1、Designation: G 154 06Standard Practice forOperating Fluorescent Light Apparatus for UV Exposure ofNonmetallic Materials1This standard is issued under the fixed designation G 154; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.NoteA footnote was added to Table X2.1, Table X2.3 was added, a new Note X2.8 was added, and the year date was changed on
3、 June 5, 2006.1. Scope1.1 This practice covers the basic principles and operatingprocedures for using fluorescent UV light, and water apparatusintended to reproduce the weathering effects that occur whenmaterials are exposed to sunlight (either direct or throughwindow glass) and moisture as rain or
4、dew in actual usage.This practice is limited to the procedures for obtaining,measuring, and controlling conditions of exposure. A numberof exposure procedures are listed in an appendix; however, thispractice does not specify the exposure conditions best suitedfor the material to be tested.NOTE 1Prac
5、tice G 151 describes performance criteria for all exposuredevices that use laboratory light sources. This practice replaces PracticeG53, which describes very specific designs for devices used for fluores-cent UV exposures. The apparatus described in Practice G53is coveredby this practice.1.2 Test sp
6、ecimens are exposed to fluorescent UV lightunder controlled environmental conditions. Different types offluorescent UV light sources are described.1.3 Specimen preparation and evaluation of the results arecovered in ASTM methods or specifications for specificmaterials. General guidance is given in P
7、ractice G 151 and ISO4892-1. More specific information about methods for deter-mining the change in properties after exposure and reportingthese results is described in ISO 4582.1.4 The values stated in SI units are to be regarded as thestandard.1.5 This standard does not purport to address all of t
8、hesafety 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.1.6 This standard is technically similar to ISO 4892-3 andISO DIS 115
9、07.2. Referenced Documents2.1 ASTM Standards:2D 3980 Practice for Interlaboratory Testing of Paint andRelated MaterialsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG53 Practice for Operating Light- and Water-ExposureApparatus (Fluorescent UV-Conden
10、sation Type) for Expo-sure of Nonmetallic MaterialsG113 Terminology Relating to Natural and ArtificialWeathering Tests for Nonmetallic MaterialsG 151 Practice for Exposing Nonmetallic Materials in Ac-celerated Test Devices That Use Laboratory Light Sources2.2 CIE Standard:CIE-Publ. No. 85: Recommend
11、ations for the IntegratedIrradiance and the Spectral Distribution of SimulatedSolar Radiation for Testing Purposes32.3 ISO Standards:ISO 4582, PlasticsDetermination of the Changes of Co-lour and Variations in Properties After Exposure to Day-light Under Glass, Natural Weathering or Artificial Light4
12、ISO 4892-1, PlasticsMethods of Exposure to LaboratoryLight Sources, Part 1, Guidance4ISO 4892-3, PlasticsMethods of Exposure to LaboratoryLight Sources, Part 3, Fluorescent UV lamps4ISO DIS 11507, Paint and VarnishesExposure of Coat-ings to Artificial Weathering in ApparatusExposure toFluorescent Ul
13、traviolet and Condensation Apparatus43. Terminology3.1 DefinitionsThe definitions given in TerminologyG113are applicable to this practice.1This practice is under the jurisdiction of ASTM Committee G03 on Weatheringand Durability and is the direct responsibility of Subcommittee G03.03 onSimulated and
14、 Controlled Exposure Tests.Current edition approved June 5, 2006. Published June 2006. Originallyapproved in 1997. Last previous edition approved in 2005 as G 154 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual B
15、ook of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Secretary, U.S. National Committee, CIE, National Institute ofStandards and Technology (NIST), Gaithersburg, MD 20899.4Available from American National Standards Institute (ANSI),
16、 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This StandardAs usedin this practice, the term sunlight is identical to the termsdaylight and solar ir
17、radiance, global as they are defined inTerminology G 113.4. Summary of Practice4.1 Specimens are exposed to repetitive cycles of light andmoisture under controlled environmental conditions.4.1.1 Moisture is usually produced by condensation ofwater vapor onto the test specimen or by spraying the spec
18、i-mens with demineralized/deionized water.4.2 The exposure condition may be varied by selection of:4.2.1 The fluorescent lamp,4.2.2 The lamps irradiance level,4.2.3 The type of moisture exposure,4.2.4 The timing of the light and moisture exposure,4.2.5 The temperature of light exposure, and4.2.6 The
