1、BS EN3475-812:2009ICS 49.060NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAerospace series Cables, electrical,aircraft use TestmethodsPart 812: Return loss (VSWR)This British Standardwas published underthe authority of theStandards Policy andStrategy Committee
2、 on 30September 2009 BSI 2009ISBN 978 0 580 59242 3Amendments/corrigenda issued since publicationDate CommentsBS EN 3475-812:2009National forewordThis British Standard is the UK implementation of EN 3475-812:2009.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/6, Aero
3、space avionic electrical and fibre optictechnology.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance wit
4、h a British Standard cannot confer immunityfrom legal obligations.BS EN 3475-812:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 3475-812August 2009ICS 49.060English VersionAerospace series - Cables, electrical, aircraft use - Testmethods - Part 812: Return loss (VSWR)Srie arospatiale - Cbles
5、lectriques usagearonautique - Mthodes dessais - Partie 812:Affaiblissement de rflexionLuft- und Raumfahrt - Elektrische Leitungen furLuftfahrtverwendung - Prufverfahren - Teil 812:RuckflussdampfungThis European Standard was approved by CEN on 20 June 2009.CEN members are bound to comply with the CEN
6、/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to
7、any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.C
8、EN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Swe
9、den, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref.
10、No. EN 3475-812:2009: EBS EN 3475-812:2009EN 3475-812:2009 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Preparation of specimens .4 4 Apparatus .4 5 Methods 4 6 Requirements .4 BS EN 3475-812:2009EN 3475-812:2009 (E) 3 Foreword This document (EN 3475-812:2009) has been prepare
11、d by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries
12、 of ASD, prior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2010, and conflicting national standards shall be withdrawn at the latest by February 2010. Atte
13、ntion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of
14、 the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slov
15、akia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 3475-812:2009EN 3475-812:2009 (E) 4 1 Scope This standard specifies methods for measuring return loss (VSWR), in the required frequency bandwith of coaxial cables with characteristic impedance. The return loss is used for quant
16、ifying the level of the reflected signal due to the irregularity of the characteristic impedance of the cable. It is intended to be used together with EN 3475-100. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references,
17、only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 3475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 100: General. EN 50289-1-11, Communication cables Specifications for test methods
18、 Part 1-11: Electrical test methods Characteristic impedance, input impedance, return loss. 3 Preparation of specimens The length of the test specimen shall be as specified in the product standard. Connectors shall be fitted on each end of the cable under test, to be connected to the measuring devic
19、e. To verify the adaptation of the connectors on the cable, check the VSWR of the connectors, using the temporal response (time domain). 4 Apparatus As specified in EN 50289-1-11. 5 Methods The VSWR shall be measured out in accordance with the method described in EN 50289-1-11. Perform the measureme
20、nt other the range of frequencies specified in the product standard. 6 Requirements The return loss values obtained shall not exceed the values specified in the product standard. BS EN 3475-812:2009This page has been intentionally left blank BS EN3475-812:2009BSI GroupHeadquarters 389Chiswick High R
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