EN IEC 60942:2018
(Main)Electroacoustics - Sound calibrators
Electroacoustics - Sound calibrators
This document specifies the performance requirements for three classes of sound calibrator: class LS (Laboratory Standard), class 1 and class 2. Acceptance limits are smallest for class LS and greatest for class 2 instruments. Class LS sound calibrators are normally used only in the laboratory; class 1 and class 2 are considered as sound calibrators for field use. A class 1 sound calibrator is primarily intended for use with a class 1 sound level meter and a class 2 sound calibrator primarily with a class 2 sound level meter, as specified in IEC 61672-1. The acceptance limits for class LS sound calibrators are based on the use of a laboratory standard microphone, as specified in IEC 61094-1, for demonstrations of conformance to the requirements of this document. The acceptance limits for class 1 and class 2 sound calibrators are based on the use of a working standard microphone, as specified in IEC 61094-4, for demonstrations of conformance to the requirements of this document. To promote consistency of testing of sound calibrators and ease of use, this document contains three normative annexes – Annex A "Pattern evaluation tests", Annex B "Periodic tests", Annex C "Pattern evaluation report", and two informative Annexes – Annex D "Relationship between tolerance interval, corresponding acceptance interval and the maximum-permitted uncertainty of measurement" and Annex E "Example assessments of conformance to specifications of this document". This document does not include requirements for equivalent free-field or random-incidence sound pressure levels, such as can be used in the overall sensitivity adjustment of a sound level meter. A sound calibrator can provide other functions, for exammple, tonebursts. Requirements for these other functions are not included in this document.
Elektroakustik - Schallkalibratoren
Électroacoustique - Calibreurs acoustiques
Le présent document spécifie les exigences de performance de trois classes de calibreurs acoustiques: la classe LS (Laboratory Standard, étalon de laboratoire), la classe 1 et la classe 2. Les limites d'acceptation les plus faibles concernent la classe LS et les plus élevées concernent les appareils de classe 2. Les calibreurs acoustiques de classe LS ne sont normalement utilisés qu'en laboratoire; les appareils de classe 1 et de classe 2 sont considérés comme des calibreurs acoustiques utilisés sur le terrain. Un calibreur de classe 1 est prévu pour être utilisé principalement avec un sonomètre de classe 1 et un calibreur de classe 2 est prévu pour être utilisé principalement avec un sonomètre de classe 2, tel qu'il est spécifié dans l'IEC 61672-1. Les limites d'acceptation concernant les calibreurs de classe LS pour démontrer la conformité avec les exigences du présent document sont basées sur l'utilisation d'un microphone étalon de laboratoire spécifié dans l'IEC 61094-1. Les limites d'acceptation concernant les calibreurs acoustiques de classe 1 et 2 pour démontrer la conformité avec les exigences du présent document sont basées sur l'utilisation d'un microphone étalon de travail spécifié dans l'IEC 61094-4. Par souci d'homogénéité des essais des calibreurs acoustiques et de facilité d'utilisation, le présent document contient trois annexes normatives: l'Annexe A "Essais d'évaluation de modèle", l'Annexe B "Essais périodiques" et l'Annexe C "Rapport d'évaluation de modèle", et deux annexes informatives: l'Annexe D "Relation entre l'intervalle de tolérance, l'intervalle d'acceptation correspondant et l'incertitude de mesure maximale admise" et l'Annexe E "Exemples d'évaluation de conformité avec les spécifications du présent document". Le présent document n'inclut pas les exigences concernant les niveaux de pression acoustique équivalents en champ libre ou en incidence aléatoire, tels qu'ils peuvent être utilisés pour le réglage de la sensibilité globale d'un sonomètre. Un calibreur acoustique peut comporter d'autres fonctions, comme la production de bruits impulsionnels. Le présent document ne comporte pas d'exigences pour ces autres fonctions.
Elektroakustika - Kalibratorji za zvokomere (IEC 60942:2017)
Ta dokument določa zahteve glede delovanja za tri razrede kalibratorja zvoka: razred LS (laboratorijski standard), razred 1 in razred 2. Meje sprejemljivosti so najnižje za instrumente razreda LS in najvišje za instrumente razreda 2. Kalibratorji zvoka razreda LS se običajno uporabljajo le v laboratoriju; kalibratorji razreda 1 in 2 se smatrajo za kalibratorje zvoka za uporabo na terenu. Kalibrator zvoka razreda 1 je primarno namenjen za uporabo z merilnikom zvočne jakosti razreda 1, kalibratorj zvoka razreda 2 pa primarno za merilnik zvočne jakosti razreda 2, kot je opredeljeno v standardu IEC 61672-1.
