1、Designation: G113 14Standard TerminologyRelating to Natural and Artificial Weathering Tests ofNonmetallic Materials1This standard is issued under the fixed designation G113; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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.1. Scope1.1 This terminology standard covers terms that relate to thedurability testing of Nonmetallic Materials using natural
3、andartificial weathering exposure techniques.1.2 It is the intent of this terminology standard to includethose weathering terms in wide use in ASTM for whichstandard definitions appear desirable.2. Referenced Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood and Wood-Based Prod-uctsD4023
4、Terminology Relating to Humidity Measurements(Withdrawn 2002)3E41 Terminology Relating To ConditioningE772 Terminology of Solar Energy ConversionE973 Test Method for Determination of the Spectral Mis-match Parameter Between a Photovoltaic Device and aPhotovoltaic Reference CellG84 Practice for Measu
5、rement of Time-of-Wetness on Sur-faces Exposed to Wetting Conditions as in AtmosphericCorrosion TestingG90 Practice for Performing Accelerated Outdoor Weather-ing of Nonmetallic Materials Using Concentrated NaturalSunlightG201 Practice for Conducting Exposures in Outdoor Glass-Covered Exposure Appar
6、atus with Air Circulation2.2 AATCC Method:416 Colorfastness to Light2.3 ANSI Standards:5ANSI/NCSL Z540-2-1997 American National Standard forExpressing UncertaintyU.S. Guide to the Expression ofUncertainty in MeasurementISO 9370 Plastics - Instrumental Determination of RadiantExposure in Weathering T
7、ests - General Guidance andBasic Test Method3. Significance and Use3.1 This terminology is not intended to supersede therequirements of similar definitions in certain other documents,but is intended to provide a listing of terms that are in currentwidespread usage, and their context in relation to w
8、eathering.4. Terminology4.1 Definitions:accelerated outdoor weathering, noutdoor weathering us-ing the sun as the source of irradiance, and where the rate ofdeterioration is accelerated by increasing one or more of theinfluencing parameters above a level obtained in the naturalenvironment.DISCUSSION
9、Examples of these types of exposures are found inPractice G90 and Practice G201.acceleration factor, nthe ratio of exposure time required toproduce a specified amount of change in a material by oneexposure test divided by the exposure time required toproduce the same change by another exposure test.
10、DISCUSSIONAcceleration factors must be used with great cautionbecause they vary between materials (including different formulationsof the same material) and are strongly dependent on the exposureconditions and variability of both the natural and laboratory acceleratedexposures.Acceleration factors m
11、ay also vary depending on the level ofmaterial property change used to determine the acceleration factor. Donot ratio irradiance in laboratory accelerated tests to irradiance inoutdoor exposures, or use equivalent radiant exposures to estimate timeto fail in outdoor exposures. These calculations ign
12、ore differences intemperature and moisture between the accelerated test and exteriorexposures, and in the spectral power distributions of the laboratory lightsource and sunlight.1This terminology is under the jurisdiction of ASTM Committee G03 onWeathering and Durability and is the direct responsibi
13、lity of Subcommittee G03.92on Terminology.Current edition approved March 1, 2014. Published March 2014. Originallyapproved in 1992. Last previous edition approved in 2009 as G113 09. DOI:10.1520/G0113-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Se
14、rvice 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.4Available from American Association of Textile Chemists and Colorists(AA
15、TCC), P.O. Box 12215, Research Triangle Park, NC 27709, http:/www.aatcc.org.5Available from National Conference of Standards Laboratories, 1800 30th St.,Suite 305B, Boulder, CO 80301.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1act
16、inic radiation, nthe spectral region(s) of a light sourceresponsible for the photodegradation of a particular material.ambient temperature, nthe existing temperature of the airor of an object in thermal equilibrium with the surroundingatmosphere.artificial accelerated irradiation, nexposure of a mat
17、erialto a laboratory radiation source meant to simulate windowglass filtered solar radiation or radiation from interiorlighting sources and where specimens may be subjected torelatively small changes in temperature and relative humid-ity in an attempt to more rapidly produce the same changesthat occ
18、ur when the material is used in an indoor environ-ment.DISCUSSIONThese exposures have been commonly referred to asfading or lightfastness tests.artificial accelerated weathering, nexposure of a materialin a laboratory weathering device to conditions which maybe cyclic and intensified over those enco
