements —
Détermination des niveaux de pression acoustique d'émission au poste
de travail et en d'autres positions spécifiées en appliquant des
corrections d'environnement exactes

Reference number
ISO 11204:2010(E)
©
ISO 2010
ISO 11204:2010(E)
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ii © ISO 2010 – All rights reserved

ISO 11204:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.2
3 Terms and definitions .3
4 Instrumentation .7
5 Test environment.8
6 Measured quantities.10
7 Quantities to be determined.11
8 Mounting and operation of source under test.11
9 Microphone positions .13
10 Measurements .15
11 Measurement uncertainty.17
12 Information to be recorded.20
13 Test report.21
Annex A (normative) Environmental correction for a work station — Determination of the local
environmental correction, K .23
Annex B (normative) Criteria for background noise for measurements in frequency bands .26
Annex C (informative) Guidance on the development of information on measurement uncertainty .28
Annex D (informative) Principles of the methodology .34
Annex E (informative) Example of a test table.35
Bibliography.36

ISO 11204:2010(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11204 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition (ISO 11204:1995), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 11204:1995/Cor.1:1997.
iv © ISO 2010 – All rights reserved

ISO 11204:2010(E)
Introduction
This International Standard specifies a method for determining the emission sound pressure levels at a work
station and at other well defined positions, in the vicinity of a machine or piece of equipment, in situ. It is one
[15] [19]
of a series (ISO 11200 to ISO 11205 ) which specifies various methods for determining the emission
sound pressure level at a work station and at other specified positions of a machine or equipment.
[15]
ISO 11200 gives guidance on the choice of the method to be used to determine the emission sound
pressure levels of machinery and equipment.
[16]
The method specified in this International Standard differs from those of ISO 11201 in determining and
[17]
applying a local environmental correction. It differs from ISO 11202 by using an exact measurement of
sound pressure levels on a reference measurement surface to determine the directivity of the sound radiation
of the machine under test. The acoustical properties of the room have to be determined to qualify the test
environment and to determine a correction for local environmental influences applied to the measured sound
pressure levels. With the method specified in this International Standard, results of accuracy grade 2
(engineering grade) or accuracy grade 3 (survey grade) are obtained.
The method specified in this International Standard is generally applicable in situ. No assumptions about the
directivity of the radiation or the source location are necessary, because this directivity is determined
measuring the sound pressure levels on an enveloping surface. The grade of accuracy of the procedure with
existing conditions can be qualified as engineering or survey.
In general, the emission sound pressure levels are less than or equal to those that occur when the machine is
operating in its normal surroundings. This is because the sound pressure levels are determined by excluding
the effects of background noise, as well as the effects of reflections other than those from the reflecting plane
on which the machine under test is placed. For determination or calculation of the sound pressure level at the
operator's position with the machine operating in a room, both sound power level and sound pressure level
are required (as well as information on the room properties or reflections and noise from other sound sources
or machines). A method of calculating the sound pressure levels in the vicinity of a machine operating alone in
[20]
a workroom is given in ISO/TR 11690-3 . Commonly observed differences are 1 dB to 5 dB, but in extreme
cases the difference may be even greater.

INTERNATIONAL STANDARD ISO 11204:2010(E)

