1、BRITISH STANDARD AEROSPACE SERIES BS EN 3475-806:2002 Cables, electrical, aircraft use Test methods Part 806: Attenuation The European Standard EN 3475-806:2002 has the status of a British Standard ICS 49.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 3475-806:2002 T
2、his British Standard, having been prepared under the direction of the Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 25 June 2002 BSI 25 June 2002 ISBN 0 580 39908 7 National foreword This British Standard is the
3、official English language version of EN 3475-806:2002. The UK participation in its preparation was entrusted by Technical Committee ACE/6, Aerospace avionic electrical and fibre optic technology, to Subcommittee, ACE/6/2, Aerospace Cables, which has the responsibility to: A list of organizations rep
4、resented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Corres
5、pondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not
6、 of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulg
7、ate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 5 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Commen
8、tsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN3475806 June2002 ICS49.060 Englishversion AerospaceseriesCables,electrical,aircraftuseTest methodsPart806:Attenuation SriearospatialeCbleslectriquesusage aronautiqueMthodesdessaisPartie806: Affaiblissement LuftundRaumfahrtElektrischenLeitungenfrLuft
9、fahrt VerwendungPrfverfahrenTeil806:Dmpfung ThisEuropeanStandardwasapprovedbyCENon20January2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalre
10、ferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManageme
11、ntCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZAT
12、ION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN3475806:2002EEN3475806:2002(E) 2 Foreword Thisdocument(EN3475806:2002)hasbeenpreparedbythe
13、EuropeanAssociationofAerospace Manufacturers(AECMA). AfterenquiriesandvotescarriedoutinaccordancewiththerulesofthisAssociation,thisStandardhas receivedtheapprovaloftheNationalAssociationsandtheOfficialServicesofthemembercountriesof AECMA,priortoitspresentationtoCEN. ThisEuropeanStandardshallbegivent
14、hestatusofanationalstandard,eitherbypublicationofanidentical textorbyendorsement,atthelatestbyDecember2002,andconflictingnationalstandardsshallbe withdrawnatthelatestbyDecember2002. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplem
15、entthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark, Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway, Portugal,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN3475806:2002(E) 3 1 Scope Thisstandardspecifiesmethodsformeasuringtheattenuationofacable. Its
16、hallbeusedtogetherwithEN3475100. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreferenceprovisionsfromotherpublications. Thesenormativereferencesarecitedattheappropriateplacesinthetextandthepublicationsarelisted hereafter.Fordatedreferences,subsequentamendmentstoorrevisionsof
17、anyofthesepublicationsapplyto thisEuropeanStandardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthe latesteditionofthepublicationreferredtoapplies. EN3475100 AerospaceseriesCables,electrical,aircraftuseTestmethodsPart100:General 3 Preparationofspecimens Connectorsshallbefittedone
18、achendofthetestspecimens(coaxialcables)orthetestspecimensshallbe stripped(balancedcables)andconnectedtothemeasuringdevice. 4 Methods 4.1 Insertionmethod Measurementofattenuationiscarriedoutbytransmissioninharmonicmodeatthefrequenciesindicatedin theproductstandard,insertingacablesampleinasuitablecirc
19、uitandbycompensatingtheattenuation causedbythiscablebymeansofacalibratedattenuator. Thesampleshallbeofalength Lsuchthatitproduces,unlessotherwisestipulatedintheproductstandard, anattenuationequivalenttoatleast3dB. Figure1showsabasicarrangement. ThegeneratorisadjustedtothemeasuringfrequencyFanditsout
20、putlevelisheldconstantthroughout measurement. Theindicatorconsistseitherofameasurementreceiveroradetectorfollowedbyad.c.orlowfrequency voltmeterifthegeneratorismodulated. Figure1EN3475806:2002(E) 4 Theadaptordevicesshowninfigure1areintendedtoensurecorrectconnectionbetweenthemeasuringline andthecable
21、tobetested. Sincethemeasuringlineisacoaxialcable,thesedevicesshallnotbeusedifthecabletobetestedhasa coaxialstructureofthesameratedcharacteristicimpedanceastheline:theseareimpedancetransformers inthecaseofcoaxialcableswithdifferentratedcharacteristicimpedance:thesearebalancedtransformers inthecaseofs
22、ymmetricalcables(pairs). FirstnotetheoutputlevelontheindicatorwhichcorrespondstoavalueN 1 onthecalibratedvariable attenuator. Thenconnectthetestsamplebetweenaandbandreadjustthevariableattenuatorsoastoobtainthesame indicatorlevelasinthepreviousoperation;ifN 2 isthenewvalueshownonthevariableattenuator
23、, attenuationis: a = () 20 0,002 1 N N 2 1 t L + - ,indecibelspermetreat20C where tisthetemperature,indegreesCelsius,ofthetestspecimens. 4.2 Comparisonofinputandoutputvoltageorpower (insertionloss 3db) Theattenuationconstantshallbedeterminedfromtheratiooftheinputandoutputvoltageorpower.Both quantiti
24、esmaybemeasuredinturnbyasinglemeasuringreceiverorsimultaneouslywithanetworkanalyser ortwochannelpowermeters. Inthecaseofabalancedcable,themeasurementshallbecarriedoutinabalancedcondition.Ifthe measuringtestequipmentisanunbalancedone,bothendsofthepairshallbeconnectedtothetest equipmentbymeansofbaluns
25、.Thebalunsshallbeselectedtomatchthetestequipmenttothecable nominalimpedanceatthetestfrequency. Layout Thetestequipmentshallbeassembledgenerallyinaccordancewithoneofthetwocircuitarrangements showninfigure2orfigure3. Figure2LayoutoftestcircuitforcomparisonTestsetupA Where: 1 : generator 2 : attenuator
26、6dB 5 : testspecimen 6 : insertionunit 8 : terminatingload 9 : networkanalyser 10 : matchingbaluns(measurementonabalancedcablewithanunbalancedmeasuring testequipment)EN3475806:2002(E) 5 Figure3LayoutoftestcircuitforcomparisonTestsetupB Where: 1 : generator 2 : attenuator6dB 5 : testspecimen 6 : inse
27、rtionunit 7 : measuringreceiver 8 : terminatingload 9 : networkanalyser 10 : matchingbaluns(measurementonabalancedcablewithanunbalancedmeasuring testequipment) Procedure FortestsetupA,thetestcircuitshallbecalibratedatthetestfrequencywiththetestportsconnected together.Thetestspecimenshallthenbeinsert
28、edintothecircuitandtheratiooftheinputandoutputvoltage orpowershallberecorded,readingaindecibels. Expressionofresults Theattenuationconstantshallbedeterminedasfollows: TestsetupA () a = +- a 1 0,002 20 L t ,indecibelspermetreat20C TestsetupB () a = - +- aa 1 0,002 20 12 L t ,indecibelspermetreat20C W
29、here: a isthetestcircuitAreadingindecibels a 1 isthecircuitBreadingwithoutthetestspecimenindecibels a 2 isthecircuitBreadingwiththetestspecimenindecibels L isthelengthofthetestspecimeninmetres t isthetemperatureofthetestspecimenindegreesCelsius 5 Requirement Thevaluesobtainedshallnotexceedthevaluess
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