1、BS EN3475-802:2009ICS 49.06NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAerospace series Cables, electrical,aircraft use TestmethodsPart 802: Capacitance unbalance0This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommit
2、tee on 31 March2009 BSI 2009ISBN 978 0 580 62409 4Amendments/corrigenda issued since publicationDate CommentsBS EN 3475-802:2009National forewordThis British Standard is the UK implementation of EN 3475-802:2009. Itsupersedes BS EN 3475-802:2002 which is withdrawn.The UK participation in its prepara
3、tion was entrusted to TechnicalCommittee ACE/6, Aerospace 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 re
4、sponsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS EN 3475-802:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 3475-802February 2009ICS 49.060 Supersedes EN 3475-802:2002 English VersionAerospace series - Cables, electrical,
5、 aircraft use - Testmethods - Part 802: Capacitance unbalanceSrie arospatiale - Cbles lectriques usagearonautique - Mthodes dessais - Partie 802:Dsquilibre de capacitLuft- und Raumfahrt - Elektrische Leitungen frLuftfahrtverwendung - Prfverfahren - Teil 802:KapazittsdifferenzThis European Standard w
6、as approved by CEN on 11 July 2008.CEN members are bound to comply with the CEN/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 natio
7、nalstandards may be obtained on application to the CEN Management Centre or to 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 noti
8、fied to the CEN Management Centre has the same status as theofficial versions.CEN 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
9、, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, 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 exploitatio
10、n in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 3475-802:2009: EBS EN 3475-802:2009EN 3475-802:2009 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Preparation of specimens .44 Apparatus .45 Method 46 Requirement .6BS EN 3475-802:2009EN 3475-802
11、:2009 (E) 3 Foreword This document (EN 3475-802:2009) has been prepared 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 N
12、ational Associations and the Official Services of the member countries 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 August 2009, and conflicting nation
13、al standards shall be withdrawn at the latest by August 2009. Attention 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. This document supersedes
14、 EN 3475-802:2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Icelan
15、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 3475-802:2009EN 3475-802:2009 (E) 4 1 Scope This standard specifies a method for measuring the capacitance unbalance f
16、or digital data transmission cable (within a pair or quad). It shall 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, only the edition cited applies. For undated references, the
17、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 3475-801, Aerospace series Cables, electrical, aircraft use Test methods Part 801: Capacitance per unit length 3 Preparation
18、of specimens These shall be stripped and prepared for connection to the measuring device. 4 Apparatus The capacitance shall be measured with an unbalance bridge at a frequency of (1 000 100) Hz. Various types of automatic or semiautomatic equipment may also be used. 5 Method 5.1 Screened pair capaci
19、tance unbalance Capacitance shall be measured as indicated in EN 3475-801. The length of the sample shall be 3 m or more. Capacitance unbalance as a percentage shall be determined from the following formula: cbabac) (2) (4100CCCCCD+= 5.2 Screened quad capacitance unbalance pair to pair Pair to pair
20、capacitance unbalance is illustrated in Figure 1, where 1 and 2 represent the two conductors of a pair and 3 and 4 represent the two conductors of another pair. The length of the sample shall be at least 100 m or more. Capacitance unbalance pair to pair per unit of length shall be determined from th
21、e following formula: Cpp = C13+ C24 C23 C14BS EN 3475-802:2009EN 3475-802:2009 (E) 5 Use the following formula if measured length is other than 100 metres: /100LcCppCpp= where Cpp is the unbalance in picofarads corrected to 100 metres; Cpp is the unbalance of cable length (m); Lc is the cable length
22、 (m). Figure 1 5.3 Screened quad capacitance unbalance pair to ground Pair to ground capacitance unbalance is illustrated in Figure 2, where 1 and 2 represent the two conductors of a pair and 3 and 4 represent the two conductors of another pair (in case of multi pair cable, all other pairs in cable
23、shall be connected together and grounded). The length of the sample shall be at least 100 m or more. Capacitance unbalance pair to ground per unit of length shall be determined from the following formula: Cpg = C10 C20Used the following formula if measured length is other than 100 metres: )/100(LcCp
24、gCpg= where Cpg is the unbalance in picofarads corrected to 100 metres; Cpg is the unbalance of cable length (m); Lc is the cable length (m). C24C23C14213 4C13BS EN 3475-802:2009EN 3475-802:2009 (E) 6 Figure 2 6 Requirement The value obtained shall not exceed the values specified in the product stan
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