1、BRITISH STANDARD AEROSPACE SERIES BS EN 2155-7:1997 Test methods for transparent materials for aircraft glazing Part 7: Determination of optical deviation The European Standard EN 2155-7:1997 has the status of a British Standard ICS 49.025.99; 49.045BSEN2155-7:1997 This British Standard, having been
2、 prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comesintoeffect on 15November1997 BSI 04-2000 ISBN 0 580 28133 7 National foreword This British Standard is the English language version of EN 2155-7:1997. The UK participation in
3、 its preparation was entrusted to Technical Committee ACE/62, Aerospace structural transparencies and non-reinforced plastics, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for ch
4、ange, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or
5、European 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. NOTEUnder the AECMA part numbering system, normative re
6、ferences to the Parts of AECMA-originated European Standards may appear in clause 2 in the form of a three-digit number e.g. -001 where the BSI and CEN systems would use the form -1. It can be assumed that, wherever referenced, the three-digit and single digit forms can be used interchangeably. For
7、the purposes of part-marking of components produced in accordance with this standard, the three-digit form should be used. 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 w
8、ith a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 and3 and a back cover. This standard has been updated (see copyright date) and may have had amendmen
9、ts incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN2155-7:1997 BSI 04-2000 i Contents Page National foreword Inside front cover Foreword 2 Text of EN 2155-7 3ii blankEUROPEAN STANDARD NORME EUROPENNE
10、 EUROPISCHE NORM EN 2155-7 July 1997 ICS 49.040.10; 81.040.30; 83.140 Descriptors: Aircraft industry, glazing, materials, transparency, tests, determination, optical properties, angles: geometry English version Aerospace series Test methods for transparent materialsfor aircraft glazing Part7:Determi
11、nationofoptical deviation Srie arospatiale Mthodes dessais pour matriaux transparents pour vitrages aronautiques Partie 7: Dtermination de ladviation optique Luft- und Raumfahrt Prfverfahren fr transparente Werkstoffe zur Verglasung von Luftfahrzeugen Teil 7: Bestimmung der optischen Ablenkung This
12、European Standard was approved by CEN on 1997-03-27. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references co
13、ncerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its ow
14、n language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Swe
15、den, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national
16、Members. Ref. No. EN 2155-7:1997 EEN2155-7:1997 BSI 04-2000 2 Foreword This European Standard has been prepared by the European Association of Aerospace Manufacturers (AECMA). After inquiries and votes carried out in accordance with the rules of this Association, this Standard has received the appro
17、val 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 endorsement, at the latest by January 1998, and con
18、flicting national standards shall be withdrawn at the latest by January 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, G
19、ermany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Contents Page Foreword 2 1 Scope 3 2 Definition 3 3 Apparatus 3 4 Specimens 3 5 Procedure 3 6 Expression of results 3 7 Test report 3 Table 1 3EN2155-7:1997 BSI 04-20
20、00 3 1 Scope This standard specifies the method used for the determination of optical deviation caused to a beam of light passing through a transparent element material perpendicular to the optical axis of the system. 2 Definition For the purposes of this standard, the following definition applies:
21、Optical deviation is defined as the angular deviation of a beam of light emerging from a transparent material compared with the direction of the incident beam. 3 Apparatus 3.1 Optical system of point light source, cross-wires, focusing lens, specimen holder and a screen 3.2 Upon the screen are trace
22、d concentric circles of specified radii such that they correspond to angles of deviation of 1,5; 3,0; 6,0 and 10,0 minutes of arc relative to the distance between specimen and screen. The radius r of each circle is given by the formula: r = 0,291 d.D where: The Table 1 shows values of r correspondin
23、g to d expressed in minutes of arc and radians for two values of D. Table 1 4 Specimens The specimens are the elements themselves. 5 Procedure 5.1 The specimens shall be tested after careful removal of surface dust by wiping with a lint-free cloth. 5.2 The optical system is set up so that the image
24、of the cross-wires is focused onto the screen and coincides with the centre of the concentric circles. The test specimen is interposed between the cross-wires and the screen at distance D from the screen. 5.3 The deviation is displayed as the movement of the image from the centre of the concentric c
25、ircles to one of the zones defined by the concentric circles specified in 3.2. 5.4 The specimens shall be scanned at intervals of100 mm in mutually perpendicular directions (unless otherwise specified). 6 Expression of results The values of the deviation shall be recorded and graphically represented
26、 in order to establish the relation between their position and their direction on the test specimen. 7 Test report The test report shall include the following information. number of this standard; description of the sampling method; number of test specimens used; dimensions of the test specimens use
27、d; individual values of the optical deviation and their presentation in a diagram according to 6; observations on any circumstances liable to influence the results. r is the radius of circle, in millimetres; d is the deviation, in minutes of arc; D is the distance between specimen and screen, in met
28、res. d r in mm for: Minutes of arc Radians D = 5 m D = 8 m 1,5 0,00043 2,2 3,5 3,0 0,00087 4,4 7,0 6,0 0,00175 8,7 14,0 10,0 0,00291 14,5 23,3BS EN 2155-7:1997 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing Briti
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