SIST EN ISO 7779:2019

SLOVENSKI STANDARD
01-marec-2019
1DGRPHãþD
SIST EN ISO 7779:2010
Akustika - Merjenje emisije hrupa informacijskih in telekomunikacijskih naprav
(ISO 7779:2018)
Acoustics - Measurement of airborne noise emitted by information technology and
telecommunications equipment (ISO 7779:2018)
Akustik - Geräuschemissionsmessung an Geräten der Informations- und
Telekommunikationstechnik (ISO 7779:2018)
Acoustique - Mesurage du bruit aérien émis par les équipements liés aux technologies
de l'information et aux télécommunications (ISO 7779:2018)
Ta slovenski standard je istoveten z: EN ISO 7779:2018
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
33.020 Telekomunikacije na splošno Telecommunications in
general
35.020 Informacijska tehnika in Information technology (IT) in
tehnologija na splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 7779
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 17.140.20; 35.020 Supersedes EN ISO 7779:2010
English Version
Acoustics - Measurement of airborne noise emitted by
information technology and telecommunications
equipment (ISO 7779:2018)
Acoustique - Mesurage du bruit aérien émis par les Akustik - Geräuschemissionsmessung an Geräten der
équipements liés aux technologies de l'information et Informations- und Telekommunikationstechnik (ISO
aux télécommunications (ISO 7779:2018) 7779:2018)
This European Standard was approved by CEN on 26 November 2018.

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, 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: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7779:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 7779:2018) 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 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 2019, and conflicting national standards shall be
withdrawn at the latest by June 2019.
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 supersedes EN ISO 7779:2010.
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 7779:2018 has been approved by CEN as EN ISO 7779:2018 without any modification.

INTERNATIONAL ISO
STANDARD 7779
Fourth edition
2018-11
Acoustics — Measurement of airborne
noise emitted by information
technology and telecommunications
equipment
Acoustique — Mesurage du bruit aérien émis par les équipements liés
aux technologies de l'information et aux télécommunications
Reference number
ISO 7779:2018(E)
©
ISO 2018
ISO 7779:2018(E)
© ISO 2018
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 7779:2018(E)
Contents Page
Foreword .vi
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 General definitions . 2
3.2 Acoustical definitions . 4
3.3 Statistical definitions . 7
4 Conformity requirements . 7
5 Installation and operating conditions. 8
5.1 Equipment installation . 8
5.1.1 General. 8
5.1.2 Floor-standing equipment . 8
5.1.3 Table-top equipment . 9
5.1.4 Wall-mounted equipment . 9
5.1.5 Rack-mounted equipment . 9
5.1.6 Hand-held equipment. 9
5.1.7 Sub-assemblies . 9
5.2 Input voltage and frequency .10
5.3 Equipment operation .10
6 Method for determination of sound power levels of equipment in reverberation test
rooms .11
6.1 General .11
6.2 Measurement uncertainty .11
6.3 Test environment .12
6.3.1 General.12
6.3.2 Meteorological conditions .12
6.4 Instrumentation .12
6.4.1 General.12
6.4.2 The microphone and its associated cable .12
6.4.3 Frequency response of the instrumentation system .12
6.4.4 Reference sound source .13
6.4.5 Filter characteristics .13
6.4.6 Calibration .13
6.5 Installation and operation of equipment: general requirements .13
6.6 Microphone positions and source locations .13
6.6.1 General.13
6.6.2 Number of microphone positions, reference sound source locations and
equipment locations .14
6.6.3 Microphone arrangement .14
6.7 Measurement of sound pressure level .14
6.7.1 General.14
6.7.2 Measurement duration .14
6.7.3 Corrections for background noise .14
6.8 Measurement of the sound pressure level of the reference sound source .14
6.9 Calculation of mean time-averaged band sound pressure level .14
6.10 Determination of sound power level .14
6.10.1 Calculation of band sound power levels .14
6.10.2 Calculation of A-weighted sound power level .15
7 Method for determination of sound power levels of equipment under essentially
free‑field conditions over a reflecting plane .17
7.1 General .17
ISO 7779:2018(E)
7.2 Measurement uncertainty .17
7.3 Test environment .18
7.3.1 Essentially free field over a reflecting plane .18
7.3.2 Meteorological conditions .19
7.4 Instrumentation .20
7.4.1 General.20
7.4.2 The microphone and its associated cable .20
7.4.3 Frequency response of the instrumentation system .20
7.4.4 Reference sound source .20
7.4.5 Filter characteristics .20
7.4.6 Calibration .20
7.5 Installation and operation of equipment: General requirements .20
7.6 Measurement surface and microphone positions .21
7.6.1 General.21
7.6.2 Microphone positions on the measurement surface .22
7.7 Measurement of sound pressure levels .22
7.7.1 General.22
7.7.2 Measurement duration .22
7.7.3 Corrections for background noise .22
7.8 Calculation of surface sound pressure level .22
7.9 Determination of sound power levels .23
7.9.1 Calculation of band sound power levels .23
7.9.2 Calculation of A-weighted sound power level .23
8 Method for determination of emission sound pressure levels at defined operator
and bystander positions .23
8.1 General .23
8.2 Measurement uncertainty .24
8.3 Test environment .24
8.3.1 General.24
8.3.2 Meteorological conditions .24
8.4 Instrumentation .25
8.5 Installation and operation of equipment .25
8.6 Microphone positions .25
8.6.1 General.25
8.6.2 At the operator position(s) .25
8.6.3 At the bystander positions .28
8.6.4 Microphone orientation .28
8.7 Measurement of sound pressure levels .28
8.7.1 General.28
8.7.2 Measurement duration .29
8.7.3 Corrections for background noise .29
8.8 Determination of emission sound pressure levels .29
8.8.1 Calculation of band emission sound pressure levels .29
8.8.2 Calculation of A-weighted emission sound pressure levels from band levels .29
8.8.3 Calculation of the mean emission sound pressure level at the bystander
positions .30
9 Measurement uncertainty .30
10 Information to be recorded and reported .32
10.1 Information to be recorded .32
10.1.1 General.32
10.1.2 Equipment under test .32
10.1.3 Acoustical environment .32
10.1.4 Instrumentation .33
10.1.5 Acoustical data .34
10.2 Test report .35
Annex A (normative) Test accessories .37
iv © ISO 2018 – All rights reserved

