1、Cables, electrical, aircraft use Test methods Part 807: Transfer impedance The European Standard EN 3475-807:2002 has the status of a British Standard ICs 49.060 BS EN 3475-80712002 WbN present to the responsible European committee any enquiries on the interpretation, or proposals for change, and ke
2、ep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or Europea
3、n publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessa
4、ry provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages
5、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. I Date I Comments O BSI 25 June 2002 ISBN O 580 39896 X EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 3475-807 June 2002 ICs 49.0
6、60 English version Aerospace series - Cables, electrical, aircraft use - Test methods - Part 807: Transfer impedance Srie arospatiale - Cbles lectriques usage aronautique - Mthodes dessais - Partie 807: Impdance de transfert Luft- und Raumfahrt - Elektrischen Leitungen fr Luftfahrt Verwendung - Prfv
7、erfahren -Teil 807: Kupplungswiderstand This European Standard was approved by CEN on 1 March 2002 CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to
8、-date lists and bibliographical references concerning such national standards may be obtained on application to the 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 translation under th
9、e responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg
10、, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Management Centre: rue de Stassart, 36 B-1050 Brussels O 2002 CEN All rights of exploitation in any form and by
11、any means reserved worldwide for CEN national Members. Ref. No. EN 3475-807:2002 E EN 3475-80712002 (E) Foreword This document (EN 3475-807:2002) has been prepared by the European Association of Aerospace Manufacturers (AECMA). After enquiries and votes carried out in accordance with the rules of th
12、is Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of AECMA, 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
13、 endorsement, at the latest by December 2002, and conflicting national standards shall be withdrawn at the latest by December 2002. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria
14、, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 2 EN 3475-80712002 (E) 1 Scope This standard specifies methods for measuring the transfer impedance of a
15、 cable. It shall be used together with EN 3475-100. 2 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For d
16、ated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 3475-100 Aerospace series - Cables, electric
17、al, aircraft use - Test methods - Part 100: General 3 Preparation of specimens These shall be stripped and prepared for connection to the measuring device required for the method chosen. 4 Methods 4.1 Simple method valid up to Method A: cable leakage method Q/m and 10 MHz - / I- 4 Matching resic tan
18、ce zo (to 1 %) - Copper box - Insulating supports - Test cable Place the length of test cable (approximately 1 m) in a sealed copper box with two lead-throughs as shown in figure 1 (dimensions 500 mm x 660 mm). The lead-throughs for the generator and microvoltmeter detector are as shown in figure 2.
19、 So that: V, = the generator voltage after the attenuator (input to cable) V = voltage detected Z, = value in ohms of characteristic impedance in common mode L = length of cable in metres; therefore: v. z, z, = - v,. L LGenerotor input L Output to microvol trne t er Figure 1 3 EN 3475-80712002 (E) _
20、-_-_-_ -_ Cable screening Cylindrical terminal end in red copper or foil 7 7,&/A I I m I For multicore cables, the two conductors shall be connected to each other at both ends. For multiscreened cables, these shall be connected to each other at both ends. Wall of the copper box Figure 2 The test cab
21、le shall be connected via its characteristic impedance Z,. Select a generator with the closest possible impedance to Z,. 4.2 Valid up to f = The conductors inside the screening, the transfer impedance of which is specified in the product standard, shall be connected together at both ends (figure 3).
22、 Method B: method of susceptible cable 30 - , where: L f is the frequency, in megahertz L is the cable length, in metres Cylindrical copper tube r Copper disc soldered to tube and to cable screening 7 Figure 3 G is a variable frequency power generator. V is a selective voltmeter (field intensity met
23、er) with input impedance ZI. The value of &A, is obtained either by direct measurement using a clamp-on current tester or by measuring UA, by the formula: R is a power limiting resistor U1 is the generator output voltage 4 EN 3475-80712002 (E) The short circuited elements are considered in the same
24、way as the conductor of a coaxial cable. See figure 4. The length of the cable inside the copper tube is L. The transfer impedance of the cable screening ZT is defined by the following theoretical formula: -66) IV.+. Figure 4 in which Vint. is the interference voltage appearing between the conductor
25、 and the screening. 5 The transfer impedance values ZT shall be below the values specified in the product standard. Req u i remen t 5 BS EN 3475-80712002 B SI 389 Chiswick High Road London w4 4AL BSI -British Standards Institution BSI is the independent national body responsible for preparing Britis
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