1、BRITISH STANDARD AEROSPACE SERIES BS EN 2155-5:1989 Test methods for transparent materials for aircraft glazing Part 5: Determination of visible light transmission This European Standard EN 2155-5 has the status of a British Standard. UDC 629.73.023.26:620.1:535.345.1 2BSEN2155-5:1989 This British S
2、tandard, having been prepared under the directionof the Aerospace Standards Policy Committee, waspublished under the authorityof the Board of BSI andcomes into effect on 31October1989 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference ACE/62 Draft for c
3、omment 88/70404 DC ISBN 0 580 17930 3 Cooperating organizations The European Committee for Standardization, under whose supervision this European Standard was prepared, comprises the national standards organizations of the following Western European countries. Austria Oesterreichisches Normungsinsti
4、tut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Icelandic Council for Standardizat
5、ion Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxemburg Inspection des travails et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Instituto Espaol de Norm
6、alizacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date of issue CommentsBSEN2155-5:1989 BSI 09-1999 i Contents Page Cooperating organizations Inside front co
7、ver National foreword ii Brief history 2 Text of EN 2155-5 3 National appendix A Inside back coverBSEN2155-5:1989 ii BSI 09-1999 National foreword This British Standard has been prepared under the direction of the AerospaceStandards Policy Committee and is the English language version ofEN2155 “Aero
8、space series. Test methods for transparent materials for aircraft glazing” Part5 “Determination of visible light transmission” published by the European Committee for Standardization (CEN). EN2155-5 was produced as a result of international discussion in which the UK took an active part. A British S
9、tandard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cov
10、er, an inside front cover, pages i and ii, theEN title page, pages2to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME
11、 EUROPENNE EUROPISCHE NORM EN 2155-5 March 1989 UDC: 629.73.023.26:620.1:535.345.1-2 Key words: Aircraft industry, glazing, transparent plastics, glass, test, optical properties English version Aerospace series Test methods for transparent materials foraircraftglazing Part 5: Determination of visibl
12、e light transmission Srie arospatiale Mthodes dessais pour matriaux transparents pour vitrages aronautiques Partie 5: Mesure de la transmission originale dans le visible Luft- und Raumfahrt Prfverfahren fr transparente Werkstoffe zur Verglasung vonLuftfahrzeugen Teil 5: Messung des Lichttransmission
13、s- gradesim sichtbaren Bereich This European Standard was accepted by CEN on 1988-03-17. CEN members are bound to comply with the requirements of CEN Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-
14、date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Central Secretariat 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 und
15、er the responsibility of a CEN member into its own language and notified to CEN Central Secretariat has the same status as the official versions. CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, N
16、etherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1989 Copyright reserved to all CEN members Ref. No. EN 215
17、5-5:1989 EEN2155-5:1989 BSI 09-1999 2 Brief history This European Standard has been prepared by the European Association of Aerospace Manufacturers (AECMA). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has successively received the approval of
18、 the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to CEN. According to the Common CEN/CENELEC Rules, following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland,
19、 Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Contents Page Brief history 2 1 Scope and field of application 3 2 Definitions 3 3 Apparatus 3 4 Specimens 4 5 Procedure 4 6 Expression of results 4 7 Test report 4 Figure 1 Hazemeter 5 Figur
20、e 2 Pivotable-sphere hazemeter 5EN2155-5:1989 BSI 09-1999 3 1 Scope and field of application This standard specifies the determination of visible light transmission for transparent materials by using a photometer employing a defined light source and a photocell matched to the response of the human e
21、ye. Because the materials under test are basically colourless, certain deviations from ideal conditions, indicated in the test, are allowable. 2 Definitions Visible light transmission is defined as the intensity of an emerging beam of light compared with that of the incident parallel beam falling up
22、on the specimen under examination. 3 Apparatus The apparatus shall consist of a hazemeter, constructed essentially as shown in Figure 1 or Figure 2. It consists of a stabilised light source and associated optical system, specimen holder and photometer all rigidly mounted on a convenient optical benc
23、h. The distance of the photometer from the illuminated area of the specimen shall not be less than250mm in order to avoid spurious signals from scattered light. 3.1 Light source 3.1.1 The light source is a tungsten filament lamp operated at a colour temperature of (2855 285)K. This will be attained
24、by using a gas filled tungsten filament lamp operating at its rated voltage. 3.1.2 The power supply to this lamp shall be stabilized. The short term change in voltage output shall not be more than 0,1%. 3.1.3 The light source is combined with an optical system to produce a parallel light beam of are
25、a at least1cm 2 . 3.2 Photometer This shall be a suitable photocell fitted with diffusion screen or integrating sphere. 3.2.1 The spectral response of the photocell shall be corrected to approximate that of the human eye. For practical purposes this correction may be limited to ensuring that no subs
26、tantial response exists beyond the visible band. A selenium/iron photocell with a green filter is satisfactory for this purpose. 3.2.2 The output response of the photocell shall be linear within 0,5%. 3.2.3 The output of the photocell shall be read on a suitable measuring instrument of 0,5%accuracy.