Meje sprejemljivosti za kalibratorje zvoka razreda LS temeljijo na uporabi laboratorijskih standardnih mikrofonov, kot je opredeljeno v standardu IEC 61094-1, za dokazovanje skladnosti z zahtevami tega dokumenta. Meje sprejemljivosti za kalibratorje zvoka razreda 1 in 2 temeljijo na uporabi delujočih standardnih mikrofonov, kot je opredeljeno v standardu IEC 61094-4, za dokazovanje skladnosti z zahtevami tega dokumenta.
Za spodbujanje doslednosti preskušanja kalibratorjev zvoka in enostavne uporabe ta dokument vsebuje tri normativne dodatke – dodatek A »Preskusi ocenjevanja vzorcev«, dodatek B »Redni preskusi«, dodatek C »Poročilo o ocenjevanju vzorcev« in dva informativna dodatka – dodatek D »Razmerje med intervalom tolerance, ustreznim intervalom sprejemljivosti in največjo dovoljeno negotovost pri merjenju« in dodatek E »Primeri ocen skladnosti s specifikacijami tega dokumenta«.
Ta dokument ne vključuje zahtev za ravni zvočnega tlaka v odprtem prostoru ali ravni naključne pojavnosti, ki se lahko uporabljajo pri splošni nastavitvi občutljivosti merilnika zvočne jakosti.
Kalibrator zvoka lahko zagotovi druge funkcije, na primer, »toneburst«. Zahteve za te druge funkcije niso vključene v ta dokument.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2018
1DGRPHãþD
SIST EN 60942:2004
Elektroakustika - Kalibratorji za zvokomere (IEC 60942:2017)
Electroacoustics - Sound calibrators (IEC 60942:2017)
Ta slovenski standard je istoveten z: EN IEC 60942:2018
ICS:
17.140.50 Elektroakustika Electroacoustics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60942
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2018
ICS 17.140.50; 33.100.20 Supersedes EN 60942:2003
English Version
Electroacoustics - Sound calibrators
(IEC 60942:2017)
Électroacoustique - Calibreurs acoustiques Elektroakustik - Schallkalibratoren
(IEC 60942:2017) (IEC 60942:2017)
This European Standard was approved by CENELEC on 2018-01-03. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60942:2018 E
European foreword
The text of document 29/962/FDIS, future edition 4 of IEC 60942, prepared by IEC/TC 29
"Electroacoustics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be (dop) 2018-10-03
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2021-01-03
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60942:2003.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 60942:2017 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60942:2003 NOTE Harmonized as EN 60942:2003 (not modified).
IEC 61094-2:2009 NOTE Harmonized as EN 61094-2:2009 (not modified).
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-801 1994 International Electrotechnical Vocabulary - -
(IEV) -- Chapter 801: Acoustics and
electroacoustics
IEC 61000-4-2 2008 Electromagnetic compatibility (EMC) -- Part EN 61000-4-2 2009
4-2: Testing and measurement techniques
- Electrostatic discharge immunity test
IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) -- Part EN 61000-4-3 2006
4-3: Testing and measurement techniques
- Radiated, radio-frequency,
electromagnetic field immunity test
IEC 61000-4-20 2010 Electromagnetic compatibility (EMC) -- Part EN 61000-4-20 2010
4-20: Testing and measurement
techniques - Emission and immunity
testing in transverse electromagnetic
(TEM) waveguides
IEC 61000-6-1 2005 Electromagnetic compatibility (EMC) -- Part EN 61000-6-1 2007
6-1: Generic standards - Immunity for
residential, commercial and light-industrial
environments
IEC 61000-6-2 2005 Electromagnetic compatibility (EMC) -- Part EN 61000-6-2 2005
6-2: Generic standards - Immunity for
industrial environments
- - + corrigendum Sep. 2005
IEC 61000-6-3 2006 Electromagnetic compatibility (EMC) -- Part EN 61000-6-3 2007
6-3: Generic standards - Emission
standard for residential, commercial and
light-industrial environments
+ A1 2010 + A1 2011
- - + AC 2012
IEC 61094-1 2000 Measurement microphones -- Part 1: EN 61094-1 2000
Specifications for laboratory standard
microphones
IEC 61094-4 1995 Measurement microphones -- Part 4: EN 61094-4 1995
Specifications for working standard
microphones
IEC 61094-5 - Measurement microphones - Part 5: EN 61094-5 -
Methods for pressure calibration of working
standard microphones by comparison
