EN 60079-28:2007

Explosive atmospheres - Part 28: Protection of equipment and transmission systems using optical radiation

This part of IEC 60079 explains the potential ignition hazard from equipment using optical radiation intended for use in explosive gas atmospheres. It also covers equipment, which itself is located outside but its emitted optical radiation enters such atmospheres. It describes precautions and requirements to be taken when using optical radiation transmitting equipment in explosive gas atmospheres.

Explosionsfähige Atmosphäre - Teil 28: Schutz von Einrichtungen und Übertragungssystemen, die mit optischer Strahlung arbeiten

Atmosphères explosives - Partie 28: Protection du matériel et des systèmes de transmission utilisant le rayonnement optique

La présente partie de la CEI 60079 explique le risque d'inflammation potentiel à partir de matériel utilisant un rayonnement optique et destiné à être utilisé en atmosphères explosives gazeuses. Elle couvre également le matériel, lui-même situé à l'extérieur mais dont les rayonnements optiques pénètrent de telles atmosphères. Elle décrit les précautions à prendre et les exigences lors de l'utilisation de matériels transmettant des rayonnements optiques dans des atmosphères explosives gazeuses.

Eksplozivne atmosfere - 28. del: Zaščita opreme, ki uporablja optično sevanje, in sistemov za prenos optičnega sevanja (IEC 60079-28:2006)

General Information

• Status: Withdrawn
• Publication Date: 22-Mar-2007
• Withdrawal Date: 30-Sep-2009
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: CLC/TC 31 - Electrical apparatus for explosive atmospheres - General requirements
• Drafting Committee: IEC/TC 31 - Electrical apparatus for potentially explosive atmospheres
• Parallel Committee: IEC/TC 31 - Electrical apparatus for potentially explosive atmospheres
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 01-Jul-2018
• Completion Date: 01-Jul-2018
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Directive: 94/9/EC - Directive 94/9/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Ref Project: SIST EN 60079-28:2007 - Explosive atmospheres -- Part 28: Protection of equipment and transmission systems using optical radiation

Relations

• Replaced By: EN 60079-28:2015 - Explosive atmospheres - Part 28: Protection of equipment and transmission systems using optical radiation
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2007
(NVSOR]LYQHDWPRVIHUHGHO=DãþLWDRSUHPHNLXSRUDEOMDRSWLþQRVHYDQMHLQ
VLVWHPRY]DSUHQRVRSWLþQHJDVHYDQMD,(&
Explosive atmospheres - Part 28: Protection of equipment and transmission systems
using optical radiation
Explosionsfähige Atmosphäre - Teil 28: Schutz von Einrichtungen und
Übertragungssystemen, die mit optischer Strahlung arbeiten
Atmospheres explosives - Partie 28: Protection du matériel et des systemes de
transmission utilisant le rayonnement optique
Ta slovenski standard je istoveten z: EN 60079-28:2007
ICS:
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60079-28
NORME EUROPÉENNE
March 2007
EUROPÄISCHE NORM
ICS 29.260.20
English version
Explosive atmospheres -
Part 28: Protection of equipment and transmission systems
using optical radiation
(IEC 60079-28:2006)
Atmosphères explosives -  Explosionsfähige Atmosphäre -
Partie 28: Protection du matériel Teil 28: Schutz von Einrichtungen
et des systèmes de transmission und Übertragungssystemen,
utilisant le rayonnement optique die mit optischer Strahlung arbeiten
(CEI 60079-28:2006) (IEC 60079-28:2006)

This European Standard was approved by CENELEC on 2006-10-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60079-28:2007 E
Foreword
The text of document 31/631/FDIS, future edition 1 of IEC 60079-28, prepared by IEC TC 31, Equipment
for explosive atmospheres, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 60079-28 on 2006-10-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-10-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-10-01
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directive 94/9/EC. See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60079-28:2006 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 60079-1 NOTE Harmonized as EN 60079-1:2004 (not modified).
IEC 60079-2 NOTE Harmonized as EN 60079-2:2004 (not modified).
IEC 60079-7 NOTE Harmonized as EN 60079-7:2007 (not modified).
IEC 60079-14 NOTE Harmonized as EN 60079-14:2003 (not modified).
IEC 60079-15 NOTE Harmonized as EN 60079-15:2005 (not modified).
IEC 60079-26 NOTE Harmonized as EN 60079-26:2004 (not modified).
IEC 61241-0 NOTE Harmonized as EN 61241-0:2006 (modified).
IEC 61241-4 NOTE Harmonized as EN 61241-4:2006 (not modified).
IEC 61241-10 NOTE Harmonized as EN 61241-10:2004 (not modified).
IEC 61241-11 NOTE Harmonized as EN 61241-11:2006 (not modified).
IEC 61241-18 NOTE Harmonized as EN 61241-18:2004 (not modified).
__________
- 3 - EN 60079-28:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
IEC 60079 Series Electrical apparatus for explosive gas EN 60079 Series
atmospheres
1) 2)
IEC 60079-0 (mod) - Electrical apparatus for explosive gas EN 60079-0 2006
atmospheres -
Part 0: General requirements
1) 2)
IEC 60079-10 - Electrical apparatus for explosive gas EN 60079-10 2003
atmospheres -
Part 10: Classification of hazardous areas