Acoustics — Noise emitted by machinery and equipment —
Determination of emission sound pressure levels at a work
station and at other specified positions applying accurate
environmental corrections
1 Scope
1.1 General
This International Standard specifies a method for determining the emission sound pressure levels of
machinery or equipment, at a work station and at other specified positions nearby, in any environment which
meets certain qualification requirements. A work station is occupied by an operator and may be located in
open space, in the room where the source under test operates, in a cab fixed to the source under test, or in an
enclosure remote from the source under test. One or more specified positions may be located in the vicinity of
a work station, or in the vicinity of an attended or unattended machine. Such positions are sometimes referred
to as bystander positions.
Emission sound pressure levels are determined as A-weighted levels. Additionally, levels in frequency bands
and C-weighted peak emission sound pressure levels can be determined in accordance with this International
Standard, if required.
[15] [19] [15]
NOTE 1 The contents of the series ISO 11200 to ISO 11205 are summarized in ISO 11200 .
A method is given for determining a local environmental correction (subject to a specified limiting maximum
value) to be applied to the measured sound pressure levels to exclude the effects of reflections from reflecting
surfaces other than the plane on which the source under test is placed. This correction is based upon the
mean sound pressure level on a measurement surface, the sound pressure level measured at a specified
position, and either an environmental correction or the equivalent absorption area of the test room.
With the method specified in this International Standard, results of accuracy grade 2 (engineering grade) or
accuracy grade 3 (survey grade) are obtained. Corrections are applied for background noise and, as
described above, for the acoustic environment. Instructions are given for the mounting and operation of the
source under test and for the choice of microphone positions for the work station and for other specified
positions. One purpose of the measurements is to permit comparison of the performance of different units of a
given family of machines, under defined environmental conditions and standardized mounting and operating
conditions.
NOTE 2 The data obtained can also be used for the declaration and verification of emission sound pressure levels as
[9]
specified in ISO 4871 .
1.2 Types of noise and noise sources
The method specified in this International Standard is suitable for all types of noise (steady, non-steady,
fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001.
The method specified in this International Standard is applicable to all types and sizes of noise sources.
NOTE Throughout this International Standard the words “machine” and “source under test” are used to represent
either a machine or a piece of equipment.
ISO 11204:2010(E)
1.3 Test environment
The type of test environment influences the accuracy of the determination of emission sound pressure levels.
This International Standard is applicable to an indoor or outdoor environment with one or more reflecting
planes present, meeting specified requirements. These requirements on the room are less strict than those of
[16]
ISO 11201 , in particular regarding the acoustical quality of the environment.
1.4 Work station and other specified positions
This International Standard is applicable to work stations and other specified positions where emission sound
pressure levels are to be determined.
Appropriate positions where measurements may be made include the following:
a) work station located in the vicinity of the source under test; this is the case for many industrial machines
and domestic appliances;
b) work station within a cab which is an integral part of the source under test; this is the case for many
industrial trucks and earth-moving machines;
c) work station within a partial or total enclosure (or behind a screen) supplied by the manufacturer as an
integral part of the source under test;
d) work station partially or totally enclosed by the source under test — this situation may be encountered
with some large industrial machines;
e) bystander positions occupied by individuals not responsible for the operation of the source under test, but
who may be in its immediate vicinity, either occasionally or continuously;
f) other specified positions, not necessarily work stations or bystander positions.
The work station may also lie on a specified path along which an operator moves (see 9.4).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3744, Acoustics — Determination of sound power levels of noise sources using sound pressure —
Engineering method in an essentially free field over a reflecting plane
ISO 3746, Acoustics — Determination of sound power levels of noise sources using sound pressure —
Survey method using an enveloping measurement surface over a reflecting plane
ISO 5725 (all parts), Accuracy (trueness and precision) of measurement methods and results
ISO 12001, Acoustics — Noise emitted by machinery and equipment — Rules for the drafting and
presentation of a noise test code
IEC 60942:2003, Electroacoustics — Sound calibrators
IEC 61260:1995, Electroacoustics — Octave-band and fractional-octave-band filters (amended by
IEC 61260/Amd.1:2001)
IEC 61672-1:2002, Electroacoustics — Sound level meters — Part 1: Specifications
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
2 © ISO 2010 – All rights reserved

