SIST EN ISO 8528-10:2023

SLOVENSKI STANDARD
01-marec-2023
Sestavi tokovnih generatorjev, ki jih poganja batni stroj z notranjim zgorevanjem -
10. del: Meritev hrupa v zraku (ISO 8528-10:2022)
Reciprocating internal combustion engine driven alternating current generating sets -
Part 10: Measurement of airborne noise (ISO 8528-10:2022)
Stromerzeugungsaggregate mit Hubkolben-Verbrennungsmotor - Teil 10: Messung von
Luftschall mit der Hüllflächenmethode (ISO 8528-10:2022)
Groupes électrogènes à courant alternatif entraînés par moteurs alternatifs à combustion
interne - Partie 10: Mesurage du bruit aérien (ISO 8528-10:2022)
Ta slovenski standard je istoveten z: EN ISO 8528-10:2022
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
27.020 Motorji z notranjim Internal combustion engines
zgorevanjem
29.160.40 Električni agregati Generating sets
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 8528-10
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 17.140.20; 27.020; 29.160.40
English Version
Reciprocating internal combustion engine driven
alternating current generating sets - Part 10: Measurement
of airborne noise (ISO 8528-10:2022)
Groupes électrogènes à courant alternatif entraînés par Stromerzeugungsaggregate mit Hubkolben-
moteurs alternatifs à combustion interne - Partie 10: Verbrennungsmotor - Teil 10: Messung von Luftschall
Mesurage du bruit aérien (ISO 8528-10:2022) mit der Hüllflächenmethode (ISO 8528-10:2022)
This European Standard was approved by CEN on 1 October 2022.

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-CENELEC 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-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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8528-10:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this document and the essential
requirements of Directive 2006/42/EC aimed to be covered . 4
European foreword
This document (EN ISO 8528-10:2022) has been prepared by Technical Committee ISO/TC 70 "Internal
combustion engines" in collaboration with Technical Committee CEN/TC 270 “Internal combustion
engines” the secretariat of which is held by DIN.
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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For the relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral
part of this document.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 8528-10:2022 has been approved by CEN as EN ISO 8528-10:2022 without any
modification.
Annex ZA
(informative)
Relationship between this document and the essential requirements of
Directive 2006/42/EC aimed to be covered
This document has been prepared under a Commission’s standardization request “M/396 Mandate to
CEN and CENELEC for Standardisation in the field of 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 document is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this document given in Table ZA.1 confers, within the limits of
the scope of this document, a presumption of conformity with the corresponding essential
requirements of that Directive, and associated EFTA regulations.
Table ZA.1 — Correspondence between this document and Annex I of Directive 2006/42/EC
The relevant Essential Clause(s)/subclause(s) of this Remarks/Notes
Requirements of document
Directive 2006/42/EC
1.7.4.2. (u) 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this document is
maintained in the list published in the Official Journal of the European Union. Users of this document
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 document.
INTERNATIONAL ISO
STANDARD 8528-10
Second edition
2022-10
Reciprocating internal combustion
engine driven alternating current
generating sets —
Part 10:
Measurement of airborne noise
Groupes électrogènes à courant alternatif entraînés par moteurs
alternatifs à combustion interne —
Partie 10: Mesurage du bruit aérien
Reference number
ISO 8528-10:2022(E)
ISO 8528-10:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 8528-10:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 3
5 Selection of the most appropriate method. 4
5.1 General . 4
5.2 Sound power level measurements accuracy grades . 5
5.2.1 General . 5
5.2.2 Engineering grade (grade 2). 5
5.2.3 Survey grade (grade 3) . 5
6 Measuring equipment . 6
6.1 General . 6
6.2 Calibration . 6
7 Measuring environment .6
7.1 General . 6
7.2 V erification of acoustic adequacy of test environment . 6
7.3 Criteria for background noise . 6
8 Definition of noise source and operating conditions of the generating set .6
8.1 Definition of noise source under test . 6
8.2 Location, installation of the generating set . 7
8.3 Mounting of the generating set . 7
8.4 Operation of the generating set during test . 7
9 Reference box and measurement surface . 8
9.1 Reference box. 8
9.2 Determination of the reference box in special cases . 8
9.2.1 Elevated generating set on a trailer or trolley kit . 8
9.2.2 Generating set with extended exhaust device . 8
9.2.3 Generating set with auxiliary equipment . 9
9.3 Measurement surface . 9
9.3.1 General . 9
9.3.2 Microphone orientation . 9
9.3.3 Hemispherical measurement surface . 10
9.3.4 Parallelepiped measurement surface . 10
9.3.5 Reduction in the number of microphone positions . 10