IEC 61672-1 - Electroacoustics - Sound level meters -- EN 61672-1 -
Part 1: Specifications
CISPR 16-1-1 - Specification for radio disturbance and EN 55016-1-1 -
immunity measuring apparatus and
methods -- Part 1-1: Radio disturbance and
immunity measuring apparatus -
Measuring apparatus
CISPR 16-2-3 2016 Specification for radio disturbance and EN 55016-2-3 2017
immunity measuring apparatus and
methods - Part 2-3: Methods of
measurement of disturbances and
immunity - Radiated disturbance
measurements
CISPR 22 2008 Information technology equipment - Radio EN 55022 2010
disturbance characteristics - Limits and
methods of measurement
ISO/IEC Guide 98-3 2008 Uncertainty of measurement - Part 3: - -
Guide to the expression of uncertainty in
measurement (GUM:1995)
ISO 266 1997 Acoustics - Preferred frequencies EN ISO 266 1997
ISO/IEC Guide 99 - International vocabulary of metrology - - -
Basic and general concepts and
associated terms (VIM)
IEC 60942 ®
Edition 4.0 2017-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electroacoustics – Sound calibrators
Électroacoustique – Calibreurs acoustiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.50; 33.100.20 ISBN 978-2-8322-5049-5
– 2 – IEC 60942:2017 © IEC 2017
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 10
4 Reference environmental conditions . 12
5 Requirements . 12
5.1 General . 12
5.2 Adaptors . 14
5.3 Sound pressure level . 15
5.3.1 General . 15
5.3.2 Generated sound pressure level . 15
5.3.3 Short-term level fluctuation . 15
5.3.4 Sound pressure level over range of supply voltage . 16
5.4 Frequency . 16
5.4.1 General . 16
5.4.2 Frequency of sound generated by the sound calibrator . 16
5.5 Influence of static pressure, air temperature and humidity . 17
5.6 Total distortion + noise . 18
5.7 Power supply requirements . 19
5.8 Specification and calibration of microphones . 19
5.8.1 Microphone models and adaptors . 19
5.8.2 Microphone sensitivity level . 19
5.9 Electromagnetic compatibility . 20
5.9.1 General . 20
5.9.2 Radio-frequency emissions . 20
5.9.3 Electrostatic discharges . 20
5.9.4 Immunity to power- and radio-frequency fields . 20
6 Instrument marking and documentation . 21
6.1 Marking of the sound calibrator . 21
6.2 Individual calibration chart for a class LS sound calibrator . 22
6.3 Instruction manual . 22
Annex A (normative) Pattern evaluation tests . 24
A.1 General . 24
A.2 Submission for test . 24
A.3 Principal values . 25
A.4 Marking of the sound calibrator and supplied documentation . 25
A.5 Performance tests at and around reference environmental conditions . 25
A.5.1 General . 25
A.5.2 Orientation . 25
A.5.3 Ambient noise . 25
A.5.4 Microphone specification . 26
A.5.5 Sound pressure level . 26
A.5.6 Sound pressure level stability – Short-term level fluctuation . 27
A.5.7 Frequency . 28
IEC 60942:2017 © IEC 2017 – 3 –
A.5.8 Total distortion + noise . 29
A.6 Environmental tests . 30
A.6.1 General . 30
A.6.2 Influence of static pressure . 30
A.6.3 Acclimatization requirements for tests of the influence of variations in
air temperature and relative humidity . 32
A.6.4 Abbreviated test of influence of air temperature and humidity combined . 32
A.6.5 Influence of air temperature . 35
A.6.6 Influence of relative humidity . 36
A.6.7 Influence of air temperature and humidity combined . 37
A.7 Electromagnetic compatibility . 38
A.7.1 General . 38
A.7.2 Radio-frequency emissions . 38
A.7.3 Electrostatic discharges . 39
A.7.4 Immunity to power- and radio-frequency fields . 40
Annex B (normative) Periodic tests . 42
B.1 General . 42
B.2 Submission for test . 43
B.3 Preliminary inspection . 43
B.4 Performance tests . 43
B.4.1 Orientation . 43
B.4.2 Ambient noise . 43
B.4.3 Environmental conditions . 43
B.4.4 Additional equipment . 43
B.4.5 Microphone specification . 44
B.4.6 Sound pressure level . 44
B.4.7 Frequency . 45
B.4.8 Total distortion + noise . 45
B.5 Calibration of the sound calibrator with other models of microphone . 46
B.6 Documentation . 46
Annex C (normative) Pattern evaluation report . 48
C.1 General . 48
C.2 Marking . 48
C.3 Submission for test . 48
C.4 Pattern evaluation report content . 48
Annex D (informative) Relationship between tolerance interval, corresponding