ISO 11204:2010(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. More detailed definitions can be
found in noise test codes for specific types of machines.
3.1
emission
〈acoustics〉 airborne sound radiated by a well-defined noise source (e.g. the machine under test)
NOTE Noise emission descriptors can be incorporated into a product label and/or product specification. The basic
noise emission descriptors are the sound power level of the source itself and the emission sound pressure levels at a work
station and/or at other specified positions (if any) in the vicinity of the source.
3.2
emission sound pressure
p
sound pressure, at a work station or another specified position near a noise source, when the source is in
operation under specified operating and mounting conditions on a reflecting plane surface, excluding the
effects of background noise as well as the effects of reflections other than those from the plane or planes
permitted for the purpose of the test
NOTE Emission sound pressure is expressed in pascals.
3.3
emission sound pressure level
L
p
ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure, p, to the
square of a reference value, p , expressed in decibels
p
L = 10lg dB (1)
p
p
where the reference value, p , is 20 µPa
NOTE The emission sound pressure level is determined at a work station or another specified position in accordance
with either a noise test code for a specific family of machines or, if no noise test code exists, one of the standards of the
[15] [19]
series ISO 11200 to ISO 11205 .
3.4
time-averaged emission sound pressure level
L
p,T
ten times the logarithm to the base 10 of the ratio of the time average of the square of the emission sound
pressure, p, during a stated time interval of duration, T (starting at t and ending at t ), to the square of a
1 2
reference value, p , expressed in decibels
t
⎡⎤2
⎢⎥
pt()dt
∫
⎢⎥T
t
⎢⎥1
L = 10lg dB (2)
pT,
⎢⎥
p
⎢⎥
⎢⎥
⎢⎥
⎣⎦
where the reference value, p , is 20 µPa
NOTE 1 For simplicity of notation, the subscript T is omitted throughout the following text.
ISO 11204:2010(E)
NOTE 2 If specific frequency and time weightings as specified in IEC 61672-1 and/or specific frequency bands are
applied, this is indicated by appropriate subscripts; e.g. L denotes the A-weighted emission sound pressure level.
pA
NOTE 3 Equation (2) is equivalent to that for the environmental noise descriptor “equivalent continuous sound pressure
[1]
level” (ISO 1996-1 ). However, the emission quantity defined above is used to characterize the noise emitted by a source
under test and assumes that standardized measurement and operating conditions as well as a controlled acoustical
environment are used for the measurements.
3.5
peak emission sound pressure
p
peak
greatest absolute emission sound pressure during a stated time interval
NOTE 1 Peak sound pressure is expressed in pascals.
NOTE 2 A peak sound pressure may arise from a positive or negative sound pressure.
3.6
peak emission sound pressure level
L
p,peak
ten times the logarithm to the base 10 of the ratio of the square of the peak emission sound pressure, p , to
peak
the square of a reference value, p , expressed in decibels
p
peak
L = 10lg dB (3)
p,peak
p
where the reference value, p , is 20 µPa
NOTE The peak emission sound pressure level is usually C-weighted and denoted by L .
pC,peak
3.7
single event emission sound pressure level
L
E
ten times the logarithm to the base 10 of the ratio of the integral of the square of the emission sound pressure,
p, of an isolated single sound event (burst of sound or transient sound) of specified duration T (or specified
measurement time interval T = t − t covering the single event) to the square of a reference value, p ,
2 1 0
normalized to reference time interval T = 1 s, expressed in decibels
t
⎡⎤
1(pt)
⎢⎥
Lt= 10lg d dB
E
∫
⎢⎥
T
p
t
⎢⎥ (4)
⎣⎦1
T
=+L 10lg dB
p,T
T
NOTE Equation (4) is equivalent to that for the environmental noise descriptor “sound exposure level”
[21]
(ISO/TR 25417:2007 , 2.7). However, the emission quantity defined above is used to characterize the noise emitted by a
source under test and assumes that standardized measurement, mounting, and operating conditions as well as a
controlled acoustical environment are used for the measurements.
3.8
acoustic free field over a reflecting plane
sound field in a homogeneous, isotropic medium in the half space above an infinite reflecting plane, in the
absence of any other obstacles
4 © ISO 2010 – All rights reserved

