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

Status
Published
Publication Date
08-Mar-2018
Technical Committee
Drafting Committee
Current Stage
6060 - Document made available
Due Date
09-Mar-2018
Completion Date
09-Mar-2018

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SLOVENSKI STANDARD
SIST EN IEC 60942:2018
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
SIST EN IEC 60942:2018 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60942:2018
---------------------- Page: 2 ----------------------
SIST EN IEC 60942:2018
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
---------------------- Page: 3 ----------------------
SIST EN IEC 60942:2018
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

EN IEC 60942:2018.
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).
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SIST EN IEC 60942:2018
EN IEC 60942:2018 (E)
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
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SIST EN IEC 60942:2018
EN IEC 60942:2018 (E)
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)
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SIST EN IEC 60942:2018
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

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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SIST EN IEC 60942:2018
– 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

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SIST EN IEC 60942:2018
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

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SIST EN IEC 60942:2018
– 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

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SIST EN IEC 60942:2018
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;
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SIST EN IEC 60942:2018
– 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.
---------------------- Page: 12 ----------------------
SIST EN IEC 60942:2018
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.

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SIST EN IEC 60942:2018
– 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 funct
...

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