ASTM G154非金属材料紫外线曝光用荧光灯设备使用惯例

Designation: G 154 – 00ae1
Standard Practice for
Operating Fluorescent Light Apparatus for UV Exposure of
Nonmetallic Materials1
This standard is issued under the fixed designation G 154; the number immediay following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon （e） indicates an editorial change since the last revision or reapproval.
e1 NOTE—Table X2.2 was added editorially in August 2001.
1. Scope
1.1 This practice covers the basic principles and operating
procedures for using fluorescent UV light, and water apparatus
intended to reproduce the weathering effects that occur when
materials are exposed to sunlight （either direct or through
window glass） and moisture as rain or dew in actual usage.
This practice is limited to the procedures for obtaining,
measuring, and controlling conditions of exposure. A number
of exposure procedures are listed in an appendix; however, this
practice does not specify the exposure conditions best suited
for the material to be tested.
NOTE 1—Practice G 151 describes performance criteria for all exposure
devices that use laboratory light sources. This practice replaces Practice
G 53, which describes very specific designs for devices used for fluorescent
UV exposures. The apparatus described in Practice G 53 is covered
by this practice.
1.2 Test specimens are exposed to fluorescent UV light
under controlled environmental conditions. Different types of
fluorescent UV light sources are described.
1.3 Specimen preparation and evaluation of the results are
covered in ASTM methods or specifications for specific
materials. General guidance is given in Practice G 151 and ISO
4892-1. More specific information about methods for determining
the change in properties after exposure and reporting
these results is described in ISO 4582.
1.4 The values stated in SI units are to be regarded as the
standard.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate
safety and health practices and determine the applicability
of regulatory limitations prior to use.
1.6 This standard is technically similar to ISO 4892-3 and
ISO DIS 11507.
2. Referenced Documents
2.1 ASTM Standards:
D 3980 Practice for Interlaboratory Testing of Paint and
Related Materials2
E 691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method3
G 53 Practice for Operating Light- and Water-Exposure
Apparatus （Fluorescent UV-Condensation Type） for Exposure
of Nonmetallic Materials4
G 113 Terminology Relating to Natural and Artificial
Weathering Tests for Nonmetallic Materials4
G 151 Practice for Exposing Nonmetallic Materials in Accelerated
Test Devices That Use Laboratory Light
Sources4
2.2 CIE Standard:
CIE-Publ. No. 85: Recommendations for the Integrated
Irradiance and the Spectral Distribution of Simulated
Solar Radiation for Testing Purposes5
2.3 ISO Standards:
ISO 4582, Plastics—Determination of the Changes of Colour
and Variations in Properties After Exposure to Daylight
Under Glass, Natural Weathering or Artificial Light6
ISO 4892-1, Plastics—Methods of Exposure to Laboratory
Light Sources, Part 1, Guidance6
ISO 4892-3, Plastics—Methods of Exposure to Laboratory
Light Sources, Part 3, Fluorescent UV lamps6
ISO DIS 11507, Paint and Varnishes—Exposure of Coatings
to Artificial Weathering in Apparatus—Exposure to
Fluorescent Ultraviolet and Condensation Apparatus6
3. Terminology
3.1 Definitions—The definitions given in Terminology
G 113 are applicable to this practice.
3.2 Definitions of Terms Specific to This Standard—As used
in this practice, the term sunlight is identical to the terms
daylight and solar irradiance, global as they are defined in
Terminology G 113.
1 This practice is under the jurisdiction of ASTM Committee G3 on Weathering
and Durability and is the direct responsibility of Subcommittee G03.03 on
Simulated and Controlled Exposure Tests.
Current edition approved June 10, 2000. Published September 2000. Originally
published as G 154 – 97. Last previous edition G 154 – 00.
2 Discontinued 1998. See 1998 Annual Book of ASTM Standards, Vol 06.01.
3 Annual Book of ASTM Standards, Vol 14.02.
4 Annual Book of ASTM Standards, Vol 14.04.
5 Available from Secretary, U.S. National Committee, CIE, National Institute of
Standards and Technology （NIST）, Gaithersburg, MD 20899.
6 Available from American National Standards Institute, 11 W. 42nd St., 13th
Floor, New York, NY 10036.
4. Summary of Practice
4.1 Specimens are exposed to repetitive cycles of light and
moisture under controlled environmental conditions.
4.1.1 Moisture is usually produced by condensation of
water vapor onto the test specimen or by spraying the specimens
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 lamp’s 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, and
4.2.6 The temperature of moisture exposure, and
4.2.7 The timing of a light/dark cycle.
4.3 Comparison of results obtained from specimens exposed
in same model of apparatus should not be made unless
reproducibility has been established among devices for the
material to be tested.