19、untered in outdooror in-service exposure. This involves a laboratory radiationsource, thermal stress, and moisture (in the form of relativehumidity, and/or water spray, condensation, or immersion) inan attempt to more rapidly produce the same changes thatoccur in long term outdoor exposure.DISCUSSIO
20、NThe device may include means for control and/ormonitoring the light source and other weathering variables. It may alsoinclude exposure to special conditions, such as acid spray to simulatethe effect of industrial gases.azimuth angle, nan angle of a plane to the horizon measuredclockwise to the obje
21、ct.backed exposure, na technique of weathering in which thetest specimens being exposed are mounted onto a solidbacking material, of sufficient strength to hold the specimen.When the specimen and the backing are in direct contact thebacking material must be of a type that will not contaminatethe spe
22、cimen. When two materials are intimately joinedtogether to form one composite, the materials below the topsurface are not considered as a backing.DISCUSSIONThe backing is typically plywood which has the effectof increasing specimen temperature and wet time during exposure,compared to exposure unback
23、ed.black box, na thin metal box painted flat black on the outsideonly exclusive of the bottom surface with an open top wherethe flat test specimens to be exposed constitute the topsurface of the box; the box is equipped with mounting stripsto hold the test specimens firmly in place; the top surface
24、ofthe box must be completely filled at all times; any blankspaces on the top surface must be occupied by flat black“dummy” panels to maintain correct operating condition.black box under glass, na glass covered enclosure orcabinet of any convenient size. It shall be constructed ofcorrosion resistant
25、metal and be enclosed to prevent ambientair from circulating over the samples. Exterior non-glasssurfaces shall be painted black. The interior shall remainunpainted.black panel thermometer, na temperature measuring deviceconsisting of a metal panel, having a black coating whichabsorbs all wavelength
26、s uniformly, with a thermal sensitiveelement firmly attached to the center of the exposed surface.The black panel thermometer is used to control an artificialweathering device and to provide an estimate of the maxi-mum temperature of samples exposed to a radiant energysource.climatological types, nm
27、ajor regions of significantly differ-ent recurring weather patterns. In weathering, several dis-tinct climatological types are used to evaluate the atmo-spheric durability of materials. Within any singleclimatological variation, at a specific geographic location,short term weather patterns may fluct
28、uate significantly. Thismay cause variability in short term exposures. Major cli-matic variations that are used for the study of weathering are:warm, moist climate,subtropical climate distinguished aswarm and humid year round, with frequent rain showers.hot, dry climate,desert climate distinguished
29、as sunny, hot,and dry year round, with rare scattered showers.control, nin weathering, the term control has three currentwidespread uses:1. A material which is of similar composition and con-struction to the test material used for comparison, exposed atthe same time.DISCUSSIONA reference material ca
30、n often be used as the control.2. A portion of the material to be tested which is stored underconditions in which it is stable, and is used for comparison betweenexposed and original state.DISCUSSIONThis definition is deprecated in favor of “File Speci-men.”3. A portion of the exposed specimen which
31、 is protected from lightexposure by masking.DISCUSSIONThis definition is deprecated in favor of “MaskedArea.”daylight , nas used in weathering, the term equivalent to“sunlight”. It refers to the full spectrum of solar irradiance,that is, ultraviolet through infrared, and includes both diffusesky and
32、 direct solar irradiance.DISCUSSIONThis definition differs from CIE (Commission Interna-tionale de lEclairage) Publication No 17.4 which defines daylight as“the visible par of global (sun plus sky) radiation.direct weathering, na technique of weathering in which thetest specimens are exposed to all
33、prevailing elements of theatmosphere.dry-bulb temperature, nthe temperature of the ambient air;for example, the temperature that is measured by thedry-bulb thermometer of a psychrometer. D4023durability, nin weathering, the ability of a material tomaintain a defined property in a defined application
34、 as afunction of its end use exposure conditions and time.enclosed carbon arc, na light source in which an arc isproduced across a pair of carbon rods by a high energyelectrical source, such that a high intensity light is emitted.The carbons are enclosed in an inverted glass dome whichG113 142acts t
