【英文标准名称】:StandardTestMethodforMeasuringOpticalAngularDeviationofTransparentParts
【原文标准名称】:透明部件光学角度偏差的标准测量方法
【标准号】:ASTMF801-1996(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:1996
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:F07.08
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:aimingaccuracy;aimingerror;angulardeviation;deviation;refraction;Aerospacetransparentenclosures;Angulardeviation;Canopies(aerospaceapplications);Collimator/collimation;Deviation;Lateraldisplacement;Lineardisplacement;Opticalmater
【摘要】:Oneofthemeasuresofopticalqualityofatransparentpartisitsangulardeviation.Excessiveangulardeviation,orvariationsinangulardeviationthroughoutthepart,resultinvisibledistortionofscenesviewedthroughthepart.Angulardeviation,itsdetection,andquantificationareofextremeimportanceintheareaofcertainaircrafttransparencyapplications,thatis,aircraftequippedwithHeads-upDisplays(HUD).HUDsmayrequirestringentcontrolovertheopticsoftheportionofthetransparency(windscreenorcanopy)whichliesbetweentheHUDcombiningglassandtheexternalenvironment.MilitaryaircraftequippedwithHUDsorsimilardevicesrequirepreciseknowledgeoftheeffectsofthewindscreenorcanopyonimagepositioninordertomaintainweaponsaimingaccuracy.Twoopticalparametershavetheeffectofchangingimageposition.Thefirst,lateraldisplacement,isinherentinanytransparencywhichistiltedwithrespecttothelineofsight.Theeffectoflateraldisplacementisconstantoverdistance,andseldomexceedsafractionofaninch.Thesecondparameter,angulardeviation,isusuallycausedbyawedginessornonparallelismofthetransparencysurfaces.Theeffectofangulardeviationisrelatedtothetangentoftheangleofdeviation,thusthemagnitudeoftheimagepositiondisplacementincreasesasdoesthedistancebetweenimageandtransparency.Thequantificationofangulardeviationisthenthemorecriticalofthetwoparameters.1.1Thistestmethodcoversmeasuringtheangulardeviationofalightrayimposedbytransparentpartssuchasaircraftwindscreensandcanopies.Theresultsareuncontaminatedbytheeffectsoflateraldisplacement,andtheproceduremaybeperformedinarelativelyshortopticalpathlength.Thisisnotintendedasarefereestandard.Itisoneconvenientmethodformeasuringangulardeviationsthroughtransparentwindows.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A60
【国际标准分类号】:49_035
【页数】:9P.;A4
【正文语种】:英语