4.4 Comparison of results obtained from specimens exposed
in different models of apparatus should not be made unless
correlation has been established among devices for the material
to be tested.
5. Significance and Use
5.1 The use of this apparatus is intended to induce property
changes associated with the end use conditions, including the
effects of the UV portion of sunlight, moisture, and heat. These
exposures may include a means to introduce moisture to the
test specimen. Exposures are not intended to simulate the
deterioration caused by localized weather phenomena, such as
atmospheric pollution, biological attack, and saltwater exposure.
Alternatively, the exposure may simulate the effects of
sunlight through window glass. Typically, these exposures
would include moisture in the form of condensing humidity.
NOTE 2—Caution: Refer to Practice G 151 for full cautionary guidance
applicable to all laboratory weathering devices.
5.2 Variation in results may be expected when operating
conditions are varied within the accepted limits of this practice.
Therefore, no reference shall be made to results from the use of
this practice unless accompanied by a report detailing the
specific operating conditions in conformance with the Section
10.
5.2.1 It is recommended that a similar material of known
performance （a control） be exposed simultaneously with the
test specimen to provide a standard for comparative purposes.
It is recommended that at least three replicates of each material
evaluated be exposed in each test to allow for statistical
evaluation of results.
6. Apparatus
6.1 Laboratory Light Source—The light source shall be
fluorescent UV lamps. A variety of fluorescent UV lamps can
be used for this procedure. Differences in lamp intensity or
spectrum may cause significant differences in test results. A
detailed description of the type（s） of lamp（s） used should be
stated in detail in the test report. The particular testing
application determines which lamp should be used. See Appendix
X1 for lamp application guidelines.
NOTE 3—Do not mix different types of lamps. Mixing different types of
lamps in a fluorescent UV light apparatus may produce major inconsistencies
in the light falling on the samples, unless the apparatus has been
specifically designed to ensure a uniform spectral distribution.
NOTE 4—Many fluorescent lamps age significantly with extended use.
Follow the apparatus manufacturer’s instructions on the procedure necessary
to maintain desired irradiance （1,2）.
6.1.1 Actual irradiance levels at the test specimen surface
may vary due to the type or manufacturer of the lamp used, or
both, the age of the lamps, the distance to the lamp array, and
the air temperature within the chamber and the ambient
laboratory temperature. Consequently, the use of a radiometer
to monitor and control the radiant energy is recommended.
6.1.2 Several factors can affect the spectral power distribution
of fluorescent UV lamps:
6.1.2.1 Aging of the glass used in some types of lamps can
result in changes in transmission. Aging of glass can result in
a significant reduction in the short wavelength UV emission of
some lamp types,
6.1.2.2 Accumulation of dirt or other residue on lamps can
affect irradiance,
6.1.2.3 Thickness of glass used for lamp tube can have large
effects on the amount of short wavelength UV radiation
transmitted, and
6.1.2.4 Uniformity and durability of phosphor coating.
6.1.3 Spectral Irradiance:
NOTE 5—Fluorescent UVAlamps are available with a choice of spectral
power distributions that vary significantly. The more common may be
identified as UVA-340 and UVA-351. These numbers represent the
characteristic nominal wavelength （in nm） of peak emission for each of
these lamp types. The actual peak emissions are at 343 and 350 nm,
respectively.
6.1.3.1 Spectral Irradiance of UVA-340 Lamps for Daylight
UV—The spectral power distribution of UVA-340 fluorescent
lamps shall comply with the requirements specified in Table 1.
NOTE 6—The main application for UVA-340 lamps is for simulation of
the short and middle UV wavelength region of daylight.
6.1.3.2 Spectral Irradiance of UVA-351 Lamps for Daylight
UV Behind Window Glass—The spectral power distribution of
UVA-351 lamp for Daylight UV behind Window Glass shall
comply with the requirements specified in Table 2.
NOTE 7—The main application for UVA-351 lamps is for simulation of
the short and middle UV wavelength region of daylight which has been
filtered through window glass （3）.
6.1.3.3 Spectral Irradiance of UVB-313 Lamps—The spectral
power distribution of UVB-313 fluorescent lamps shall
comply with the requirements specified in Table 2.
NOTE 8—Fluorescent UVB lamps have the spectral distribution of
radiation peaking near the 313-nm mercury line. They emit significant
amounts of radiation below 300 nm, the nominal cut on wavelength of
global solar radiation, that may result in aging processes not occurring
outdoors. Use of this lamp is not recommended for sunlight simulation.