35、o prolong the life of the carbons, and to modify thespectral power distribution received by the specimens.exposure, nthe act of subjecting the test specimen to the testconditions.exposure angle, nthe tilt from horizontal of the test speci-men or any other exposed material, or both.fading unit (AATCC
36、), na specific amount of exposure madeunder the conditions specified in various test methods whereone Fading Unit is one-twentieth (120 th) of the exposurerequired to produce a color change equal to Step No. 4 on theGray Scale for Color Change or 1.7 6 0.3 CIELAB units ofcolor difference on Blue Woo
37、l Lightfastness Standard L 4or 20 6 1.7 CIELAB units of color difference on the XenonReference Fabric or combination thereof.AATCC Technical Manualfile specimen, nportion of the material to be tested which isstored under conditions in which it is stable, and is used forcomparison between exposed and
38、 original state.fluorescent ultraviolet lamp, va lamp in which the irradi-ance from a low pressure mercury arc is transformed to alonger wavelength UV radiation by a phosphor; the spectralpower distribution of a fluorescent lamp is determined by theemission spectrum of the mercury arc light source,
39、theemission spectrum of the phosphor and the UVtransmittanceof the glass tube.fresnel-reflector system, nflat mirrors arranged in an arraysuch that they reflect onto a target, the illuminated area ofwhich simulates the size and shape of the flat mirror. Such anarray simulates the ray-tracing of a pa
40、rabolic trough of thesame aperture angle. G90gray scale, nthe scale consists of nine pairs of standard graychips each pair representing a difference in color or contrast(shade and strength) corresponding to a numerical fastnessrating. The results of colorfastness tests are rated by visuallycomparing
41、 the difference in color represented by the scale.AATCC Technical Manualirradiance, nthe radiant power per unit area incident on areceiver, typically reported in watts per square metre, W m2E973masked area, na portion of the exposed specimen which isprotected from light exposure by masking. (See als
42、o con-trol.)DISCUSSIONThe mask area is not protected from heat and moisture.natural weathering, noutdoor exposure of materials tounconcentrated sunlight, the purpose of which is to assessthe effects of environmental factors on various functionaland decorative parameters of interest.open flame sunshi
43、ne carbon arc, na light source in whichan arc is produced across a pair of copper coated carbon rodsfilled with rare earth elements intended to produce a specificspectral power distribution. The carbons are open to theatmosphere and may be surrounded by a glass lanternarrangement which acts to modif
44、y the spectral power distri-bution received by the specimens.operational control point, na set point for equilibriumconditions measured at sensor location(s) in an exposuredevice.operational fluctuations, nThe positive and negative devia-tions from the setting of the sensor at the operational contro
45、lset point during equilibrium conditions in a laboratoryaccelerated weathering device.DISCUSSIONThe operational fluctuations are the result of unavoid-able machine variables and do not include measurement uncertainty.The operational fluctuations apply only at the location of the controlsensor and do
46、 not imply uniformity of conditions throughout the testchamber.operational uniformity, nthe range around the operationalcontrol point for measured parameters within the intendedexposure area within the limits of intended operationalrange.DISCUSSIONIt is assumed, as with all measurements, that themea
47、surement of uniformity has uncertainty of measurement.photodegradation, nphotochemically induced changes inthe condition of the material.pyranometer, na radiometer used to measure the total solarradiant energy incident upon a surface per unit time per area.This energy includes the direct radiant ene
48、rgy, diffuse radiantenergy, and reflected radiant energy from the background.E772pyrheliometer, na radiometer used to measure the direct orbeam solar irradiance incident on a surface normal to thesuns rays. E772radiant exposure, ntime integral of irradiance, typicallyreported in joules per square me
49、tre, J m2E772radiometer, na general class of instruments designed todetect and measure radiant energy.reference material, na material with known performance.reference specimen, na portion of the reference material thatis to be exposed.relative humidity, nthe ratio of the actual pressure ofexisting water vapor to the maximum possible (saturation)pressure of water vapor in the atmosphere at the sametemperature, expressed as a percentage. E41sample, na group of units or portion of material, taken froma larger collection of