ISO 7779:2018(E)
Annex B (normative) Measurement surfaces .40
Annex C (normative) Installation and operating conditions for specific equipment categories .46
Annex D (informative) Identification and evaluation of prominent discrete tones .47
Annex E (informative) Background information on the method formerly used for the
detection of impulsive noise.67
Bibliography .68
ISO 7779:2018(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: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This fourth edition cancels and replaces the third edition (ISO 7779:2010), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Clause 3:
— Updates of many items in 3.1 and 3.2 to be consistent with basic standards, such as ISO/TR
25417, ISO 3744, etc.
— Addition of new 3.3 corresponding to new Clause 9.
— Clause 6:
— In 6.4.6, the microphone calibration procedures were amended to be consistent with those of
industrial counterpart, ECMA-74.
— Clause 7:
— In 7.3 (7.3.1), the procedure for test environment qualification was amended to clarify that
any frequency bands, typically low in frequency, not significantly affecting A-weighted sound
power level need not meet the hemi-anechoic room qualification criteria for the purposes of
determining A-weighted sound power level.
vi © ISO 2018 – All rights reserved

ISO 7779:2018(E)
— In 7.4.6, the microphone calibration procedures were amended to be consistent with those of
industrial counterpart, ECMA-74.
— Clause 8:
— In 8.6, new 8.6.1 was inserted to clarify the method of defining operator position and bystander
positions.
— Clause 9:
— Clause 9 was newly inserted.
— In relation to Clause 9, 3.3 was also added, and the descriptions of Tables 1, 5 and 6 (in 6.2, 7.2
and 8.2 respectively) were amended.
— Annex B:
— B.2.2 and B.2.3 were amended to clarify the section of size and microphone positions on the
cylindrical measurement surface, respectively.
— Annex D:
— In D.1, D.8, D.9.5, D.10.3 and D.10.4, descriptions were amended to clarify that Annex D permits
to use FFT data below 89,1 Hz and above 11 200 Hz to calculate tone-to-noise ratio and
prominence ratio.
— In D.9.7 and D.10.7, notes were added to mention that new metrics for detecting prominent
discrete tone, (1) total tone-to-noise ratio and (2) total prominence ratio are under development.
— Annex E:
— The measurement method stated in Annex E became out of date and was removed. But the
annex structure is still maintained for the possible development of a new method (the title of
the annex was amended accordingly).
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.
ISO 7779:2018(E)
Introduction
This document specifies methods for the measurement of airborne noise emitted by information
technology and telecommunications (ITT) equipment. Hitherto, a wide variety of methods have been
applied by individual manufacturers and users to satisfy particular equipment or application needs.
These diverse practices have, in many cases, made comparison of noise emission difficult. This
document simplifies such comparisons and is the basis for the declaration of the noise emission levels
of ITT equipment.
In order to ensure accuracy, validity and acceptability, this document is based on the basic International
Standards for determination of the sound power level and for determination of the emission sound
pressure level at the operator position and bystander positions. Furthermore, implementation is
simplified by conformity with these International Standards.
In many cases, free-field conditions over a reflecting plane are realised by hemi-anechoic rooms.
These rooms can be particularly useful during product design to locate and to improve individual
contributing noise sources. Reverberation test rooms can be more economical for production control
and for obtaining sound power levels for noise emission declaration purposes.
The method for measuring the emission sound pressure level at the operator or bystander positions
(based on ISO 11201) is specified in a separate clause, as this level is not considered to be primary noise
emission declaration information. The measurements can, however, be carried out in conjunction with
those for sound power determination in a free field over a reflecting plane.
For comparison of similar equipment, it is essential that the installation conditions and mode of
operation be the same. In Annex C, these parameters are standardized for many categories of equipment.
This document is based on ECMA-74.
viii © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 7779:2018(E)
Acoustics — Measurement of airborne noise emitted
by information technology and telecommunications
