1、NORME?CEIINTERNATIONALE?IECINTERNATIONAL?721-3-4STANDARD?Deuxime ditionSecond edition1995-01Classification des conditions denvironnement Partie 3:Classification des groupements des agentsdenvironnement et de leurs svrits Section 4:Utilisation poste fixe,non protg contre les intempriesClassification
2、of environmental conditions Part 3:Classification of groups of environmentalparameters and their severities Section 4:Stationary use at non-weatherprotectedlocationsIECNumro de rfrenceReference numberCEI/IEC 721-3-4:1995LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONL
3、Y,SUPPLIED BY BOOK SUPPLY BUREAU.Validit de la prsente publicationLe contenu technique des publications de la CEI est cons-tamment revu par la CEI afin quil reflte ltat actuel dela technique.Des renseignements relatifs la date de reconfirmation dela publication sont disponibles auprs du Bureau Centr
4、al dela CEI.Les renseignements relatifs ces rvisions,ltablis-sement des ditions rvises et aux amendements peuventtre obtenus auprs des Comits nationaux de la CEI etdans les documents ci-dessous:Bulletin de la CEIAnnuaire de la CEIPubli annuellementCatalogue des publications de la CEIPubli annuelleme
5、nt et mis jour rgulirementTerminologieEn ce qui concerne la terminologie gnrale,le lecteur sereportera la CEI 50:Vocabulaire Electrotechnique Inter-national(VEI),qui se prsente sous forme de chapitresspars traitant chacun dun sujet dfini.Des dtailscomplets sur le VEI peuvent tre obtenus sur demande.
6、Voir galement le dictionnaire multilingue de la CEI.Les termes et dfinitions figurant dans la prsente publi-cation ont t soit tirs du VEI,soit spcifiquementapprouvs aux fins de cette publication.Symboles graphiques et littrauxPour les symboles graphiques,les symboles littraux et lessignes dusage gnr
7、al approuvs par la CEI,le lecteurconsultera:la CEI 27:Symboles littraux utiliser enlectro-technique;la CEI 417:Symboles graphiques utilisablessur le matriel.Index,relev et compilation desfeuilles individuelles;la CEI 617:Symboles graphiques pour schmas;et pour les appareils lectromdicaux,la CEI 878:
8、Symboles graphiques pourquipements lectriques en pratique mdicale.Les symboles et signes contenus dans la prsente publi-cation ont t soit tirs de la CEI 27,de la CEI 417,de laCEI 617 et/ou de la CEI 878,soit spcifiquement approuvsaux fins de cette publication.Publications de la CEI tablies par lemme
9、 comit dtudesLattention du lecteur est attire sur les listes figurant la finde cette publication,qui numrent les publications de laCEI prpares par le comit dtudes qui a tabli laprsente publication.Validity of this publicationThe technical content of IEC publications is kept underconstant review by t
10、he IEC,thus ensuring that the contentreflects current technology.Information relating to the date of the reconfirmation of thepublication is available from the IEC Central Office.Information on the revision work,the issue of revisededitions and amendments may be obtained from IECNational Committees
11、and from the following IECsources:IEC BulletinIEC YearbookPublished yearlyCatalogue of IEC publicationsPublished yearly with regular updatesTerminologyFor general terminology,readers are referred to IEC 50:International Electrotechnical Vocabulary(IEV),which isissued in the form of separate chapters
12、 each dealingwith a specific field.Full details of the IEV will besupplied on request.See also the IEC MultilingualDictionary.The terms and definitions contained in the present publi-cation have either been taken from the IEV or have beenspecifically approved for the purpose of this publication.Grap
13、hical and letter symbolsFor graphical symbols,and letter symbols and signsapproved by the IEC for general use,readers are referred topublications:IEC 27:Letter symbols to be used in electricaltechnology;IEC 417:Graphical symbols for use onequipment.Index,survey and compilation of thesingle sheets;I
14、EC 617:Graphical symbols for diagrams;and for medical electrical equipment,IEC 878:Graphical symbols for electromedicalequipment in medical practice.The symbols and signs contained in the present publicationhave either been taken from IEC 27,IEC 417,IEC 617and/or IEC 878,or have been specifically ap
15、proved for thepurpose of this publication.IEC publications prepared by the sametechnical committeeThe attention of readers is drawn to the end pages of thispublication which list the IEC publications issued by thetechnical committee which has prepared the presentpublication.LICENSED TO MECON Limited
16、.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.NORMEINTERNATIONALEINTERNATIONALSTANDARDCEIIEC721-3-4Deuxime ditionSecond edition1995-01Classification des conditions denvironnement Partie 3:Classification des groupements des agentsdenvironnement et de leurs svrits Section 4:Utilisation poste fixe,non protg contre les intempriesClassification of environmental conditions Part 3:Classification of groups of environmentalparameters and their severities Section