IEC_61779-6-1999.pdf

INTERNATIONALSTANDARDIEC61779-6First edition1999-06Electrical apparatus for the detectionand measurement of flammable gases Part 6:Guide for the selection,installation,use andmaintenance of apparatus for the detectionand measurement of flammable gasesAppareils lectriques de dtection et de mesuredes gaz combustibles Partie 6:Directives pour le choix,linstallation,lutilisationet lentretien des appareils lectriques de dtectionet de mesure de gaz inflammablesReference numberIEC 61779-6:1999(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.NumberingAs from 1 January 1997 all IEC publications are issued with a designation in the60000 series.Consolidated publicationsConsolidated versions of some IEC publications including amendments areavailable.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to thebase publication,the base publication incorporating amendment 1 and the basepublication incorporating amendments 1 and 2.Validity of this publicationThe technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating to the date of the reconfirmation of the publication is availablein the IEC catalogue.Information on the subjects under consideration and work in progress undertakenby the technical committee which has prepared this publication,as well as the listof publications issued,is to be found at the following IEC sources:IEC web site*Catalogue of IEC publicationsPublished yearly with regular updates(On-line catalogue)*IEC BulletinAvailable both at the IEC web site*and as a printed periodicalTerminology,graphical and letter symbolsFor general terminology,readers are referred to IEC 60050:InternationalElectrotechnical Vocabulary(IEV).For graphical symbols,and letter symbols and signs approved by the IEC forgeneral use,readers are referred to publications IEC 60027:Letter symbols to beused in electrical technology,IEC 60417:Graphical symbols for use on equipment.Index,survey and compilation of the single sheets and IEC 60617:Graphical symbolsfor diagrams.*See web site address on title page.LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.INTERNATIONALSTANDARDIEC61779-6First edition1999-06Electrical apparatus for the detectionand measurement of flammable gases Part 6:Guide for the selection,installation,use andmaintenance of apparatus for the detectionand measurement of flammable gasesAppareils lectriques de dtection et de mesuredes gaz combustibles Partie 6:Directives pour le choix,linstallation,lutilisationet lentretien des appareils lectriques de dtectionet de mesure de gaz inflammablesPRICE CODE IEC 1999 Copyright-all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means,electronic ormechanical,including photocopying and microfilm,without permission in writing from the publisher.International Electrotechnical Commission3,rue de Varemb Geneva,SwitzerlandTelefax:+41 22 919 0300e-mail:inmailiec.ch IEC web site http:/www.iec.chXAFor price,see current catalogue Commission Electrotechnique Internationale International Electrotechnical CommissionLICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 61779-6 IEC:1999(E)CONTENTSPageFOREWORD.4INTRODUCTION.5Clause1 General.61.1 Scope.61.2 Normative references.62 Definitions.73 Measuring principles.113.1 Catalytic sensor.113.2 Thermal conductivity sensor.123.3 Electromagnetic radiation absorption sensor usually infrared.133.4 Semi-conductor sensor.143.5 Electrochemical sensors.143.6 Flame ionization detectors(FID).154 Selection of apparatus.154.1 General.164.2 Selection criteria.164.3 Miscellaneous factors affecting selection of apparatus.185 Behaviour of gas releases.195.1 Nature of a release.195.2 Outdoor sites and open structures.215.3 Buildings and enclosures.215.4 Environmental considerations.226 Installation of fixed gas detection apparatus.226.1 Basic considerations for the installation of fixed systems.226.2 Location of sensors.236.3 Installation of sensors.246.4 Timing of installation during construction operations.256.5 Safety in fixed systems.256.6 Environmental conditions.266.7 Sample lines.276.8 Access for calibration and maintenance.276.9 Commissioning.276.10 Operating instructions,plans and records.28LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.61779-6 IEC:1999(E)3 ClausePage7 Use of portable and transportable flammable gas detection apparatus.287.1 General.287.2 Initial and periodic check procedures for portable and transportable instrumentation.297.3 Guidance on the use of portable and transportable apparatus.298 Special precautions for fixed and portable apparatus.309 Maintenance,routine procedures and general administrative control.319.1 General.319.2