equipment
1 Scope
This document specifies procedures for measuring and reporting the noise emission of information
technology and telecommunications equipment.
NOTE 1 This document is considered part of a noise test code (see 3.1.2) for this type of equipment and is
based on basic noise emission standards (see 3.1.1) ISO 3741, ISO 3744, ISO 3745, ISO 9295 and ISO 11201.
The basic emission quantity is the A-weighted sound power level, which can be used for comparing
equipment of the same type but from different manufacturers, or for comparing different equipment.
Three basic noise emission standards for determination of the sound power levels are specified in this
document in order to avoid undue restriction on existing facilities and experience. ISO 3741 specifies
comparison measurements in a reverberation test room; ISO 3744 and ISO 3745 specify measurements
in an essentially free field over a reflecting plane. Any of these three basic noise emission standards
can be selected and used exclusively in accordance with this document when determining sound power
levels of a machine.
The A-weighted sound power level is supplemented by the A-weighted emission sound pressure level
determined at the operator position or the bystander positions, based on basic noise emission standard
ISO 11201. This sound pressure level is not a level of noise immission at a work station (see 3.2.12), but
it can assist in identifying any potential problems that could cause annoyance, activity interference or
hearing damage to operators and bystanders.
Methods for determination of whether the noise emission includes prominent discrete tones are
specified in Annex D.
This document is suitable for type tests and provides methods for manufacturers and testing
laboratories to obtain comparable results.
The methods specified in this document allow the determination of noise emission levels for a functional
unit (see 3.1.4) tested individually.
The procedures apply to equipment which emits broad-band noise, narrow-band noise and noise which
contains discrete-frequency components, or impulsive noise.
The sound power and emission sound pressure levels obtained can serve noise emission declaration
[3]
and comparison purposes (see ISO 9296 ).
NOTE 2 The sound power levels and emission sound pressure levels obtained are not intended to be considered
[11]
as installation noise immission levels; however, they can be used for installation planning (see ECMA TR/27 ).
If sound power levels obtained are determined for a number of functional units of the same production
[3]
series, they can be used to determine a statistical value for that production series (see ISO 9296 ).
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 7779:2018(E)
ISO 3741, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
sound pressure — Precision methods for reverberation test rooms
ISO 3744, 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 3745, 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 6926, Acoustics — Requirements for the performance and calibration of reference sound sources used
for the determination of sound power levels
ISO 9295, Acoustics — Determination of high-frequency sound power levels emitted by machinery and
equipment
ISO 11201, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound
pressure levels at a work station and at other specified positions in an essentially free field over a reflecting
plane with negligible environmental corrections
ISO 11203, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound
pressure levels at a work station and at other specified positions from the sound power level
IEC 60942, Electroacoustics — Sound calibrators
IEC 61183, Electroacoustics — Random-incidence and diffuse-field calibration of sound level meters
IEC 61260-1, Electroacoustics — Octave-band and fractional-octave-band filters — Part 1: Specifications
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
1)
ECMA-74 , Measurement of airborne noise emitted by information technology and telecommunications
equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3744, ISO 11201 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1 General definitions
3.1.1
basic noise emission standard
B-type standard
standard which specifies a procedure for determining the noise emission of machinery and equipment
in such a way as to obtain reliable, reproducible results with a specified degree of accuracy
[SOURCE: ISO 12001:1996, 3.1]
1) Available [viewed 2017-04-07] at: http: //www .ecma -international .org/publications/files/ECMA -ST/ECMA -74
.pdf
2 © ISO 2018 – All rights reserved