acceptance interval and the maximum-permitted uncertainty of measurement . 50
Annex E (informative) Example assessments of conformance to specifications of this
document . 51
E.1 General . 51
E.2 Conformance criteria . 51
E.3 Example test results . 51
Bibliography . 54
Figure D.1 – Relationship between tolerance interval, corresponding acceptance
interval and the maximum-permitted uncertainty of measurement . 50
Figure E.1 – Examples of assessment of conformance . 53
– 4 – IEC 60942:2017 © IEC 2017
Table 1 – Sound calibrator classes and designations . 13
Table 2 – Acceptance limits for sound pressure level and short-term level fluctuation,
at and around reference environmental conditions . 16
Table 3 – Acceptance limits for the effect of supply voltage on sound pressure level,
under reference environmental conditions . 16
Table 4 – Acceptance limits for frequency, at and around reference environmental
conditions . 17
Table 5 – Acceptance limits for sound pressure level, over the specified range of
environmental conditions . 18
Table 6 – Acceptance limits for frequency, over the specified range of environmental
conditions . 18
Table 7 – Maximum total distortion + noise . 19
Table A.1 – Maximum-permitted uncertainty of measurement for a coverage probability
of 95 %, for sound pressure level and short-term level fluctuation at and around
reference environmental conditions . 28
Table A.2 – Maximum-permitted uncertainty of measurement for a coverage probability
of 95 % for frequency, at and around reference environmental conditions . 29
Table A.3 – Maximum-permitted uncertainty of measurement for a coverage probability
of 95 % for total distortion + noise, over the appropriate range of environmental
conditions . 30
Table A.4 – Maximum-permitted uncertainty of measurement for a coverage probability
of 95 %, for sound pressure level, over the specified range of environmental conditions . 32
Table A.5 – Maximum-permitted uncertainty of measurement for a coverage probability
of 95 % for frequency, over the specified range of environmental conditions . 35
Table E.1 – Examples of assessment of conformance . 52
IEC 60942:2017 © IEC 2017 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROACOUSTICS – SOUND CALIBRATORS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60942 has been prepared by IEC technical committee 29:
Electroacoustics, in cooperation with the International Organization of Legal Metrology
(OIML).
This fourth edition cancels and replaces the third edition published in 2003, of which it
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) deletion of the class designations, class LS/C, class 1/C and class 2/C;
b) addition of two further class designations, class LS/M and class 1/M, specifically for
pistonphones;
c) addition of an amended criterion for assessing conformance to a specification:
conformance is now demonstrated when (a) measured deviations from design goals do not
exceed the applicable acceptance limits and (b) the uncertainty of measurement does not
exceed the corresponding maximum-permitted uncertainty;
– 6 – IEC 60942:2017 © IEC 2017
d) modification to the short-term level fluctuation test of the sound pressure level stability;
e) change to some environmental test conditions to avoid icing;
f) addition of an alternative test for immunity to radio-frequency fields using transverse
electromagnetic (TEM) waveguides.
The text of this International Standard is based on the following documents:
FDIS Report on voting
29/962/FDIS 29/969/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IEC 60942:2017 © IEC 2017 – 7 –
INTRODUCTION
Sound calibrators are designed to produce one or more known sound pressure levels at one
or more specified frequencies when coupled to specified models of microphone in specified
configurations, for example, with or without protective grid. The sound pressure level
generated by some sound calibrators depends on the static pressure.
Sound calibrators have two principal applications:
a) the determination of the electroacoustical pressure sensitivity of specified models of
microphone in specified configurations;
b) checking or adjusting the overall sensitivity of acoustical measuring devices or systems.