ISO 11204:2010(E)
3.9
frequency range of interest
for general purposes, the frequency range of octave bands with nominal mid-band frequencies from 125 Hz to
8 000 Hz or the one-third octave bands with nominal mid-band frequencies from 100 Hz to 10 000 Hz
[10]
NOTE 1 Adapted from ISO 6926:1999 , 3.10.
NOTE 2 For special purposes, the frequency range may be extended or reduced, provided that the test environment
and instrument specifications are satisfactory for use over the modified frequency range. Changes to the frequency range
of interest should be made clear in the test report. For sources which emit sound at predominantly high or low frequencies,
the frequency range of interest should be extended to include these frequencies.
3.10
work station
operator's position
position in the vicinity of the machine under test which is intended for the operator
3.11
operator
individual whose work station is in the vicinity of a machine and who is performing a work task associated with
that machine
3.12
specified position
position defined in relation to a machine, including, but not limited to, an operator's position
NOTE 1 The position can be a single, fixed point, or a combination of points along a path or on a surface located at a
specified distance from the machine, as described in the relevant noise test code, if one exists.
NOTE 2 Positions located in the vicinity of a work station, or in the vicinity of an unattended machine, may be identified
as “bystander positions”.
NOTE 3 Throughout the text of this International Standard, the word “work station” applies to possible specified
positions listed in 1.4.
3.13
operational period
interval of time during which a specified process is accomplished by the source under test
EXAMPLE For a dishwasher, when washing or rinsing or drying.
3.14
operational cycle
specific sequence of operational periods occurring while the source under test performs a complete work
cycle, where each operational period is associated with a specific process that may occur only once, or may
be repeated, during the operational cycle
EXAMPLE For a dishwasher, when washing and rinsing and drying.
3.15
measurement time interval
portion or a multiple of an operational period or operational cycle of the source under test, for which the time-
averaged emission sound pressure level is determined or over which the maximum emission sound pressure
level is sought
3.16
time history
continuous recording of the emission sound pressure level, as a function of time, which is obtained during one
or more operational periods of an operational cycle
ISO 11204:2010(E)
3.17
background noise
noise from all sources other than the source under test
NOTE Background noise can include contributions from airborne sound, structure-borne vibration, and electrical
noise in instrumentation.
3.18
background noise correction
K
correction applied to the measured sound pressure levels to account for the influence of background noise
NOTE 1 Background noise correction is expressed in decibels.
NOTE 2 Background noise correction is frequency dependent. In the case of A-weighting, the correction, K , is
1A
determined from A-weighted measured values.
3.19
reference box
hypothetical rectangular parallelepiped terminating on the reflecting plane(s) on which the noise source under
test is located, that just encloses the source including all the significant sound-radiating components and any
test table on which the source may be mounted
3.20
reference measurement surface
S
M
hypothetical surface defined by a rectangular parallelepiped enveloping the source under test, terminating on
the reflecting plane(s) on which the source is located, and having sides parallel to those of the reference box
with each side spaced at equal distance from the corresponding side of the reference box
NOTE 1 The “equal distance” is preferably of 1 m.
NOTE 2 The work station does not have to be located on the reference measurement surface.
3.21
environmental correction
K
term to account for the influence of reflected sound on the mean sound pressure level on the reference
measurement surface, expressed in decibels
NOTE 1 K is frequency dependent and can be determined in accordance with ISO 3744 or ISO 3746. In the case of
A-weighting, it is denoted K .
2A
NOTE 2 For the purposes of this International Standard, the environmental correction K is only used as an indicator to
qualify the environment and is determined for the reference measurement surface.
6 © ISO 2010 – All rights reserved