ISO 7779:2018(E)
3.1.2
noise test code
C-type standard
standard that is applicable to a particular class, family or type of machinery or equipment which
specifies all the information necessary to carry out efficiently the determination, declaration and
verification of the noise emission characteristics under standardized conditions
[3]
Note 1 to entry: This document, together with ISO 9296 , comprises the noise test codes for ITT equipment.
[SOURCE: ISO 12001:1996, 3.2, modified — Note 1 to entry was added.]
3.1.3
information technology and telecommunications equipment
ITT equipment
equipment for information processing, and components thereof, used in homes, offices, server
installations, telecommunications installations or similar environments
3.1.4
functional unit
unit of information technology and telecommunications equipment, either with or without its own
end-use enclosure, that is tested or intended to be tested in accordance with the procedures of this
document
Note 1 to entry: A functional unit can comprise more than one unit of ITT equipment when such units are to be
tested together in accordance with the methods of this document. A functional unit can also comprise one or
more units of ITT equipment coupled to one or more units of non-ITT equipment, such as power modules, water
pumps, or refrigeration units, when such equipment is necessary for the normal operation of the ITT equipment.
Note 2 to entry: Functional units of ITT equipment can take on a wide range of forms, including commercially
available products, prototype units under development or sub-assemblies and components thereof.
3.1.5
work station
operator position
position in the vicinity of the equipment under test which is intended for the operator
Note 1 to entry: This term does not refer to a computer “workstation”, which denotes a high-performance, single-
user computer.
3.1.6
operating mode
condition in which the equipment being tested is performing its intended function(s)
3.1.7
idle mode
one or more steady-state conditions in which the equipment being tested is energized but is not
operating
3.1.8
floor‑standing equipment
functional unit which is intended to be installed on the floor
3.1.9
table-top equipment
functional unit which has a complete enclosure and which is intended to be installed or used on a table,
desk or separate stand
3.1.10
wall-mounted equipment
functional unit which is normally mounted against or in a wall and which does not have a stand of its own
ISO 7779:2018(E)
3.1.11
sub-assembly
functional unit, generally without its own end-use enclosure, intended to be installed in another unit of
ITT equipment or assembled together with other sub-assemblies or units of ITT equipment into a single
end-use enclosure
3.1.12
rack-mountable unit
functional unit that is designed to be installed in an end-use enclosure in the form of a rack, frame, or
cabinet, either fully enclosed, partially enclosed, or open frame
3.1.13
rack-enclosed system
functional unit in the form of a rack, frame, or cabinet containing one or more rack-mountable units
Note 1 to entry: Rack-enclosed systems represent a wide variety of ITT equipment, depending on the particular
configuration of the rack-mountable units in the rack or enclosure. These can be server systems, storage systems,
I/O systems, networking systems or “integrated” systems of these or other types of rack-mountable units.
3.1.14
hand-held equipment
functional unit, generally small and lightweight, intended to be supported in one’s hand(s) during
operation
3.1.15
standard test table
rigid table having a top surface of at least 0,5 m and length of the top plane not less than 700 mm
Note 1 to entry: The design for the standard test table is shown in A.1.
3.2 Acoustical definitions
3.2.1
emission
noise emission
airborne sound radiated by a well-defined noise source (e.g. the equipment under test)
Note 1 to entry: Noise emission descriptors can be incorporated into a product declaration 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 an operator position (work station) and/or at bystander positions (if no operator
position is defined) in the vicinity of the source.
3.2.2
sound pressure
p
difference between instantaneous total pressure and static pressure
Note 1 to entry: Sound pressure is expressed in pascals.
Note 2 to entry: The symbol p for instantaneous sound pressure is often used without modification to represent
a root-mean-square (RMS) sound pressure.
Note 3 to entry: See ISO 80000-8.
4 © ISO 2018 – All rights reserved

ISO 7779:2018(E)
3.2.3
sound pressure level
L
p
ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p, to the square
of a reference value, p , expressed in decibels
p
L = 10 lg dB
p
p
where the reference value, p , is 20 µPa
[SOURCE: ISO/TR 25417:2007, 2.2, modified — Notes to entry were removed.]
3.2.4
time-averaged 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 sound
pressure, p, during a stated time interval of duration, T (starting at t and ending at t ), to the square of
1 2
a reference value, p , expressed in decibels
t
 
 2 
pt()dt
 ∫ 
T
 t 
L = 10 lg dB
 
pT,
p
 
 
 
 
where the reference value, p , is 20 μPa
Note 1 to entry: Because of practical limitations of the measuring instruments, p is always understood to denote
the square of a frequency-weighted and frequency-band-limited sound pressure. If a specific frequency weighting
as specified in IEC 61672-1 and/or specific frequency bands are applied, this should be indicated by appropriate
subscripts; e.g. L denotes the A-weighted time-averaged sound pressure level over 10 s.
p,A,10 s
Note 2 to entry: L can be interpreted as the sound pressure level
...