– 8 – IEC 60942:2017 © IEC 2017
ELECTROACOUSTICS – SOUND CALIBRATORS
1 Scope
This document specifies the performance requirements for three classes of sound calibrator:
class LS (Laboratory Standard), class 1 and class 2. Acceptance limits are smallest for
class LS and greatest for class 2 instruments. Class LS sound calibrators are normally used
only in the laboratory; class 1 and class 2 are considered as sound calibrators for field use.
A class 1 sound calibrator is primarily intended for use with a class 1 sound level meter and a
class 2 sound calibrator primarily with a class 2 sound level meter, as specified in
IEC 61672-1.
The acceptance limits for class LS sound calibrators are based on the use of a laboratory
standard microphone, as specified in IEC 61094-1, for demonstrations of conformance to the
requirements of this document. The acceptance limits for class 1 and class 2 sound
calibrators are based on the use of a working standard microphone, as specified in
IEC 61094-4, for demonstrations of conformance to the requirements of this document.
To promote consistency of testing of sound calibrators and ease of use, this document
contains three normative annexes – Annex A "Pattern evaluation tests", Annex B "Periodic
tests", Annex C "Pattern evaluation report", and two informative Annexes – Annex D
"Relationship between tolerance interval, corresponding acceptance interval and the
maximum-permitted uncertainty of measurement" and Annex E "Example assessments of
conformance to specifications of this document".
This document does not include requirements for equivalent free-field or random-incidence
sound pressure levels, such as can be used in the overall sensitivity adjustment of a sound
level meter.
A sound calibrator can provide other functions, for example, tonebursts. Requirements for
these other functions are not included in this document.
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.
IEC 60050-801:1994, International Electrotechnical Vocabulary – Chapter 801: Acoustics and
electroacoustics
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measure-
ment techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-20:2010, Electromagnetic compatibility (EMC) – Part 4-20: Testing and
measurement techniques – Emission and immunity testing in transverse electromagnetic
(TEM) waveguides
IEC 60942:2017 © IEC 2017 – 9 –
IEC 61000-6-1:2005, Electromagnetic compatibility (EMC) – Part 6-1: Generic standards –
Immunity for residential, commercial and light-industrial environments
IEC 61000-6-2:2005, Electromagnetic compatibility (EMC) – Part 6-2: Generic standards –
Immunity for industrial environments
IEC 61000-6-3:2006, Electromagnetic compatibility (EMC) – Part 6-3: Generic standards –
Emission standard for residential, commercial and light-industrial environment
IEC 61000-6-3:2006/AMD1:2010
IEC 61094-1:2000, Measurement microphones – Part 1: Specifications for laboratory standard
microphones
IEC 61094-4:1995, Measurement microphones – Part 4: Specifications for working standard
microphones
IEC 61094-5, Electroacoustics – Measurement microphones – Part 5: Methods for pressure
calibration of working standard microphones by comparison
IEC 61672-1, Electroacoustics – Sound level meters – Part 1: Specifications
CISPR 16-1-1, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 1-1: Radio disturbance and immunity measuring apparatus – Measuring
apparatus
CISPR 16-2-3:2016, Specification for radio disturbance and immunity measuring apparatus
and methods – Part 2-3: Methods of measurement of disturbances and immunity – Radiated
disturbance measurements
CISPR 22:2008, Information technology equipment – Radio disturbance characteristics –
Limits and methods of measurement
ISO/IEC Guide 98-3:2008, Uncertainty of measurement – Part 3: Guide to the expression of
uncertainty in measurement (GUM:1995)
ISO 266:1997, Acoustics – Preferred frequencies
ISO/IEC Guide 99, International vocabulary of metrology – Basic and general concepts and
associated terms (VIM)
___________
nd nd rd
2 edition (2005). This 2 edition has been replaced in 2016 by a 3 edition IEC 61000-6-1:2016,
Electromagnetic compatibility (EMC) – Part 6-1: Generic standards – Immunity standard for residential,
rd
commercial and light-industrial environments, but to ensure consistency with other TC 29 standards this 3
edition has not been used or referenced in this document, but will be considered prior to the next revision of
this document.
nd nd rd
2 edition (2005). This 2 edition has been replaced in 2016 by a 3 edition IEC 61000-6-2:2016,
Electromagnetic compatibility (EMC) – Part 6-2: Generic standards – Immunity for industrial environments, but
rd
to ensure consistency with other TC 29 standards this 3 edition has not been used or referenced in this
document, but will be considered prior to the next revision of this document.
th th
6 edition (2008). This 6 edition has been replaced in 2015 by CISPR 32:2015, Electromagnetic compatibility
of multimedia equipment – Emission requirements, but to ensure consistency with other TC 29 standards
CISPR 32:2015 has not been used or referenced in this document, but will be considered prior to the next
revision of this document.