10 Measurement of sound pressure levels .10
11 Determination of the A-weighted sound power level .10
11.1 Calculation of mean-time-averaged sound pressure levels . 10
11.2 Corrections for background noise. 10
11.3 Calculation of the surface time-averaged sound pressure levels . 10
11.4 Calculation of sound power levels . 11
11.5 Calculation of apparent surface sound pressure level non-uniformity index . 11
11.6 A-weighted sound power level . 11
12 Measurement uncertainty .11
13 Guaranteed sound power level .11
13.1 General . 11
13.2 Arithmetic mean of sound power levels . 11
13.3 Expanded measurement uncertainty .12
iii
ISO 8528-10:2022(E)
13.4 Coverage factor .12
13.5 Determination of σ . 12
R0
13.6 Determination of σ . 12
omc
13.7 Determination of σ . .13
p
13.8 Calculation of the guaranteed sound power level . 13
14 Test report .13
15 Determination of the emission sound pressure level at the workstation .13
15.1 General .13
15.2 Determination of location of the workstation(s) . 13
15.3 Criteria for the adequacy of the test environment . 14
15.4 Corrections for background noise. 14
15.5 Measured quantity . 14
15.6 Calculation of A-weighted emission sound pressure level . 14
15.7 Normalizing to reference meteorological conditions . 14
15.8 Quantities to be determined .15
15.9 Operation of the generating set . 15
15.10 Microphone positions .15
15.10.1 General .15
15.10.2 Microphone position for a standing operator. 16
15.10.3 Microphone position for a bending, crouching or kneeling operator . 16
15.10.4 Microphone positions if there is no clearly identifiable operator position or
for machines without operator . 16
15.11 Measurement uncertainty . 16
15.12 Test report . 16
Annex A (normative) Application of ISO 3744:2010 for generating sets .17
Annex B (normative) Application of ISO 3746:2010 for generating sets .37
Annex C (informative) Sound intensity methods .41
Bibliography .43
iv
ISO 8528-10:2022(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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 70, Internal combustion engines, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 270, Internal combustion engines, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 8528-10:1998), which has been technically
revised.
The main changes are as follows:
— the normative references have been updated;
— the latest requirements of ISO 3744:2010 and ISO 3746:2010 have been included, respecting
ISO 12001:1996 requirements;
— the measurement surfaces have been updated;
— the definition of the reference box in special cases has been added;
— the guaranteed sound power level has been added;
— requirements concerning variable speed engine gensets, fans and lighting towers have been added;
— the requirements for welding generators have been updated;
— the determination of the emission sound pressure level at workstation has been updated.
A list of all parts in the ISO 8528 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 8528-10:2022(E)
Introduction
This document specifies noise test codes for determining the basic noise emission descriptors.
For many manufacturers of generating sets, the control of noise is a major issue that requires
effective exchange of acoustical information, in particular on noise emission. The basic noise emission
descriptors are the sound power level of the generating set itself and the emission sound pressure level
at the workstation.
In this context, the main flow of information goes from the manufacturer to the purchaser. However,
installers and users of the generating sets also desire comprehensive information about the generating
sets' ability to generate airborne sound.
Thus, measuring the basic noise emission descriptors allows the generating set manufacturer to
determine, declare and verify the noise emission values.
Therefore, the sound power level, as the major parameter to characterize machines as sound sources,
is determined by measurements. The sound power level is a major parameter because it represents an
intrinsic characteristic of generating sets as noise sources. It is useful, for example, in noise-abatement
programmes or when designing a building where the generating set is intended to be used.
The emission sound pressure level at the workstation is also measured. This enables an assessment of
the risk of exposure to the airborne sound of the operators. This assessment is essential for health and
safety reasons.
In this document, the generating sets are considered as steady noise sources as per ISO 12001:1996.
The generating sets concerned and the extent to which noise is covered are indicated in this document.
This document allows measurements to be made in many different test environments. Clause 5 can be
used as a general guideline to assist in the selection of the right noise test code. The selection mainly
depends on the test environment and the desired grade of accuracy.
This document contains two methodologies for determining the measurement uncertainty. In
Clause 12, the uncertainty U is determined by considering measurements on a single generating set.
In Clause 13, the uncertainty K is determined by considering a batch of generating sets, which can be
useful for control of production purpose.
