1、Designation: G 113 08Standard TerminologyRelating to Natural and Artificial Weathering Tests ofNonmetallic Materials1This standard is issued under the fixed designation G 113; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 natura
3、l 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-uctsD 40
4、23 Terminology Relating to Humidity Measurements3E41 Terminology Relating To ConditioningE 772 Terminology Relating to Solar Energy ConversionE 973 Test Method for Determination of the Spectral Mis-match Parameter Between a Photovoltaic Device and aPhotovoltaic Reference CellG84 Practice for Measure
5、ment of Time-of-Wetness onSurfaces Exposed to Wetting Conditions as inAtmosphericCorrosion TestingG90 Practice for Performing Accelerated Outdoor Weath-ering of Nonmetallic Materials Using Concentrated Natu-ral Sunlight2.2 AATCC Method:416 Colorfastness to Light2.3 ANSI Standards:5ANSI/NCSL Z540-2-1
6、997 American National Standard forExpressing UncertaintyU.S. Guide to the Expression ofUncertainty in MeasurementISO 9370 Plastics - Instrumental Determination of RadiantExposure in Weathering Tests - General Guidance andBasic Test Method3. Significance and Use3.1 This terminology is not intended to
7、 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 weathering.4. Terminology4.1 Definitions:accelerated outdoor weathering, noutdoor weathering us-ing the sun
8、 as the source of irradiance, and where the rate ofdeterioration is accelerated over that of the in-service expo-sure position increasing one or more of the influencingparameters.acceleration factor, nthe ratio of exposure time required toproduce a specified amount of change in a material by oneexpo
9、sure test divided by the exposure time required toproduce the same change by another exposure test.DISCUSSIONAcceleration factors must be used with great cautionbecause they vary between materials (including different formulationsof the same material) and are strongly dependent on the exposurecondit
10、ions and variability of both the natural and laboratory acceleratedexposures.Acceleration factors may 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 us
11、e equivalent radiant exposures to estimate timeto fail in outdoor exposures. These calculations ignore differences intemperature and moisture between the accelerated test and exteriorexposures, and in the spectral power distributions of the laboratory lightsource and sunlight.actinic radiation, nthe
12、 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 weathering, nexposure of a materialin a laboratory
13、weathering device to conditions which maybe cyclic and intensified over those encountered in outdoor1This terminology is under the jurisdiction of ASTM Committee G03 onWeathering and Durability and is the direct responsibility of Subcommittee G03.92on Terminology.Current edition approved Aug. 1, 200
14、8. Published October 2008. Originallyapproved in 1992. Last previous edition approved in 2006 as G 113 061.2For 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 stand
15、ards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from American Association of Textile Chemists and Colorists(AATCC), P.O. Box 12215, Research Triangle Park, NC 27709, http:/www.aatcc.org.5Available
16、 from National Conference of Standards Laboratories, 1800 30th St.,Suite 305B, Boulder, CO 80301.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.or in-service exposure. This involves a laboratory radiationsource, thermal stress, and
17、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.DISCUSSIONThe device may include means for control and/ormonitoring the light source and other weathering variables
18、. 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 object.backed exposure, na technique of weathering in which thetest specimens being exposed are mounted onto a
19、 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 specimen. When two materials are intimately joinedtogether to form one composite, the materials below the top
20、surface 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 unbacked.black box, na thin metal box painted flat black on theoutside only exclusive of the bottom surface with
21、 an opentop where the flat test specimens to be exposed constitute thetop surface of the box; the box is equipped with mountingstrips to hold the test specimens firmly in place; the topsurface of the box must be completely filled at all times; anyblank spaces on the top surface must be occupied by f
22、latblack “dummy” panels to maintain correct operating condi-tion.black box under glass, na glass covered enclosure orcabinet of any convenient size. It shall be constructed ofcorrosion resistant metal and be enclosed to prevent ambientair from circulating over the samples. Exterior non-glasssurfaces
23、 shall be painted black. The interior shall remainunpainted.black panel thermometer, na temperature measuring de-vice consisting of a metal panel, having a black coatingwhich absorbs all wavelengths uniformly, with a thermalsensitive element firmly attached to the center of the exposedsurface. The b
24、lack panel thermometer is used to control anartificial weathering device and to provide an estimate of themaximum temperature of samples exposed to a radiantenergy source.climatological types, nmajor regions of significantly differ-ent recurring weather patterns. In weathering, several dis-tinct cli
25、matological 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 fluctuate significantly. Thismay cause variability in short term exposures. Major cli-matic variations that ar
26、e 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 as sunny, hot,and dry year round, with rare scattered showers.control, nin weathering, the term control h