19、 temperature of moisture exposure, and4.2.7 The timing of a light/dark cycle.4.3 Comparison of results obtained from specimens exposedin same model of apparatus should not be made unlessreproducibility has been established among devices for thematerial to be tested.4.4 Comparison of results obtained
20、 from specimens exposedin different models of apparatus should not be made unlesscorrelation has been established among devices for the materialto be tested.5. Significance and Use5.1 The use of this apparatus is intended to induce propertychanges associated with the end use conditions, including th
21、eeffects of the UV portion of sunlight, moisture, and heat. Theseexposures may include a means to introduce moisture to thetest specimen. Exposures are not intended to simulate thedeterioration caused by localized weather phenomena, such asatmospheric pollution, biological attack, and saltwater expo
22、-sure. Alternatively, the exposure may simulate the effects ofsunlight through window glass. Typically, these exposureswould include moisture in the form of condensing humidity.NOTE 2Caution: Refer to Practice G 151 for full cautionary guidanceapplicable to all laboratory weathering devices.5.2 Vari
23、ation in results may be expected when operatingconditions are varied within the accepted limits of this practice.Therefore, no reference shall be made to results from the use ofthis practice unless accompanied by a report detailing thespecific operating conditions in conformance with the Section10.5
24、.2.1 It is recommended that a similar material of knownperformance (a control) be exposed simultaneously with thetest specimen to provide a standard for comparative purposes.It is recommended that at least three replicates of each materialevaluated be exposed in each test to allow for statisticaleva
25、luation of results.6. Apparatus6.1 Laboratory Light SourceThe light source shall befluorescent UV lamps. A variety of fluorescent UV lamps canbe used for this procedure. Differences in lamp intensity orspectrum may cause significant differences in test results. Adetailed description of the type(s) o
26、f lamp(s) used should bestated in detail in the test report. The particular testingapplication determines which lamp should be used. See Ap-pendix X1 for lamp application guidelines.NOTE 3Do not mix different types of lamps. Mixing different types oflamps in a fluorescent UV light apparatus may prod
27、uce major inconsis-tencies in the light falling on the samples, unless the apparatus has beenspecifically designed to ensure a uniform spectral distribution.NOTE 4Many fluorescent lamps age significantly with extended use.Follow the apparatus manufacturers instructions on the procedure neces-sary to
28、 maintain desired irradiance (1,2).6.1.1 Actual irradiance levels at the test specimen surfacemay vary due to the type or manufacturer of the lamp used, orboth, the age of the lamps, the distance to the lamp array, andthe air temperature within the chamber and the ambientlaboratory temperature. Cons
29、equently, the use of a radiometerto monitor and control the radiant energy is recommended.6.1.2 Several factors can affect the spectral power distribu-tion of fluorescent UV lamps:6.1.2.1 Aging of the glass used in some types of lamps canresult in changes in transmission. Aging of glass can result i
30、na significant reduction in the short wavelength UV emission ofsome lamp types,6.1.2.2 Accumulation of dirt or other residue on lamps canaffect irradiance,6.1.2.3 Thickness of glass used for lamp tube can have largeeffects on the amount of short wavelength UV radiationtransmitted, and6.1.2.4 Uniform
31、ity and durability of phosphor coating.6.1.3 Spectral Irradiance:NOTE 5Fluorescent UVAlamps are available with a choice of spectralpower distributions that vary significantly. The more common may beidentified as UVA-340 and UVA-351. These numbers represent thecharacteristic nominal wavelength (in nm
32、) of peak emission for each ofthese lamp types. The actual peak emissions are at 343 and 350 nm,respectively.6.1.3.1 Spectral Irradiance of UVA-340 Lamps for DaylightUVThe spectral power distribution of UVA-340 fluorescentlamps shall comply with the requirements specified in Table 1.NOTE 6The main a
33、pplication for UVA-340 lamps is for simulation ofthe short and middle UV wavelength region of daylight.6.1.3.2 Spectral Irradiance of UVA-351 Lamps for DaylightUV Behind Window GlassThe spectral power distribution ofUVA-351 lamp for Daylight UV behind Window Glass shallcomply with the requirements s
34、pecified in Table 2.NOTE 7The main application for UVA-351 lamps is for simulation ofthe short and middle UV wavelength region of daylight which has beenfiltered through window glass (3).6.1.3.3 Spectral Irradiance of UVB-313 LampsThe spec-tral power distribution of UVB-313 fluorescent lamps shallco
