资源描述：
《ANSI-ISA-5.4-1991 Instrument Loop Diagrams》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、AMERICANNATIONALSTANDARDANSI/ISA–5.4–1991FormerlyANSI/ISA–S5.4–1991InstrumentLoopDiagramsApproved9September1991TMISATheInstrumentation,–Systems,andAutomationSocietyANSI/ISA-5.4-1991,InstrumentLoopDiagramsISBN1-55617-227-3Copyrightã1991bytheInstrumentSocietyofAmerica.Allri
2、ghtsreserved.PrintedintheUnitedStatesofAmerica.Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformorbyanymeans(electronic,mechanical,photocopying,recording,orotherwise),withoutthepriorwrittenpermissionofthepublisher.ISA67AlexanderDriveP.
3、O.Box12277ResearchTrianglePark,NorthCarolina27709PrefaceTheinformationcontainedinthePrefaceandForwardisforinformationonlyandisnotapartofthestandard.ThisstandardispreparedaspartoftheserviceofISAtowardagoalofuniformityinthefieldofinstrumentation.Tobeofrealvalue,thisdocument
4、shouldnotbestatic,butmustbesubjecttoperiodicreview.Towardthisend,theSocietywelcomesallcommentsandcriticisms,andrequestthattheybeaddressedtotheSecretary,StandardsandPracticesBoard,ISA,67AlexanderDrive,P.O.Box12277,ResearchTrianglePark,NC27709.Telephone(919)549-8411,e-mail:
5、standards@isa.org.TheISAStandardsandPracticesDepartmentisawareofthegrowingneedforattentiontothemetricsystemofunitsingeneralandtheInternationalSystemofUnits(SI)inparticular,inthepreparationofinstrumentationstandards.TheDepartmentisfurtherawareofthebenefitstoU.S.A.usersofIS
6、AstandardsofincorporatingsuitablereferencestotheSI(andthemetricsystem)intheirbusinessandprofessionaldealingswithothercountries.Towardthisend,thisDepartmentwilltrytointroduceSI-acceptablemetricunitsinallnewandrevisedstandardstothegreatestextentpossible.TheMetricPracticeGui
7、de,publishedbytheInstituteofElectricalandElectronicsEngineersasANSI/IEEEStd.268-1982,andfuturerevisionswillbethereferenceguidefordefinitions,symbols,abbreviations,andconversionfactors.ItisthepolicyofISAtoencourageandwelcometheparticipationofallconcernedindividualsandinter
8、estsinthedevelopmentofISAstandards.ParticipationintheISAstandards-makingprocessbyanindividualinn