27、as three currentwidespread uses:1. A material which is of similar composition and construc-tion to the test material used for comparison, exposed at thesame time.DISCUSSIONA reference material can often be used as the control.2. A portion of the material to be tested which is stored underconditions
28、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 is protected from lightexposure by masking.DISCUSSIONThis definition is deprecated in favor of “MaskedAr
29、ea.”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 direct solar irradiance.DISCUSSIONThis definition differs from CIE (Commission Interna-tionale de lEclai
30、rage) 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 prevailing elements of theatmosphere.dry-bulb temperature, nthe temperature of the ambient air;for exampl
31、e, the temperature that is measured by thedry-bulb thermometer of a psychrometer. D 4023durability, , nin weathering, a measure of the retention oforiginal condition and function of a material after exposureto a specified set of conditions.enclosed carbon arc, na light source in which an arc isprodu
32、ced 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 whichacts to prolong the life of the carbons, and to modify thespectral power distribution received by the specimens.exposure, nthe act o
33、f 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), na specific amount of exposuremade under the conditions specified in various test methodswhere one Fading Unit is one-twent
34、ieth (120 th) of theexposure required to produce a color change equal to StepNo. 4 on the Gray Scale for Color Change or 1.7 6 0.3CIELAB units of color difference on Blue Wool Lightfast-ness Standard L 4 or 20 6 1.7 CIELAB units of colordifference on the Xenon Reference Fabric or combinationthereof.
35、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 original state.fluorescent ultraviolet lamp, va lamp in which the irradi-ance from a low pressure mercury arc is transformed
36、 to aG113082longer wavelength UV radiation by a phosphor; the spectralpower distribution of a fluorescent lamp is determined by theemission spectrum of the mercury arc light source, theemission spectrum of the phosphor and the UVtransmittanceof the glass tube.fresnel-reflector system, nflat mirrors
37、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 parabolic trough of thesame aperture angle. G90gray scale, nthe scale consists of nine pairs of standard graychips each
38、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 the difference in color represented by the scale.AATCC Technical Manualirradiance, nthe radiant power per unit area i
39、ncident on areceiver, typically reported in watts per square metre, W m2E 973masked area, na portion of the exposed specimen which isprotected from light exposure by masking. (See also con-trol.)DISCUSSIONThe mask area is not protected from heat and moisture.natural weathering, noutdoor exposure of
40、materials tounconcentrated sunlight, the purpose of which is to assessthe effects of environmental factors on various functionaland decorative parameters of interest.open flame sunshine carbon arc, na light source in whichan arc is produced across a pair of copper coated carbon rodsfilled with rare
41、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 modify the spectral power distri-bution received by the specimens.operational control point, na set point for equilibriumc
42、onditions 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 controlset point during equilibrium conditions in a laboratoryaccelerated weathering device.DISCUSSIONThe operational fluct
43、uations 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 not imply uniformity of conditions throughout the testchamber.operational uniformity, nthe range around the operatio
44、nalcontrol point for measured parameters within the intendedexposure area within the limits of intended operationalrange.DISCUSSIONIt is assumed, as with all measurements, that themeasurement of uniformity has uncertainty of measurement.photodegradation, nphotochemically induced changes inthe condit
45、ion 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 energy, diffuse radiantenergy, and reflected radiant energy from the background.E 772pyrheliometer, na radiometer used t
46、o measure the direct orbeam solar irradiance incident on a surface normal to thesuns rays. E 772radiant exposure, ntime integral of irradiance, typicallyreported in joules per square metre, J m2E 772radiometer, na general class of instruments designed todetect and measure radiant energy.reference ma
47、terial, na material with known performance.reference specimen, na portion of the reference materialthat is 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, e
48、xpressed as a percentage. E41sample, na group of units or portion of material, taken froma larger collection of units or quantity of material, whichserves to provide information that can be used as a basis foraction on the larger quantity.DISCUSSIONWhere sample is used as a term for the item to beex
49、posed, the term is deprecated in favor of specimen.solar azimuth angle, nthe angular distance measured clock-wise from due north to the projection of the beam radiationon the horizontal plane (see Fig. 1).solar irradiance, nas related to natural weathering ofmaterials, the irradiance of the sun incident on the earthssurface, having wavelengths between about 295 nm and4050 nm (4.05 microns). E 772solar irradiance, global E5(2p), nsolar irradiance receivedon an upward facing horizontal surface directly transmittedfrom t
