Designation:F733−09(Reapproved2014)StandardPracticeforOpticalDistortionandDeviationofTransparentPartsUsingtheDouble-ExposureMethod1ThisstandardisissuedunderthefixeddesignationF733;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisphotographicpracticedeterminestheopticaldis-tortionanddeviationofalineofsightthroughasimpletransparentpart,suchasacommercialaircraftwindshieldoracabinwindow.Thispracticeappliestoessentiallyflatornearlyflatpartsandmaynotbesuitableforhighlycurvedmaterials.1.2TestMethodF801addressesopticaldeviation(angluardeviation)andTestMethodF2156addressesopticaldistortionusinggridlineslope.ThesetestmethodsshouldbeusedinsteadofPracticeF733wheneverpractical.1.3Thisstandarddoesnotpurporttoaddressthesafetyconcernsassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimita-tionspriortouse.2.ReferencedDocuments2.1ASTMStandards:F801TestMethodforMeasuringOpticalAngularDeviationofTransparentPartsF2156TestMethodforMeasuringOpticalDistortioninTransparentPartsUsingGridLineSlope3.Terminology3.1Definitions:3.1.1deviation—thedisplacementofalineorobjectwhenviewedthroughthetransparentpart.Expressedastheangularmeasurementofthedisplacedline,forexample,milliradiansofangle.3.1.2distortion—therateofchangeofdeviationresultingfromanirregularityinatransparentpart.3.1.3Expressedastheangularbendingofthelightrayperunitoflengthofthepart,forexample,milliradianspercentimetre.3.1.4Mayalsobeexpressedastheslopeoftheangleoflocalizedgridlinebending,forexample,1in5(seeFig.1).3.1.5installedangle—thepartattitudeasinstalledintheaircraft.Definedbytheanglebetweenahorizontallineandtheplaneofthepart,andtheangleofsweepbackfromahorizontallinenormaltothecenterlineoftheaircraft.SeeFi...
