ASTM_F_520_-_10.pdf

Designation:F52010Standard Test Method forEnvironmental Resistance of Aerospace Transparencies toArtificially Induced Exposures1This standard is issued under the fixed designation F520;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers determination of the effects ofexposure to thermal shock,condensing humidity,and simu-lated weather on aerospace transparent enclosures.1.2 This test method is not recommended for quality controlnor is it intended to provide a correlation to actual service life.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 ExceptionsCertain inch-pound units are furnished inparentheses(not mandatory)and certain temperatures in Fahr-enheit associated with other standards are also furnished.1.4 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:2D1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD4329 Practice for Fluorescent UV Exposure of PlasticsF319 Practice for Polarized Light Detection of Flaws inAerospace Transparency Heating ElementsF521 Test Methods for Bond Integrity of Transparent Lami-natesF790 Guide for Testing Materials for Aerospace PlasticTransparent EnclosuresG53 Practice for Operating Light-and Water-Exposure Ap-paratus(Fluorescent UV-Condensation Type)for Expo-sure of Nonmetallic Materials(Withdrawn 2000)3G113 Terminology Relating to Natural and Artificial Weath-ering Tests of Nonmetallic MaterialsG151 Practice for Exposing Nonmetallic Materials inAccel-erated Test Devices that Use Laboratory Light SourcesG154 Practice for Operating Fluorescent LightApparatus forUV Exposure of Nonmetallic Materials3.Summary of Test Method3.1 Two types of test specimens,duplicating the aerospacetransparent enclosure design,are subjected to thermal shock,condensing humidity,and artificial weathering.Edge sealingmay be used if representative of the design.3.1.1 Type A specimens are used to determine the effect ofenvironmental exposure on electrical and optical properties.3.1.2 Type B specimens are used to determine the effect ofenvironmental exposure on bond integrity.4.Significance and Use4.1 This test method,when applied to aerospace transpar-encies of either monolithic glass/plastic or laminatedcombinations,is a measure of the ability of the transparency towithstand the effects of artificially induced environments.Thetest may be used on configurations employing electricallyconductive coatings,and also to evaluate the integrity ofnoncoated materials.4.2 The resistance of the transparent enclosure to environ-mental effects may vary appreciably depending on the size,geometry,material of construction,coating integrity,coatingdensity,and other factors.5.Test Specimens5.1 Each Type A specimen to be evaluated for externalcoating durability shall be a 250 by 250-mm(9.8 by 9.8-in.)cross section of the design and shall contain,as applicable,surface coatings of operational,electrically conducting coatingsystems complete with bus bars,braids,and temperaturesensors.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 May 1,2010.Published June 2010.Originallyapproved in 1977.Last previous edition approved in 2004 as F520 97(2004).DOI:10.1520/F0520-10.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.1 Type A test specimens shall have a fully operationalcoating system,when applicable,with an average resistivityconsistent with the average resistivity of the representativedesign.Reproduction of multiphase electrical circuits is notrequired for these test specimens since this type of circuitry isonly a design technique used to accommodate limited voltageresources at installation.5.1.2 Type A specimen testing exposure of an externalcoating only,are independent of size but shall be of sufficientsize to produce representative coatings.When testing externalcoatings the recommended specimen size is 250 by 250-mm(9.8 by 9.8-in.).Type A specimens whi