35、mply with the requirements specified in Table 3.NOTE 8Fluorescent UVB lamps have the spectral distribution ofradiation peaking near the 313-nm mercury line. They emit significantamounts of radiation below 300 nm, the nominal cut on wavelength ofglobal solar radiation, that may result in aging proces
36、ses not occurringoutdoors. Use of this lamp is not recommended for sunlight simulation.See Table 3.G1540626.2 Test ChamberThe design of the test chamber mayvary, but it should be constructed from corrosion resistantmaterial and, in addition to the radiant source, may provide formeans of controlling
37、temperature and relative humidity. Whenrequired, provision shall be made for the spraying of water onthe test specimen for the formation of condensate on theexposed face of the specimen or for the immersion of the testspecimen in water.6.2.1 The radiant source(s) shall be located with respect tothe
38、specimens such that the uniformity of irradiance at thespecimen face complies with the requirements in PracticeG 151.6.2.2 Lamp replacement, lamp rotation, and specimen repo-sitioning may be required to obtain uniform exposure of allspecimens to UV radiation and temperature. Follow manufac-turers re
39、commendation for lamp replacement and rotation.6.3 Instrument CalibrationTo ensure standardization andaccuracy, the instruments associated with the exposure appa-ratus (for example, timers, thermometers, wet bulb sensors, drybulb sensors, humidity sensors, UV sensors, and radiometers)require periodi
40、c calibration to ensure repeatability of testresults. Whenever possible, calibration should be traceable tonational or international standards. Calibration schedule andprocedure should be in accordance with manufacturers in-structions.6.4 RadiometerThe use of a radiometer to monitor andcontrol the a
41、mount of radiant energy received at the sample isrecommended. If a radiometer is used, it shall comply with therequirements in Practice G 151.6.5 ThermometerEither insulated or un-insulated black orwhite panel thermometers may be used. The un-insulatedthermometers may be made of either steel or alum
42、inum.Thermometers shall conform to the descriptions found inPractice G 151.6.5.1 The thermometer shall be mounted on the specimenrack so that its surface is in the same relative position andsubjected to the same influences as the test specimens.6.5.2 Some specifications may require chamber air tempe
43、ra-ture control. Positioning and calibration of chamber air tem-perature sensors shall be in accordance with the descriptionsfound in Practice G 151.NOTE 9Typically, these devices control by black panel temperatureonly.6.6 MoistureThe test specimens may be exposed to mois-ture in the form of water s
44、pray, condensation, or high humidity.6.6.1 Water SprayThe test chamber may be equipped witha means to introduce intermittent water spray onto the testspecimens under specified conditions. The spray shall beTABLE 1 Relative Ultraviolet Spectral Power DistributionSpecification for Fluorescent UVA-340
45、Lamps for Daylight UVA,BSpectral BandpassWavelength l in nmMinimumPercentCBenchmark SolarRadiation PercentD,E,FMaximumPercentCl 290 0.01290 # l # 320 5.9 5.8 9.3320 l # 360 60.9 40.0 65.5360 l # 400 26.5 54.2 32.8AData in Table 1 are the irradiance in the given bandpass expressed as apercentage of t
46、he total irradiance from 290 to 400 nm. The manufacturer isresponsible for determining conformance to Table 1. Annex A1 states how todetermine relative spectral irradiance.BThe data in Table 1 are based on the rectangular integration of 65 spectralpower distributions for fluorescent UV devices opera
47、ting with UVA 340 lamps ofvarious lots and ages. The spectral power distribution data is for lamps within theaging recommendations of the device manufacturer. The minimum and maximumdata are at least the three sigma limits from the mean for all measurements.CThe minimum and maximum columns will not
48、necessarily sum to 100 %because they represent the minimum and maximum for the data used. For anyindividual spectral power distribution, the calculated percentage for the band-passes in Table 1 will sum to 100 %. For any individual fluorescent UVA-340 lamp,the calculated percentage in each bandpass
49、must fall within the minimum andmaximum limits of Table 1. Test results can be expected to differ betweenexposures using devices with fluorescent UVA-340 lamps in which the spectralpower distributions differ by as much as that allowed by the tolerances. Contact themanufacturer of the fluorescent UV devices for specific spectral power distributiondata for the fluorescent UVA-340 lamp used.DThe benchmark solar radiation data is defined in ASTM G 177 and is foratmospheric conditions and altitude chosen to maximize the fraction of shortwavelength solar UV. W
