Explosive atmospheres — Licensed Copy: x x, Mott …

1 BRITISH STANDARDBS EN 60079-29-2: 2007 Explosive atmospheres Part 29-2: Gas detectors Selection, installation, use and maintenance of detectors for flammable gases and oxygenICS ; Licensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSIBS EN 60079-29-2:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 February 2008 BSI 2008 ISBN 978 0 580 54363 0 National forewordThis British Standard is the UK implementation of EN 60079-29-2:2007. It is identical to IEC 60079-29-2:2007. It supersedes BS EN 50073:1999, which will be withdrawn on 1 November UK participation in its preparation was entrusted by Technical Committee GEL/31, Equipment for Explosive atmospheres , to Subcommittee GEL/31/19, Gas list of organizations represented on this committee can be obtained on request to its publication does not purport to include all the necessary provisions of a contract.

2 Users are responsible for its correct with a British Standard cannot confer immunity from legal issued since publicationDateCommentsLicensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD EN 60079-29-2 NORME EUROP ENNE EUROP ISCHE NORM November 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europ en de Normalisation Electrotechnique Europ isches Komitee f r 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 60079-29-2:2007 E ICS Supersedes EN 50073:1999 Incorporates Corrigendum December 2007 English version Explosive atmospheres - Part 29-2: Gas detectors - Selection, installation, use and maintenance of detectors for flammable gases and oxygen (IEC 60079-29-2:2007) Atmosph res explosives - Partie 29-2: D tecteurs de gaz - S lection, installation, utilisation et maintenance des d tecteurs de gaz inflammables et d'oxyg ne (CEI 60079-29-2:2007) Explosionsf hige Atmosph re - Teil 29-2: Gasmessger te - Auswahl, Installation, Einsatz und Wartung von Ger ten f r die Messung von brennbaren Gasen und Sauerstoff (IEC 60079-29-2:2007) This European Standard was approved by CENELEC on 2007-11-01.

3 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.

4 Licensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSIEN 60079-29-2:2007 2 Foreword The text of document 31/696/FDIS, future edition 1 of IEC 60079-29-2, prepared by IEC TC 31, Equipment for Explosive atmospheres , was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60079-29-2 on 2007-11-01. This European Standard supersedes EN 50073:1999. This part of EN 60079-29 is to be used in conjunction with the following standards: EN 60079-0, Electrical apparatus for Explosive gas atmospheres Part 0: General requirements EN 60079-29-1, Explosive atmospheres Part 29-1: Gas detectors Performance requirements of detectors for flammable gases.

5 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) 2008-11-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-11-01 Annex ZA has been added by CENELEC. The contents of the corrigendum of December 2007 have been included in this copy. _____ Endorsement notice The text of the International Standard IEC 60079-29-2:2007 was approved by CENELEC as a European Standard without any modification. _____ Licensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSI 3 EN 60079-29-2:2007 CONTENTS INTRODUCTION ..7 1 Scope ..9 2 Normative references.

6 10 3 Terms and definitions ..10 4 Basic information on the properties, behaviour, and detection of gases and vapours ..16 Detecting gases and vapours Safety when monitoring for flammable gases where personnel could be present ..17 Some common properties of gases and vapours ..18 The differences between detecting gases and Detection of gases ..19 Detection of vapours ..21 Oxygen Chemical reaction of oxygen, with solid Chemical reaction of oxygen, with gaseous products ..24 Dilution of the air by displacement by some other gas or vapour ..25 5 Measuring principles ..26 Catalytic sensors ..27 Common Limitations ..27 Interferences ..28 Poisoning ..28 Thermal conductivity Common Limitations ..29 Interferences.

7 30 Poisoning ..30 Infrared sensors ..30 Common Limitations ..31 Interferences ..31 Poisoning ..31 Semiconductor sensors ..32 Common Limitations ..32 Interferences ..32 Poisoning ..33 Electrochemical sensors ..33 Common Limitations ..33 Interferences ..34 Poisoning ..34 Flame ionization detectors (FID) ..35 Common Limitations ..35 Licensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSIEN 60079-29-2:2007 4 Interferences ..35 Poisoning ..36 Flame temperature analysers (FTA) ..36 Common Limitations ..36 Interferences ..36 Poisoning ..36 Photo Ionisation Detector (PID) ..36 Common Limitations ..37 Interferences ..37 Poisoning ..37 Paramagnetic oxygen Common Limitations.

8 38 Interference ..38 Poisoning ..38 6 Selection of General ..39 Selection criteria ..39 General criteria ..39 Gases to be detected by the Intended application of the Transportable apparatus ..43 Miscellaneous factors affecting selection of apparatus ..44 Electromagnetic immunity ..44 Intended zone(s) of use ..44 7 Behaviour of gas releases ..44 Nature of a Release rate of gas or vapour ..44 Flammable Ventilation ..45 Relative density of the released gas or vapour ..46 Temperature and/or pressure ..46 Other parameters to be Outdoor sites and open Buildings and enclosures ..47 Unventilated buildings and enclosures ..47 Ventilated buildings and enclosures ..47 Natural ventilation.

9 47 Mechanical Environmental considerations ..48 8 Design and installation of fixed gas detection systems ..48 Basic considerations for the installation of fixed systems ..49 Location of detection points ..50 Licensed Copy: x x, Mott Macdonald, 04/11/2009 08:00, Uncontrolled Copy, (c) BSI 5 EN 60079-29-2:2007 General site Environmental conditions ..51 Access for calibration and maintenance ..53 Additional considerations for sample Summary of considerations for the location of sensors or sampling points ..54 Installation of Integrity and safety of fixed systems ..56 Redundancy in fixed systems ..56 Protection against loss of main power Timing of installation during construction operations ..57 Commissioning.

10 57 Initial gas calibration ..57 Adjustment of alarm set points ..58 Operating instructions, plans and records ..58 9 Use of portable and transportable flammable gas detection apparatus ..59 General ..59 Initial and periodic check procedures for portable and transportable Inspection and field-check (response check)..60 Routine checks and recalibration ..61 Maintenance and recalibration ..62 Guidance on the use of portable and transportable apparatus ..63 Electrical safety in hazardous atmospheres ..63 Safety of personnel ..63 Spot tests and sampling ..63 Sampling above liquids ..64 Avoidance of condensation ..64 Poisoning of Changes of Accidental Minimalist operation, the Read and run concept.