This document is a C-type standard as stated in ISO 12001:1996. When provisions of this C-type
standard are different from those stated in A or B standards, the provisions of this C-type standard
take precedence.
vi
INTERNATIONAL STANDARD ISO 8528-10:2022(E)
Reciprocating internal combustion engine driven
alternating current generating sets —
Part 10:
Measurement of airborne noise
1 Scope
This document specifies noise test codes for determining the sound power level and the emission sound
pressure level at the workstation of reciprocating internal combustion engine driven electrical power
generating sets.
This document applies to constant and variable-speed reciprocating internal combustion (RIC) engine
driven alternating current (AC) and direct current (DC) generating sets for fixed and mobile applications
with rigid or flexible mountings. It is applicable for land and marine use, excluding generating sets used
on aircraft or to propel land vehicles and locomotives.
NOTE 1 For some specific applications (e.g. essential hospital supplies, high-rise buildings) supplementary
requirements can be necessary. The provisions of this document can be regarded as a basis.
NOTE 2 This document is referenced with regard to noise in ISO 8528-13:2016, which contains requirements
concerning the design of generating sets, verification of noise levels and information related to noise in the
operating and maintenance instructions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 3046-1:2002, Reciprocating internal combustion engines — Performance — Part 1: Declarations of
power, fuel and lubricating oil consumptions, and test methods — Additional requirements for engines for
general use
ISO 3744:2010, 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 3746:2010, Acoustics — Determination of sound power levels and sound energy levels of noise sources
using sound pressure — Survey method using an enveloping measurement surface over a reflecting plane
ISO 8528-1:2018, Reciprocating internal combustion engine driven alternating current generating sets —
Part 1: Application, ratings and performance
ISO 8528-2:2018, Reciprocating internal combustion engine driven alternating current generating sets —
Part 2: Engines
ISO 15619:2013, Reciprocating internal combustion engines — Measurement method for exhaust silencers
— Sound power level of exhaust noise and insertion loss using sound pressure and power loss ratio
IEC 60942:2017, Electroacoustics - Sound calibrators
IEC 60974-1:2021, Arc welding equipment - Part 1: Welding power sources
IEC 61260-1:2014, Electroacoustics - Octave-band and fractional-octave-band filters - Part 1: Specifications
ISO 8528-10:2022(E)
IEC 61672-1:2013, Electroacoustics – Sound level meters – Part 1: specifications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3046-1:2002, ISO 8528-1:2018
and ISO 8528-2:2018 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
emission
airborne sound radiated by the generating set under test
3.2
emission sound pressure
p
e
sound pressure, at a workstation 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
Note 1 to entry: Emission sound pressure is expressed in pascals.
3.3
emission sound pressure level
L
pe
ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure, p , to
e
the square of a reference value, p , expressed in decibels by Formula (1):
p
e
L = 10 lg (1)
pe
p
where the reference value, p , is 20 µPa
3.4
time-averaged emission sound pressure level
L
pe,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
e 1 2
square of a reference value, p , expressed in decibels by Formula (2):
t
 2 
pt()dt
e
 ∫ 
t
T
L = 10 lg  (2)
pe,T
 p 
 
 
where the reference value, p , is 20 µPa
Note 1 to entry: In general, the subscript “T” is omitted, since time-averaged sound pressure levels are necessarily
determined over a certain measurement time interval.
Note 2 to entry: L denotes the A-weighted emission sound pressure level.
peA
ISO 8528-10:2022(E)
3.5
workstation
operator's position
position in the vicinity of the generating set under test which is intended for the operator
Note 1 to entry: This position is defined as the location in the vicinity of the device(s) mounted to the generating
set for work tasks.
Note 2 to entry: Such devices can be a control panel, an emergency stop button or the most likely device on the
equipment that an operator would interact with.
Note 3 to entry: A generating set can have more than one workstation.