– 10 – IEC 60942:2017 © IEC 2017
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-801 and the
ISO/IEC Guide 99, and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE Definitions for other relevant quantities are given in the documents referenced in Clause 2.
3.1
sound calibrator
device that generates a sinusoidal sound pressure of specified sound pressure level and
frequency when coupled to specified models of microphone in specified configurations
3.2
pistonphone
sound calibrator in which the sound pressure is generated in a fixed air volume by the motion
of one or more pistons, creating a well-defined volume velocity
3.3
specified sound pressure level
sound pressure level(s) generated under reference environmental conditions for use with a
particular microphone model and configuration, valid for either an individual sound calibrator
(in the case of a class LS calibrator) or all sound calibrators of the same model (in the case of
a class 1 or class 2 calibrator)
Note 1 to entry: Specified sound pressure level is expressed in decibels (dB).
Note 2 to entry: The reference value is 20 µPa.
3.4
nominal sound pressure level
close approximation to the specified sound pressure level(s), valid for all sound calibrators of
the same model, rounded to the nearest decibel (intended for marking)
Note 1 to entry: Nominal sound pressure level is expressed in decibels (dB).
Note 2 to entry: The reference value is 20 µPa.
3.5
specified frequency
frequency(ies) of the sound generated by the sound calibrator under reference environmental
conditions, valid for either an individual sound calibrator (in the case of a class LS calibrator)
or all sound calibrators of the same model (in the case of a class 1 or class 2 calibrator)
Note 1 to entry: Specified frequency is expressed in hertz (Hz).
3.6
nominal frequency
close approximation to the specified frequency, often rounded according to ISO 266 (intended
for marking)
Note 1 to entry: Nominal frequency is expressed in hertz (Hz).
IEC 60942:2017 © IEC 2017 – 11 –
3.7
principal sound pressure level
nominal sound pressure level specified in the instruction manual as principal
Note 1 to entry: Where the sound calibrator produces more than one sound pressure level, the manufacturer
identifies one nominal sound pressure level as principal.
Note 2 to entry: Principal sound pressure level is used during demonstration of conformance of the sound
calibrator to the requirements of this document.
Note 3 to entry: Principal sound pressure level is expressed in decibels (dB).
Note 4 to entry: The reference value is 20 µPa.
3.8
principal frequency
nominal frequency specified in the instruction manual as principal
Note 1 to entry: Where the sound calibrator produces more than one frequency, the manufacturer identifies one
nominal frequency as principal.
Note 2 to entry: Principal frequency is used during demonstration of conformance of the sound calibrator to the
requirements of this document.
Note 3 to entry: Principal frequency is expressed in hertz (Hz).
3.9
replication
repeat of a measurement involving coupling the microphone to the sound calibrator and then
completely removing the microphone from the sound calibrator
3.10
total distortion + noise
ratio of the root-mean-square of the total distortion and noise components, including any
harmonics and sub-harmonics, to the root-mean-square of the entire signal
Note 1 to entry: Distortion is the correlated component of the signal due to non-linearity, and noise is the
uncorrelated component.
Note 2 to entry: Total distortion + noise is expressed in per cent (%).
3.11
reference orientation
orientation of a sound calibrator such that the principal axis of the opening of the cavity (the
axis along which the microphone is inserted into the cavity) coincides with the principal
direction of an emitter or receiver of radio-frequency fields, the opening of the cavity facing
away from the emitter or receiver
3.12
reference plane
plane of contact between the microphone and the sound calibrator
3.13
effective load volume of a microphone
volume of air at reference environmental conditions that has the same acoustic compliance as
the cavity bounded by the reference plane, the microphone diaphragm and the outer
cylindrical surface of the microphone at the reference plane, including the equivalent volume
of the microphone (described in IEC 61094-1)
Note 1 to entry: Effective load volume is generally expressed in cubic millimetres (mm ) and may change with
frequency.