ISO 11204:2010(E)
3.22
work station directivity index
D
I,op
measure of the extent to which a source under test radiates sound in the direction of the work station
(operator's position), relative to the mean sound radiation over the reference measurement surface,
expressed in decibels
D =−LL (5)
I,op pp
where
L is the emission sound pressure level;
p
L is the surface sound pressure level (in accordance with ISO 3744) on the reference measurement
p
surface
NOTE These levels are determined in an essentially free field over a reflecting plane and have been corrected for
background noise and for environmental influences, if relevant.
3.23
apparent work station directivity index
*
D
I op
** *
D =−LL (6)
I op pp
where
*
L is the sound pressure level measured at the work station, corrected for background noise, but not
p
for the influence of the environment;
*
L is the sound pressure level averaged over the reference measurement surface, corrected for
p
background noise, but not for the influence of the environment
3.24
local environmental correction
K
correction applied to the measured sound pressure levels at the work station to account for the influence of
reflected sound, expressed in decibels
NOTE 1 In the case of A-weighting, it is denoted K .
3A
NOTE 2 The local environmental correction is frequency dependent.
4 Instrumentation
4.1 General
The instrumentation system, including the microphones, cables and windscreen, if used, shall meet the
requirements of IEC 61672-1:2002, class 1, and the filters, if relevant, shall meet the requirements of
IEC 61260:1995, class 1.
A class 2 sound level meter can be used but the measurement result is then automatically of accuracy
grade 3.
ISO 11204:2010(E)
4.2 Calibration
Before and after each series of measurements, a sound calibrator meeting the requirements of
IEC 60942:2003, class 1, shall be applied to each microphone to verify the calibration of the entire measuring
system at one or more frequencies over the frequency range of interest. Without any further adjustment, the
difference between the readings at each end of the series of measurements shall be less than or equal to
0,5 dB. If the difference exceeds 0,5 dB, the results of the series of measurements shall be discarded.
The sound calibrator shall be calibrated, and the compliance of the instrumentation system with the
requirements of IEC 61672-1 shall be verified at intervals in a laboratory making calibrations traceable to
appropriate standards.
Unless national regulations dictate otherwise, the sound calibrator should be calibrated annually, and the
compliance of the instrumentation system with the requirements of IEC 61672-1 should be verified at intervals
not exceeding 2 years.
5 Test environment
5.1 General
Any environment which meets the qualification requirements of 5.2, 5.4, 5.6 and Annex A is suitable for
measurements in accordance with this International Standard.
5.2 Criterion for the adequacy of the test environment
For this International Standard, the environmental correction, K , determined in accordance with ISO 3744 or
2A
ISO 3746, shall not exceed 7 dB. Further requirements on the test environment influencing the local
environmental correction, K (see 5.6), are specified in Annex A.
3A
[19]
If K > 7 dB, either the acoustical quality of the environment requires improvement or ISO 11205 can be
2A
used.
5.3 Enclosed work station positions
When the operator is located in an enclosed cab or in an enclosure remote from the source under test, the
cab or enclosure is regarded as an integral part of the source under test and, consequently, sound reflections
inside the cab or enclosure are considered contributions to the emission sound pressure level.
During noise emission measurements, doors and windows of the cabin or enclosure shall be open or closed
as specified in the relevant noise test code, if one exists.
The local environmental correction, K , is determined as described in A.2 and A.3 using the apparent work
*
station directivity index, D . With the work station position in an enclosure this apparent work station
I op
* *
directivity index, D , is determined based on Equation (6), but with L measured at a position outside the
I op p
enclosure at a comparable distance (distance from the source under test to the centre of the cabin) from the
source under test. This is necessary in all cases when the noise inside the cabin is due to airborne sound
transmission into the cabin enclosure, i.e. the noise level at the ears of the operator in the cabin is due to the
sound field outside the cabin. If levels inside the cabin are strongly dependent on the microphone position, at
least four measurement points shall be used to sample the sound field in the relevant part of the cabin. These
positions shall be reported according to 12.6.
8 © ISO 2010 – All rights reserved