1) 2)
IEC 60079-11 - Explosive atmospheres - EN 60079-11 2007
Part 11: Equipment protection by intrinsic
safety "i"
1) 2)
IEC 60825-2 - Safety of laser products - EN 60825-2 2004
Part 2: Safety of optical fibre communication
systems (OFCS)
IEC 61508 Series Functional safety of EN 61508 Series
electrical/electronic/programmable electronic
safety-related systems
IEC 61511 Series Functional safety - Safety instrumented EN 61511 Series
systems for the process industry sector

1)
Undated reference.
2)
Valid edition at date of issue.

Annex ZZ
(informative)
Coverage of Essential Requirements of EC Directives
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers only the
following essential requirements out of those given in Annex II of the EC Directive 94/9/EC:
– ER 1.0.1 to ER 1.0.4, ER 1.0.5 (partly)
– ER 1.2.1, ER 1.2.6, ER 1.2.8 to ER 1.2.9
– ER 1.3.1
– ER 1.5.1
– ER 2.1.1 (partly)
– ER 2.2.1 (partly)
– ER 2.3.1 (partly)
Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive concerned.
WARNING: Other requirements and other EC Directives may be applicable to the products falling within
the scope of this standard.
NORME CEI
INTERNATIONALE
IEC
60079-28
INTERNATIONAL
Première édition
STANDARD
First edition
2006-08
Atmosphères explosives –
Partie 28:
Protection du matériel et des systèmes de
transmission utilisant le rayonnement optique

Explosive atmospheres –
Part 28:
Protection of equipment and transmission
systems using optical radiation

 IEC 2006 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
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60079-28  IEC:2006 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11
1 Scope.13
2 Normative references .15
3 Terms and definitions .15
4 General requirements .21
4.1 Optical equipment .21
4.2 Risk levels.21
5 Types of protection.23
5.1 General .23
5.2 Requirements for inherently safe optical radiation “op is” .23
5.3 Requirements for protected optical radiation “op pr” .27
5.4 Optical radiation interlock with optical fibre breakage “op sh” .29
5.5 Suitability of types of protection.29
6 Type verifications and tests .31
6.1 Test set-up for ignition tests .31
6.2 Reference test.33
6.3 Test mixtures .35
6.4 Tests for pulse trains and pulses between 1 ms and 1 s duration .35
7 Marking .35
7.1 General .35
7.2 Marking information.37
7.3 Examples of marking .37

Annex A (normative) Reference test data.39
Annex B (informative) Ignition mechanisms .41
Annex C (normative) Ignition hazard assessment.53
Annex D (informative)  Typical optical fibre cable design .57
Annex E (informative) Introduction of an alternative risk assessment method
encompassing “equipment protection levels” for Ex equipment .59

Bibliography.69

Figure 1 – Figure B.1 with limit lines for intermediate areas for non-combustible
targets, T1 – T4 atmospheres, apparatus group IIA, IIB or IIC.25
Figure B.1 – Minimum radiant igniting power with inert absorber target (α
=83 %, α =93 %) and continuous wave-radiation of 1 064 nm.47
064 nm 805 nm
Figure B.2 – Minimum radiant igniting power with inert absorber target (α
=83 %, α =93 %) and continuous wave-radiation (PTB: 1 064 nm, HSL:
064 nm 805 nm
805 nm, [24]: 803 nm) for some n-alkanes .49
Figure C.1 – Ignition hazard assessment .53
Figure D.1 – Example multi-fibre optical cable design for heavy duty applications.57
Figure D.2 – Typical single optical fibre cable design.57

60079-28  IEC:2006 – 5 –
Table 1 – Relationship between EPL and the probability of an ignition source.21
Table 2 – Safe optical power and irradiance for hazardous locations categorized by
apparatus group and temperature class .23
Table 3 – Optical interlock availability or ignition risk reduction factor by EPL.29
Table 4 – Application of types of protection for optic systems based on EPLs .31
Table A.1 – Reference values for ignition tests with a mixture of propane in air at
40 °C mixture temperature .39
Table B.1 – AIT (auto ignition temperature), MESG (maximum experimental safe gap)
and measured ignition powers of the chosen combustibles for inert absorbers as the
target material (α =83 %, α =93) .45
1 064 nm 805 nm
i,min
Table B.2 – Comparison of measured minimum igniting optical pulse energy (Q )
e,p
at 90 µm beam diameter with auto ignition temperatures (AIT) and minimum ignition
energies (MIE) from literature [25] at concentrations in percent by volume (ϕ) .51
Table E.1 – Traditional relationship of EPLs to zones (no additional risk assessment) .
...