1、A.E.C.M.A. STANDARDNORME A.E,C.M.A.A.E.C,M.A. NORMprEN2155-7Edition 1July 1962ENGLISH VERSIONTEST METHODSFOR TRANSPARENT MATERIALSFOR AIRCRAFT GLAZINGPART 7 - DETERMINATIONOF OPTICAL DEVIATIONAEROSPACE SERIESThis Industrial standard for the aerospace sector has boon drawn up under tho responsibility
2、 of ABCMA(Association EuropOonne des Constructeurs de Materiel Aerospatlal).It is published 0/1 yollowpaper In three equivalent versIons (Bnglish, French, German).It will bo submitted to CEN (European Committee for StandardIzatIon) es a draft Buropean Standard.LUFT UND RAUMFAHRTPRUFVERFAHRENFUR TRAN
3、SPARENTE WERKSTOFFEZUR VERGLASUNG VON LUFTFAHRZEUGENTElL 7 - BESTIMMUNG DEROPTISCHEN ABLENKUNGMnHOOES OESSAISPOUR MATtRIJUX TRANSPARENTSPOUR VITflAGES MRONJUTIOUESPARTIE 7 - DnERMINATIONDE LA DtVIATION OPTIOUESRIEAtROSPATIALEtilI_Ji=I0-1t30:1/.JUIa:“f-:;:UJo(I)a:JIIIti:J0:I IJ)Zo()IJ)WClU;22ll1HI0 o
4、0:Jw2oi=jo:r:l-UiI-ClJII-.,r-Approvod blCOMITE DE NORMAl.ISATIONof A.E,C.M.A. 19811203Tho oqulvalont vorslons In ronch ond Gorman longuogoscan bo supplie.J by B,N,A.Eo, 8, rue MoroouVouth/er92100 BOULOGNEBII_LANCOURT - FRANCE. I_. .l- .L- _CONTENTS1 SCOPE AND FIELD OF APPLICATION2 DEfINITIONS3APPARA
5、TUS4SPECllvlENS5PROCEDURE6 EXPRESSION OF RESULTS7TEST REPORTprEN2155-7 Page 3A.E.C.M.A. STANDARDprEN2155-7TEST t-lETHODS FOR TRANSPARENT/YlATERIALS FOR AIRCRAFT GLAZINGPART 7 - DETERMINATION OF OPTICAL DEVIATION1 SCOPE AND FJELD OF APPLICATIONThis standal“d specifies the detennination of optical dev
6、iation causedto il bonm of light passing through a sheet of transparent materialpeppendicular to the optical axis of the system.2 DEFINITIONSOptical deviation is defined as the angular deviation of a beam ofl:lght emerging from a transparent material compared with the direct,ionof the incident beam.
7、3 APPARATUS3.1 Optical system of point light source, cross-wires, focusing lens,specimen holder and a screen.3.2 Upon the screen are traced concentric circles of specified radiisuch that thoy correspond to angles of deviation of. 1,5; j,0; 6, aand 10,0 minutes of arc relative to the distance between
8、specDlnlnd screen.3.3 The radius x of each circle for a given optical deviation inminutes is given by the fonnula :x = 0,291 d . Dwhere x radius of circle (mm)d = deviation (minutes of arc)D distance between specimen and screen (m).fhe table shows values of x corresponding to d expressed inminutes o
9、f apc and radians for two values of DrABLEd x In mm forMinutos of nrc Radians D:6m D:8m1.5 0,00043 2,2 3,53,0 0,00087 4,4 7,0G,O 0,00175 8,7 14,0-10,0 0,00291 14,5 23,34 SPECIMENSThe sp8cimens are whole sheets.5 PROCEDURE5. 1 The specimens shall be examined after carefulremovIII of surface dust.5.2
10、The optical system is set up and the image of thecross-wires is focused on to the SC1een so thatit coincides with the centre of the concentriccircles.The test specimen is interposed between cIoss-wiICSand screen at distance D from screen.5.3 The deviation is displayed as the movement of theimage fro
11、m the centle of the concentric ciIclesto one of the zones defined by the concentriccircles defined in 3.2 and 3.3.54 The specimen shall be scanned at intervals of100 mm in mutwllly perpendicular directions(unless otherwise specified).6 EXPRESSION OF RESULTSThe values of deviation as displayed (5.3) showndiagramatically so that, they may be related to theirposition on the sheet (5.4).-; TEST ImpORTThe diagfam as prepared in claus8 6 shall be recorded.