3.6
operator
individual whose workstation is in the vicinity of a machine and who is performing a work task
associated with that machine
4 Symbols
cosϕ
power factor
d measurement distance, in metres
*
apparent directivity index, in decibels
D
Ii
i subscript denoting a particular measuring point
K expanded measurement uncertainty of the sound power level, or of the emission sound pressure
level at the workstation, for a batch of generating sets, in decibels
K A-weighted background noise correction, in decibels
1A
K A-weighted environmental correction, in decibels
2A
L sound pressure level, in decibels
p
surface time-averaged sound pressure level, in decibels
L
p
L emission sound pressure level, in decibels
pe
L A-weighted emission sound pressure level, in decibels
peA
L time-averaged emission sound pressure level, in decibels
pe,T
L time-averaged sound pressure level, for the ith microphone position on the measurement sur-
p,i T
face, in decibels
L time-averaged sound pressure level, in decibels
p,T
L sound power level, in decibels
W
L A-weighted sound power level, in decibels
WA
ΔL difference between the time-averaged sound pressure level of the background noise measured
p
and averaged over the microphone positions, and corresponding time-averaged sound pressure
level of the noise source under test when measured in the presence of this background noise,
in decibels
p sound pressure, in pascals
ISO 8528-10:2022(E)
r measurement radius, in metres
S measurement surface, in square metres
T measurement time interval, in seconds
U expanded measurement uncertainty of the sound power level, or of the emission sound pressure
level at the workstation, for a single generating set, in decibels
*
apparent surface sound pressure level non-uniformity index, in decibels
V
I
5 Selection of the most appropriate method
5.1 General
Table 1 provides a detailed overview of the technical characteristics of the measurements methods in
this document. Table 1 describes noise test codes with two levels of accuracy (grades 2 and 3). It can
help in the selection of the appropriate noise test code.
Table 1 — Technical characteristics of this document
Measurement methods
Emission sound pressure
Sound power level meas- Sound power level meas-
level at the workstation
Parameters urement ISO 8528-10 urement ISO 8528-10
measurement ISO 8528-10
grade 2 grade 3
grade 2
Basic standards refer-
ISO 3744:2010 ISO 3746:2010 ISO 11201:2010
enced
Accuracy Grade 2 engineering Grade 3 survey Grade 2 engineering
Test environment Indoor or outdoor Indoor or outdoor Indoor or outdoor
Type of environment Dedicated to tests In situ Dedicated to tests
Hemi-anechoic rooms, Hemi-anechoic rooms,
Characteristics of envi- large rooms Not especially designed for large rooms
ronment or unobstructed outdoor acoustic tests or unobstructed outdoor
area area
Unspecified field with
Essentially free field over a Essentially free field over a
Acoustic field one or multiple reflecting
reflecting plane reflecting plane
plane(s)
Generating set volume Unlimited Unlimited Unlimited
Noise declaration Noise declaration
Applications as per
engineering study for noise Comparative tests engineering study for noise
ISO 12001:1996
reduction reduction
A-weighted sound power A-weighted sound pressure
level level
Frequency bands (octave) A-weighted sound power Frequency bands (octave)
Obtainable quantities
sound power level level sound pressure level
Frequency bands (one-third Frequency bands (one-third
octave) sound power level octave) sound pressure level
ΔL ≥ 6 dB ΔL ≥ 3 dB ΔL ≥ 6 dB
Criterion for back- p p p
ground noise
K ≤ 1,3 dB K ≤ 3 dB K ≤ 1,3 dB
1A 1A 1A
a
For indoor measurements only.
b
Specific studies carried out on generating sets can lead to lower values.
ISO 8528-10:2022(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Measurement methods
Emission sound pressure
Sound power level meas- Sound power level meas-
level at the workstation
Parameters urement ISO 8528-10 urement ISO 8528-10
measurement ISO 8528-10
grade 2 grade 3
grade 2
Criterion for acoustic
a
adequacy of test envi- K ≤ 4 dB K ≤ 7 dB K ≤ 4 dB
2A 2A 2A
ronment
Instrumentation Class 1 Class 2 Class 1
Typical upper bound
values of the standard
1,5 dB 4 dB 1,5 dB
deviation of reproduc-
b
ibility
a
For indoor measurements only.
b
Specific studies carried out on generating sets can lead to lower values.
5.2 Sound power level measurements accuracy grades
5.2.1 General
For sound power level measurements:
— Grade 2 provides more accurate results than grade 3 but involves greater measurement efforts.
— The grade 2 method is based on ISO 3744:2010. The requirements listed in Annex A shall be followed.
— Terms and definitions of ISO 3744:2010 applicable to generating sets are indicated in Table A.1.
— The grade 3 method is based on ISO 3746:2010. The requirements listed in Annex B shall be followed.
— Terms and definitions of ISO 3746:2010 applicable to generating sets are indicated in Table B.1.
— In this document, when the accuracy grade is not specified the requirements apply for grade 2 and
grade 3. The grade 3 method has many requirements in common with the grade 2 method.
