1、ASD STANDARD NORME ASD ASD NORM prEN 3475-812 Edition P 1 December 2008 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Avenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.orgICS: 49.060 Descriptors: ENGLISH
2、 VERSION Aerospace series Cables, electrical, aircraft use Test methods Part 812: Return loss (VSWR) Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 812 : Affaiblissement de rflexion Luft- und Raumfahrt Elektrische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 812: Rc
3、kflussdmpfung This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts o
4、f the concerned Domain following member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by use
5、rs and formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN t
6、he status of a national standard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 31 December 2008 Comments should be sent within six months after the date of publication to ASD-STAN Electrical Domain Copyright 2008 by ASD-STAN prEN 3475-812:2008 2
7、Contents Page Foreword2 1 Scope 3 2 Normative references 3 3 Preparation of specimens.3 4 Apparatus .3 5 Methods 3 6 Requirements.3 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After inquiries and votes carried out in accordance with the rul
8、es of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 3475-812:2008 3 1 Scope This standard specifies methods for measuring return loss (VSWR), in the required frequency bandwith of coaxial cables with characteristic impedance. The retu
9、rn loss is used for quantifying the level of the reflected signal due to the irregularity of the characteristic impedance of the cable. 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 da
10、ted references, 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
11、for test methods 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
12、 measuring device. 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 measurement 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.