ISO 11204:2010(E)
5.4 Criteria for background noise
5.4.1 General
At the microphone position(s), the background noise (including wind noise at the microphone) measured as
A-weighted sound pressure level or (if results in frequency bands are required) in each of the frequency bands
of interest shall be at least 6 dB for accuracy grade 2 (engineering) or 3 dB for accuracy grade 3 (survey)
below the uncorrected level of the source under test measured in the presence of this background noise.
If the above 6 dB criterion or the 3 dB criterion is not satisfied, data may still be taken and reported, but the
accuracy of the results may be reduced. In this case, the report shall clearly state that the background noise
requirements of this International Standard have not been met, and (if frequency band data are reported) shall
identify the particular frequency bands that do not meet the criteria. Furthermore, the report shall not state or
imply that the measurements have been made in “full conformity” with this International Standard.
For measurements in frequency bands, further criteria for background noise are given in Annex B.
5.4.2 Corrections for background noise
The measured sound pressure levels (A-weighted or in frequency bands) shall be subject to a correction for
the presence of background noise, K , calculated according to Equation (7):
−∆0,1 L
K =−10 lg(1−10 ) dB (7)
where ∆L is the difference between the sound pressure levels measured (A-weighted or in frequency bands),
at the work station, with the source under test in operation and turned off, respectively.
For the purposes of this International Standard, if ∆L > 15 dB, assume K = 0.
For accuracy grade 2, if ∆L < 6 dB for one or more octave or one-third-octave frequency bands, the accuracy
of the result(s) may be reduced and the value of K to be applied in the case of these bands is 1,3 dB, which
is the value for ∆L = 6 dB.
For accuracy grade 3, if ∆L < 3 dB for one or more octave or one-third-octave frequency bands, the accuracy
of the result(s) may be reduced and the value of K to be applied is 3 dB, which is the value for ∆L = 3 dB.
In both cases, it shall be clearly stated in the text of the report, as well as in graphs or tables of results, that
the data in such bands represent upper bounds to the emission sound pressure level of the noise source
under test for the relevant grade of accuracy. If the background noise requirements for accuracy grade 2 are
not met, it is still possible that the requirements for accuracy grade 3 are fulfilled. In this case, the final result
can be reported claiming for accuracy grade 3 in accordance with this International Standard (if all other
requirements are also fulfilled).
Determine K for each work station.
5.5 Ambient conditions during measurements
Ambient conditions may have an adverse effect on the microphone used for the measurements. Such
conditions (e.g. strong electric or magnetic fields, wind, high or low temperatures, or impingement of air
discharge from the source under test) shall be avoided by proper selection or positioning of the microphone.
ISO 11204:2010(E)
At altitudes less than or equal to 500 m above sea level and in temperature range from −20 °C to 40 °C no
normalization to reference meteorological conditions is required. At altitudes greater than 500 m (accuracy
grade 2) or greater than 800 m (accuracy grade 3) above sea level or temperatures outside the above range
the measured sound pressure level, L , in decibels, shall be normalized to the reference meteorological
p
conditions
p = 1,013 25 × 10 Pa
amb, 0
Θ = 296 K
by using Equation (8) to obtain the emission sound pressure level for the reference meteorological conditions,
L , in decibels
p, 0
p
Θ
amb
LL=− 20 lg dB+ 20 lg dB (8)
pp,0
p Θ
amb,0 0
where
p is the ambient pressure, in pascals, at the time and place of the test;
amb
Θ is the air temperature, in kelvins, at the time and place of the test.
5.6 Local environmental correction and grade of accuracy
Annex A describes a procedure for determining the magnitude of the local environmental correction, K , to
account for the influence of reflected sound on the emission sound pressure level at the work station(s).
The method given in Annex A requires data for a number of measurement positions around the source under
test, as well as information about the acoustical properties of the test room. Measurements are only in full
accordance with this International Standard if K does not exceed 7 dB. For results of accuracy grade 2, K
3A 3A
shall be less than or equal to 4 dB; for results of accuracy grade 3, K shall be less than or equal to 7 dB.
3A
NOTE If the limit value of 7 dB is exceeded, the accuracy of the result is reduced. The result may, however, be
reported and may be useful for determining an upper boundary for the emission sound pressure level at the work station.
6 Measured quantities
The basic quantities to be measured at each work station over the specified operational periods or operational
cycle of the source under test are:
′
⎯ the A-weighted sound pressure level, L (the prime indicates measured values);
pA
⎯ the C-weighted peak sound pressure level, L , if required.
pC, peak
Sound pressure levels using other frequency weightings or in octave or one-third-octave frequency bands, as
well as other entities relating to the time-history of the noise emission (impulsiveness, sound pressure level as
a function of time, etc.) may also be measured, as required, e.g. for the design of low-noise machines.
10 © ISO 2010 – All rights reserved

ISO 11204:2010(E)
7 Quantities to be determined
The quantity to be determined is the A-weighted emission sound pressure level. Additionally, emission sound
pressure levels in frequency bands may be determined.
In order to obtain emission sound pressure levels at the work station(s), both background noise corrections,
K , and local environmental corrections, K , shall be applied to measured sound pressure levels, except peak
1 3
sound pressure levels, L , for which no corrections are permitted.
pC, peak
Corrections K and K to be considered are those relevant to the frequency weighting or frequency bands for
1 3
which emission sound pressure levels have been determined. For frequency bands and A-weighting,
respectively:
L =−LK′ −K
pp 13
LL=−′ K−K (9)
ppAA 1A 3A
where the prime indicates measured values; no prime indicates emission values.
If a work station (within or outside an
...