5.2.2 Engineering grade (grade 2)
In this accuracy grade, the acoustic environment is analysed to determine its effect upon the
measurements. The environmental correction K shall be less than or equal to 4 dB. The background
2A
noise level is analysed too. Background noise correction K shall be less than or equal to 1,3 dB. The
1A
measuring points are selected according to the characteristics of the generating set. The engineering
method is the preferred method for noise declaration purposes. This method usually provides
information that is sufficient for taking engineering action in many situations, for example, in
connection with noise-abatement programmes.
5.2.3 Survey grade (grade 3)
This accuracy grade needs less time and equipment than grade 2. It may be used for comparison between
generating sets with similar characteristics. The measurements are made in situ with little effort
expended to control the acoustic environment in which the generating set operates. The environmental
correction K shall be less than or equal to 7 dB. The background noise correction K shall be less
2A 1A
than or equal to 3 dB. The survey method is generally of limited value if corrective measures to reduce
the noise are to be evaluated.
NOTE True comparisons can only be made between generating sets when the measurements are classified
in the same accuracy grade.
ISO 8528-10:2022(E)
6 Measuring equipment
6.1 General
ISO 3744:2010, 5.1 and ISO 3746:2010, 5.1 are replaced by subclause A.2.1.
6.2 Calibration
ISO 3744:2010, 5.2 and ISO 3746:2010, 5.2 are replaced by subclause A.2.2.
7 Measuring environment
7.1 General
For accuracy grade 2, ISO 3744:2010, 1.3, and 4.1 apply.
For accuracy grade 3, ISO 3746:2010, 1.3, and 4.1 apply.
7.2 Verification of acoustic adequacy of test environment
For accuracy grade 2, the test environment shall meet the requirements of ISO 3744:2010, 4.3. In
addition, the following considerations shall be taken into account:
— Where it is decided to make measurements in frequency bands, the relevant environmental
correction K shall be determined in each band over the frequency range of interest in accordance
with A.6.
— In many cases, due to the reality of the acoustic properties of the measuring area and the test bench
conditions (this occurs predominantly with larger generating sets), sound power level grade 2 might
not be obtainable using the method described in this document. In special cases with the agreement
of the customer or the accepting company or authority, the accuracy may be improved with the use
of special measuring methods (e.g. sound intensity method in accordance with ISO 9614-1:1993 and
ISO 9614-2:1996, see Annex C).
For accuracy grade 3, the test environment shall meet the requirements of ISO 3746:2010, 8.1 and 4.3.
7.3 Criteria for background noise
For accuracy grade 2, the background noise shall meet the requirements of ISO 3744:2010, 4.2.
For accuracy grade 3, the background noise shall meet the requirements of ISO 3746:2010, 4.2.
In both cases, the following additional considerations shall be taken into account:
— Noise generated by air movement at the microphone itself is classified as background noise.
— For measuring out of doors, a microphone wind cover in accordance with the microphone
manufacturer's specifications shall be used.
— When measurements are done outside, the maximum speed of the wind shall not exceed 6 m/s.
8 Definition of noise source and operating conditions of the generating set
8.1 Definition of noise source under test
The noise of a generating set is defined as the total noise emitted by that generating set. This includes
the surface noise of the engine and the AC or DC alternator, the air intake and discharge noise, exhaust
ISO 8528-10:2022(E)
noise (including the genset muffler, rain cap and tail pipe exhaust outlet), the noise emitted from the
cooling system of the power generator set, the radiator and other fans of the power generator, and the
noise which is emitted, for example, from the joining sections and the base frame, chassis and fuel tank.
In the case of totally or partially encapsulated generating sets, the surface noise is the noise emitted
from the enclosure.
If, as in special cases, one of the above-mentioned noise emissions is not in the measurement results,
then this shall be recorded in the measuring report. Such special cases include:
— in situ: when the exhaust and cooling systems are ducted to a remote site.
— in a test room: when the exhaust of the generating set is ducted out of the test room.
8.2 Location, installation of the generating set
For accuracy grade 2, the generalities in ISO 3744:2010, 6.1 apply.
For accuracy grade 3, the generalities in ISO 3746:2010, 6.1 apply.
For accuracy grade 2, ISO 3744:2010, 6.3, concerning noise source location, shall apply.
For accuracy grade 3, ISO 3746:2010, 6.3, concerning noise source location, shall apply.
In addition, the following considerations shall be taken into account:
— The generating set shall be prepared in accordance with the instructions given by the manufacturer.
— I
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