27、 3.2.4 The photocell shall be fitted with a diffusion screen and both shall be of adequate dimensions to completely cover the parallel light beam produced by the light source. 3.3 Specimen holder The specimen holder shall be such as to hold the specimen rigidly in a plane normal to the light beam. 3
28、.4 Use of integrating sphere It may be convenient to use a photometric integrating sphere in place of the photometer described in3.2. In which case the apparatus may be constructed essentially as shown in Figure 1 or Figure 2. 3.4.1 Integrating sphere An integrating sphere is used to collect transmi
29、tted flux. The sphere may be of any diameter so long as the total port area does not exceed4%of the internal reflecting area of the sphere. The entrance and exit ports shall be centred on the same great circle of the sphere and there shall be at least170 of arc between centres. The exit port shall s
30、ubtend an angle of8 at the centre of the entrance port. The axis of the irradiating beam shall pass through the centres of the entrance and exit ports. The photocell or photocells shall be positioned on the sphere (90 10) from the entrance port. In the pivotable model, Figure 2, which is designed to
31、 use the interior sphere wall adjacent to the exit port as the reflectance standard, the angle of rotation shall not exceed10 . 3.4.2 Light beam The specimen shall be illuminated by a substantially unidirectional beam; the maximum angle which any ray of this beam makes with the direction of its axis
32、 shall not exceed3 . The beam shall not be vignetted at either port of the sphere. When the beam is unobstructed by a specimen, its cross section at the exit port shall be approximately circular, sharply defined and concentric within the exit port, leaving an annulus of (1,3 0,1) subtended at the en
33、trance port. When the specimen is placed immediately against the integrating sphere at the entrance port, the angle between the normal to its surface and the axis of the beam shall not exceed8 .EN2155-5:1989 4 BSI 09-1999 3.4.3 Reflecting surfaces The surfaces of the interior of the integrating sphe
34、re, baffles and reflectance standards shall be of substantially equal reflectance, matt and highly reflecting throughout the visible wave lengths (freshly smoked magnesium oxide is excellent for this purpose but highly reflecting matt sphere paints are more durable). 3.4.4 Light trap For some measur
35、ements the standard at the exit port is replaced by a light trap by actual removal of the reflectance standard or by pivoting the sphere (see Figure 2). The light trap shall absorb the beam completely when no specimen is present. Due to the absorbing annulus surrounding the unimpeded beam at the exi
36、t port, this trap will absorb slightly more than the undeviated portion of the total flux transmitted by the specimen. 3.4.5 Photoelectric cell The radiant flux within the sphere shall be measured by a photoelectric cell, the output measurements of which shall be proportional within1%to the incident
37、 flux over the range of intensity used. Spectral conditions for source and receiver shall be constant throughout the test of each specimen. The design of the instrument shall be such that there shall be a zero reading when the sphere is dark. The spectral response of the photocell shall be corrected
38、 to approximate that of the human eye. 3.4.6 Clauses3.2.1, 3.2.2 and3.2.3 apply to the photocell used in conjunction with the integrating sphere. 4 Specimens Specimens shall be cut from sheets with the surfaces substantially flat and parallel. 5 Procedure 5.1 The specimen shall be cleaned with soapy
39、 water on both surfaces before measurements are made. 5.2 The apparatus is allowed sufficient time to reach thermal equilibrium before the measurements are made. 5.3 The measurements shall be made with the light beam normal to the surface of the specimen and the average taken from three independent
40、measurements on the one specimen. 5.4 A first reading (a) of the photometer output shall be made with the specimen outside of the beam. 5.5 A second reading (b) shall be made with the specimen interposed between the light source and photometer (specimen-photometer distance at least250mm). 5.6 The th
41、ickness of the specimen shall be measured in three places to an accuracy of0,02mm. 6 Expression of results The percentage of visible light transmission is calculated from the formula: % visible light transmission = 7 Test report The test report shall include the following: 7.1 The percentage of visi
42、ble light transmission as the average of three calculated results, 7.2 The thickness of the specimen as the arithmetic average of the three measurements. b a - 100EN2155-5:1989 BSI 09-1999 5 Figure 1 Hazemeter Figure 2 Pivotable-sphere hazemeter6 blankBSEN2155-5:1989 BSI 09-1999 National appendix A
43、The United Kingdom participation in the preparation of this European Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical Committee ACE/62upon which the following bodies were represented: British Plastics Federation Ministry of Defence Society of British Aerospace
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