SIST EN ISO 3745:2012/A1:2017

Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms - Amendment 1 (ISO 3745:2012/Amd 1:2017)

Akustik - Bestimmung der Schallleistungs- und Schallenergiepegel von Geräuschquellen aus Schalldruckmessungen - Verfahren der Genauigkeitsklasse 1 für reflexionsarme Räume und Halbräume - Änderung 1 (ISO 3745:2012/Amd 1:2017)

Acoustique - Détermination des niveaux de puissance acoustique et des niveaux d'énergie acoustique émis par les sources de bruit à partir de la pression acoustique - Méthodes de laboratoire pour les salles anéchoïques et les salles semi-anéchoïques - Amendement 1 (ISO 3745:2012/Amd 1:2017)

Akustika - Ugotavljanje ravni zvočnih moči in ravni zvočne energije virov hrupa z zvočnim tlakom - Precizijska metoda za gluhe in polgluhe prostore - Dopolnilo A1 (ISO 3745:2012/Amd 1:2017)

General Information

• Status: Published
• Public Enquiry End Date: 29-Apr-2015
• Publication Date: 15-Aug-2017
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• ICS: 91.120.20 - Acoustics in building. Sound insulation
• Technical Committee: AKU - Acoustics
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Aug-2017
• Due Date: 07-Oct-2017
• Completion Date: 16-Aug-2017
• 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)
• 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: EN ISO 3745:2012/A1:2017 - Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms - Amendment 1 (ISO 3745:2012/Amd 1:2017)

Relations

• Amends: SIST EN ISO 3745:2012 - Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms (ISO 3745:2012)
• Effective Date: 01-Sep-2017

Overview

EN ISO 3745:2012/A1:2017 (CEN) is an amendment to ISO 3745:2012 that updates precision laboratory methods for determining sound power levels and sound energy levels of noise sources from sound pressure measurements in anechoic and hemi‑anechoic rooms. The amendment aligns room‑qualification procedures with ISO 26101:2017, revises Annex A (qualification of test rooms), and clarifies practical measurement requirements for conformity with machine‑noise and related EU directives.

Key topics and requirements

• Scope: Precision methods for measurements in anechoic and hemi‑anechoic rooms (laboratory conditions).
• Normative reference added: ISO 26101:2017 (qualification of free‑field environments).
• Room qualification (Annex A replacement) follows ISO 26101 procedures and includes:
  • Default use of discrete‑frequency (e.g., pure tone or narrowband) qualification unless source is known to be broadband.
  • Maximum allowable deviations from the inverse square law (measured vs. theoretical):
    • Anechoic rooms: ≤ 630 Hz: ±1.5 dB; 800–5 000 Hz: ±1.0 dB; ≥ 6 300 Hz: ±1.5 dB
    • Hemi‑anechoic rooms: ≤ 630 Hz: ±2.5 dB; 800–5 000 Hz: ±2.0 dB; ≥ 6 300 Hz: ±3.0 dB
  • Frequency range to be qualified: at least 100 Hz to 10 000 Hz (rules for band selection and evaluation specified).
  • Mathematical origin for inverse square evaluation must lie within the physical volume of the test source.
  • Requirements for microphone traverse paths and spatial resolution updated (see ISO 26101).
  • Reflecting plane in hemi‑anechoic rooms: sound absorption coefficient ≤ 0.06 over the qualified range.
  • Qualification checks recommended after absorber modification and periodically (≤ 5 years).
• Annex B provides an alternative, source‑specific qualification method (not for general room qualification).
• Notes on relaxed background noise and test source stability limits consistent with ISO 26101.

Applications and users

This standard is used by:

• Acoustic test laboratories certifying anechoic/hemi‑anechoic rooms
• Manufacturers of machinery, appliances and components performing sound power/energy measurements
• Product compliance engineers demonstrating conformity with Directive 2006/42/EC (machinery)
• Acoustic consultants, R&D teams, and quality assurance groups conducting precision noise testing

Practical uses include sound power certification, R&D acoustic characterization, product noise labeling, and regulatory conformity testing.

Related standards

• ISO 3745:2012 (base document)
• ISO 26101:2017 (qualification of free‑field environments) - now a normative reference incorporated by this amendment

