ASTM_F_1863_-_16.pdf

Designation:F186316Standard Test Method forMeasuring the Night Vision Goggle-Weighted Transmissivityof Transparent Parts1This standard is issued under the fixed designation F1863;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONTest Methods D1003 and F1316 apply to the transmissivity measurement of transparent materials,the former being for small flat samples,and the latter for any materials including larger,curved piecessuch as aircraft transparencies.Additionally,in Test Method D1003,the transmissivity is measuredperpendicular to the surface of test sample and both test methods measure only in the visible lightspectral region.Night vision goggles(NVGs)are being used in aircraft and other applications(forexample,marine navigation,driving)with increasing frequency.These devices amplify both visibleand near-infrared(NIR)spectral energy.Overall visual performance can be degraded if the observeruses the NVGs while looking through a transparency that has poor transmissivity in the visible andNIR spectral regions.This test method describes both direct and analytical measurement techniquesthat determine the NVG-weighted transmissivity of transparent pieces including ones that are large,curved,or held at the installed position.1.Scope1.1 This test method covers apparatuses and procedures thatare suitable for measuring the NVG-weighted transmissivity oftransparent parts including those that are large,thick,curved,or already installed.This test method is sensitive to transpar-encies that vary in transmissivity as a function of wavelength.1.2 Since the transmissivity(or transmission coefficient)is aratio of two radiance values,it has no units.The units ofradiance recorded in the intermediate steps of this test methodare not critical;any recognized units of radiance(for example,watts/m2-str)may be used,as long as it is consistent.21.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF1316 Test Method for Measuring the Transmissivity ofTransparent Parts3.Terminology3.1 Definitions:3.1.1 analytical test method,nthe test method that usesspectral transmissivity data of a transparent part collected bythe use of either spectrophotometric or spectroradiometricinstrumentation.The data are then examined using analyticmethods to determine the NVG-weighted transmissivity of thepart.1This test method is under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 onTransparent Enclosures and Materials.Current edition approved April 1,2016.Published April 2016.Originallyapproved in 1998.Last previous edition approved in 2010 as F1863 10.DOI:10.1520/F1863-16.2RCA Electro-Optics Handbook,RCA/Solid State Division/Electro Optics andDevices.Technical Series EOH-11.Lancaster,PA;1974.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.2 direct test method,nthe test method that uses theactual luminous output,as measured by a photometer,properlycoupled to the eyepiece of the test NVG.The NVG-weightedtransmissivity of the part is then determined by forming theratio of the NVG output luminance with the transparent part inplace to the luminance output without the part.3.1.3 NVG-weighted spectral transmissivity,nthe spectraltransmissivity of a transparent part multiplied by the spectralsensitivity of a given NVG(see Fig.1).3.1.4 NVG-weighted transmissivity(TNVG),nthe spectraltransmissivity of a transparent part multiplied by the spectralsensitivity of a given NVG integrated with respect to wave-length(see Fig.1,Eq 1 and Eq 2).3.1.5 NVG spectral sensitivity,nthe sensitivity of an NVGas a function of input wavelength.3.1.6 photometer,na device that measures luminous in-tensity or brightness by converting(weighting)the radiantintensity of an object using the relative sensitivity of the humanvisual system as defined by the photopic curve.2,43.1.7 photopic curve,nthe photopic curve is the spectralsensitivity of the human eye for daytime