IEC_60079-3-1990_scan.pdf

79-31EC-5-INTERNATIONAL ELECTROTECHNICAL COMMISSIONELECTRICAL APPARATUS FOR EXPLOSIVE GAS ATMOSPHERESPart 3:Spark-test apparatus for intrinsically-safe circuitsFOREWORD1)The formal decisions or agreements of the IEc on technical matters,prepared by Technical Committees on which all the National Committeeshaving a special interest therein are represented,express,as nearlyas possible,an international consensus of opinion on the subjectsdealt with.2)They have the form of recommendations for international use and theyare accepted by the National Committees in that sense.3)In order to promote international unification,the IEc expresses thewish that all National Committees should adopt the text of the IECrecommendation for their national rules in so far as national con-ditions will permit.Any divergence between the IEc recommendation andthe corresponding national rules.should,as far as possible,be clearlyindicated in the latter.This part of the International Standard IEC 79 has been prepared bySub-Committee 31G:Intrinsically-safe apparatus,of IEC TechnicalCommittee No.31:Electrical apparatus for explosive atmospheres.This third edition of IEC 79-3 replaces the second edition issued in 1972.The text of this part is based on the following documents:Six MonthsRuleReports on Voting31G(C0)2331G(C0)24and24AFull information on the voting for the approval of this part can be foundin the Voting Reports indicated in the above table.This revision of the second edition embodies technical modifications,principally in clause 4,and changes in wording and presentation to takeaccount of the publication of the second edition of IEC 79-0 and the thirdedition of IEC 79-11.79-3.IEC-9-INTRODUCTIONThis part of IEC 79 applies specifically to the testing of intrinsically-safecircuits in electrical apparatus and electrical systems with type ofprotection i to show compliance with IEC 79-11.NOTE-The spark-test apparatus may also be used for testing to showcompliance with other standards when its use and calibration aredefined in those other standards.C