Keywords: EN ISO 3745:2012/A1:2017, ISO 3745 amendment, anechoic room qualification, hemi‑anechoic, sound power level, sound energy level, sound pressure measurement, ISO 26101.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2017
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Acoustics - Determination of sound power levels and sound energy levels of noise
sources using sound pressure - Precision methods for anechoic rooms and hemi-
anechoic rooms - Amendment 1 (ISO 3745:2012/Amd 1:2017)
Akustik - Bestimmung der Schallleistungs- und Schallenergiepegel von Geräuschquellen
aus Schalldruckmessungen - Verfahren der Genauigkeitsklasse 1 für reflexionsarme
Räume und Halbräume - Änderung 1 (ISO 3745:2012/Amd 1:2017)
Acoustique - Détermination des niveaux de puissance acoustique et des niveaux
d'énergie acoustique émis par les sources de bruit à partir de la pression acoustique -
Méthodes de laboratoire pour les salles anéchoïques et les salles semi-anéchoïques -
Amendement 1 (ISO 3745:2012/Amd 1:2017)
Ta slovenski standard je istoveten z: EN ISO 3745:2012/A1:2017
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
91.120.20 $NXVWLNDYVWDYEDK=YRþQD Acoustics in building. Sound
L]RODFLMD insulation
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 3745:2012/A1
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2017
EUROPÄISCHE NORM
ICS 17.140.01
English Version
Acoustics - Determination of sound power levels and
sound energy levels of noise sources using sound pressure
- Precision methods for anechoic rooms and hemi-
anechoic rooms - Amendment 1 (ISO 3745:2012/Amd
1:2017)
Acoustique - Détermination des niveaux de puissance Akustik - Bestimmung der Schallleistungs- und
acoustique et des niveaux d'énergie acoustique émis Schallenergiepegel von Geräuschquellen aus
par les sources de bruit à partir de la pression Schalldruckmessungen - Verfahren der
acoustique - Méthodes de laboratoire pour les salles Genauigkeitsklasse 1 für reflexionsarme Räume und
anéchoïques et les salles semi-anéchoïques - Halbräume - Änderung 1 (ISO 3745:2012/Amd
Amendement 1 (ISO 3745:2012/Amd 1:2017) 1:2017)
This amendment A1 modifies the European Standard EN ISO 3745:2012; it was approved by CEN on 20 March 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This amendment 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-CENELEC 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3745:2012/A1:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 4

European foreword
This document (EN ISO 3745:2012/A1:2017) 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 DIN.
This Amendment to the European Standard EN ISO 3745:2012 shall be given the status of a national
standard, either by publication of an identical text or by endorsement, at the latest by November 2017,
and conflicting national standards shall be withdrawn at the latest by November 2017.
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 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(s).
For relationship with EU Directive(s), 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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 3745:2012/Amd 1:2017 has been approved by CEN as EN ISO 3745:2012/A1:2017
without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered
This European Standard has been prepared under a Commission’s standardization request M/396
(Machinery) to provide one voluntary means of conforming to essential requirements of 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).
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZA.1 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.
Table ZA.1 — Correspondence between this European Standard and Directive 2006/42/EC
Essential Requirements of Clause(s)/sub-clause(s) of Remarks/Notes
Directive this EN
1.7.4.2 u) All clauses
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
Standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
INTERNATIONAL ISO
STANDARD 3745
Third edition
2012-03-15
AMENDMENT 1
2017-04
Acoustics — Determination of sound
power levels and sound energy levels
of noise sources using sound pressure
— Precision methods for anechoic
rooms and hemi-anechoic rooms
AMENDMENT 1
Acoustique — Détermination des niveaux de puissance acoustique et
des niveaux d’énergie acoustique émis par les sources de bruit à partir
de la pression acoustique — Méthodes de laboratoire pour les salles
anéchoïques et les salles semi-anéchoïques
AMENDEMENT 1
Reference number
ISO 3745:2012/Amd.1:2017(E)
©
ISO 2017
ISO 3745:2012/Amd.1:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
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ii © ISO 2017 – All rights reserved

ISO 3745:2012/Amd.1:2017(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
ISO 3745:2012/Amd.1:2017(E)
Acoustics — Determination of sound power levels and
sound energy levels of noise sources using sound pressure
— Precision methods for anechoic rooms and hemi-
anechoic rooms
AMENDMENT 1
Page 1, Normative references
Add the following reference:
ISO 26101:2017, Acoustics — Test methods for the qualification of free-field environments

Page 29, Annex A
Replace Annex A with the following:
Annex A
(normative)
General procedures for qualification of anechoic and hemi-anechoic rooms
A.1 General
The performance of an anechoic or hemi-anechoic room is tested by comparing the spatial decrease of
sound pressure emitted from a test sound source with the decrease of sound pressure that would occur
in an ideal free sound field. The evaluation of this performance is based on the procedures outlined in
ISO 26101.
This annex contains the qualification criteria and test parameters which are required to qualify test
rooms to the requirements of this document. To conform to this document, when no specific criteria are
given, the requirements appropriate for sound power measurements in ISO 26101 shall be met.
A check of the room performance is recommended after modification of the room absorbers and
periodically at intervals not exceeding 5 years.
The following is a comparison of this annex with ISO 26101 and previous versions of this annex:
a) As in the previous version (ISO 3745:2012, Annex A), this annex requires that test rooms are
qualified using discrete-frequency (e.g. pure tone) measurements unless it is known that the
specific noise source under test radiates only broadband noise (see Note below).
b) Consistent with the wording in ISO 26101, this annex defines methods for “discrete-frequency”
and “broadband” qualification of test rooms. Discrete-frequency qualification is essentially
identical to the pure tone qualification used in the previous versions of this annex. In both cases,
only one pure tone is analysed in each frequency band in Table A.1. The wording change from
“pure tone qualification” is consistent with, for example, common fast Fourier transform methods
such as the use of pseudo random noise and narrow bandwidth analysis; see Reference [37] and
ISO 26101:2017, 5.1.4.1, 5.1.4.2.
c) For the purposes of this document, this annex does not require an evaluation of the position of
the acoustic centre. In this annex
...