– 12 – IEC 60942:2017 © IEC 2017
3.14
coverage probability
probability that the set of true quantity values of a measurand is contained within a specified
coverage interval
[SOURCE: ISO/IEC Guide 98-4:2012, 3.2.8]
3.15
acceptance limit
specified upper or lower bound of permissible measured quantity values
Note 1 to entry: Acceptance limits in this document are analogous to the allowances for design and manufacturing
in IEC 60942:2003.
[SOURCE: ISO/IEC Guide 98-4:2012, 3.3.8, modified – Note 1 to entry has been added.]
4 Reference environmental conditions
Reference environmental conditions for specifying the performance of a sound calibrator are:
– air temperature: 23 °C;
– static pressure: 101,325 kPa;
– relative humidity: 50 %.
5 Requirements
5.1 General
5.1.1 A sound calibrator conforming to the requirements of this document shall have the
characteristics described in Clause 5. Adaptors may be provided to accommodate more than
one model of microphone. For the purpose of this document, any such adaptor is an integral
part of the sound calibrator.
5.1.2 The sound calibrator shall conform to the requirements of this document for one or
more of the sound pressure level and frequency combinations available. A multi-level and
multi-frequency sound calibrator shall conform to the requirements for the same class
designation for all sound pressure level and frequency combinations for which the instruction
manual states that the instrument conforms to the requirements of this document.
Conformance to the requirements of this document shall not be stated for sound pressure
level and frequency settings for which this document provides no acceptance limits.
5.1.3 Throughout this document, where reference is made to a specific class of sound
calibrator, this includes all the designations under that class, unless otherwise stated.
5.1.4 Class LS sound calibrators shall be supplied with an individual calibration chart
containing the information required by 6.2. For class 1 and class 2 sound calibrators, the
specified sound pressure level(s) and specified frequency(ies) shall be given in the instruction
manual. Each specified level shall be defined in terms of an absolute level.
5.1.5 Class LS and class 1 pistonphones that require corrections for the influence of static
pressure to conform to the specifications for the appropriate class shall have the letter "M"
added to their class designation. The permissible classes and designations are described in
Table 1. Sound calibrators designated class LS/M and class 1/M shall not require corrections
for any of the other environmental conditions to achieve the requirements specified for the
appropriate class. For class LS/M and class 1/M sound calibrators, the corrections for static
pressure, necessary for the sound calibrator to conform to the requirements of this document,
IEC 60942:2017 © IEC 2017 – 13 –
shall be stated in the instruction manual, together with the uncertainties of measurement
corresponding to a coverage probability of 95 %.
5.1.6 Sound calibrators designated class LS/M may also claim conformance to the
requirements for a sound calibrator designated class 1/M if they meet the full specifications
described in this document for both classes of sound calibrator.
5.1.7 Sound calibrators, other than those designated class LS/M or class 1/M, shall not
require corrections for any of the environmental conditions to conform to the requirements for
the relevant class.
5.1.8 Sound calibrators designated class LS/M and class1/M shall either be supplied with a
barometer, or the manufacturer shall state the specifications in the instruction manual for any
barometer to be used. A statement shall be included in the instruction manual giving the
uncertainty of the measurement of static pressure required, for a coverage probability of 95%,
so that the ability of a class LS/M or class 1/M sound calibrator to conform to the
requirements for the relevant class is not affected.
NOTE 1 A class LS/M sound calibrator is normally used only in the laboratory where a suitable device is likely to
be available for measuring static pressure.
NOTE 2 Some barometers provide the data directly in the form to be used to correct measured sound pressure
levels to the reference static pressure.
Table 1 – Sound calibrator classes and designations
Class Designation Description
Sound calibrator designed to meet the
specifications of this document for a class LS
LS
device with no corrections for the influence of
environmental conditions
LS
Pistonphone designed to meet the specifications of
this document for a class LS device with the
LS/M
application of corrections for the influence of static
pressure only
Sound calibrator designed to meet the
specifications of this document for a class 1 device
with no corrections for the influence of
environmental conditions
Pistonphone designed to meet the specifications of
this document for a class 1 device with the
1/M
application of corrections for the influence of static
pressure only
Sound calibrator designed to meet the
specifications of this document for a class 2 device
2 2
with no corrections for the influence of
environmental conditions
5.1.9 If a specific orientation of the sound calibrator is to be used to conform to the
requirements of this document, this orientation shall either be indicated on the sound
calibrator, or the indication on the sound calibrator shall refer to the instruction manual, which
shall state the required orientation.
5.1.10 All performance requirements relate to the operation of the sound calibra
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