See Table 3.
6.2 Test Chamber—The design of the test chamber may
vary, but it should be constructed from corrosion resistant
material and, in addition to the radiant source, may provide for
means of controlling temperature and relative humidity. When
required, provision shall be made for the spraying of water on
the test specimen for the formation of condensate on the
exposed face of the specimen or for the immersion of the test
specimen in water.
6.2.1 The radiant source（s） shall be located with respect to
the specimens such that the uniformity of irradiance at the
specimen face complies with the requirements in Practice
G 151.
6.2.2 Lamp replacement, lamp rotation, and specimen repositioning
may be required to obtain uniform exposure of all
specimens to UV radiation and temperature. Follow manufacturer’s
recommendation for lamp replacement and rotation.
6.3 Instrument Calibration—To ensure standardization and
accuracy, the instruments associated with the exposure apparatus
（for example, timers, thermometers, wet bulb sensors, dry
bulb sensors, humidity sensors, UV sensors, and radiometers）
require periodic calibration to ensure repeatability of test
results. Whenever possible, calibration should be traceable to
national or international standards. Calibration schedule and
procedure should be in accordance with manufacturer’s instructions.
6.4 Radiometer—The use of a radiometer to monitor and
control the amount of radiant energy received at the sample is
recommended. If a radiometer is used, it shall comply with the
requirements in Practice G 151.
6.5 Thermometer—Either insulated or un-insulated black or
white panel thermometers may be used. The un-insulated
thermometers may be made of either steel or aluminum.
Thermometers shall conform to the descriptions found in
Practice G 151.
6.5.1 The thermometer shall be mounted on the specimen
rack so that its surface is in the same relative position and
subjected to the same influences as the test specimens.
6.5.2 Some specifications may require chamber air temperature
control. Positioning and calibration of chamber air temperature
sensors shall be in accordance with the descriptions
found in Practice G 151.
NOTE 9—Typically, these devices control by black panel temperature
only.
6.6 Moisture—The test specimens may be exposed to moisture
in the form of water spray, condensation, or high humidity.
6.6.1 Water Spray—The test chamber may be equipped with
a means to introduce intermittent water spray onto the test
specimens under specified conditions. The spray shall be
uniformly distributed over the samples. The spray system shall
be made from corrosion resistant materials that do not contaminate
the water used.
6.6.1.1 Spray Water Quality—Spray water shall have a
conductivity below 5 μS/cm, contain less than 1-ppm solids,
and leave no observable stains or deposits on the specimens.
TABLE 1 Relative Spectral Power Distribution Specification for
UVA-340 Lamps for Daylight UV
Bandpass, nm Fluorescent UVA-340 LampA SunlightB
Ultraviolet Wavelength Region
Irradiance as a percentage of total irradiance from 260 to 400 nm
260–270 0.0 % 0
271–280 0.0 % 0
281–290 0.0 % 0
291–300 < 0.2 % 0
301–320 6.2–8.6 % 5.6 %
321–340 27.1–30.7 % 18.5 %
341–360 34.2–35.4 % 21.7 %
361–380 19.5–23.7 % 26.6 %
381–400 6.6–7.8 % 27.6 %
Ultraviolet and Visible Wavelength Region
Irradiance as a percentage of total irradiance from 300 to 800 nmC
300–400 87.3 %D 11 %E
401–700 12.7 %D 72 %E
AUVA-340 data—The ranges given are based on spectral power distribution
measurements made for lamps of different ages and operating at different levels of
controlled irradiance. The ranges given are based on three sigma limits from the
averages of this data.
BSunlight data—The sunlight data is for global irradiance on a horizontal surface
with a air mass of 1.2, column ozone 0.294 atm cm, 30 % relative humidity, altitude
2100 m （atmopsheric pressure of 787.8 mb）, and an aerosol represented by an
optical thickness of 0.81 at 300 nm and 0.62 at 400 nm.
CData from 701 to 800 nm is not shown.
DUVA-340 data—Because the primary emission of fluorescent UV lamps is
concentrated in the 300- to 400-nm bandpass, there are limited data available for
visible light emissions of fluorescent UV lamps. Therefore, the data in this table are
based on very few measurements and are representative only.
ESunlight data—The sunlight data is from Table 4 of CIE Publication Number 85,
global solar irradiance on a horizontal surface with an air mass of 1.0, column
ozone of 0.34 atm cm, 1.42-cm precipitable water vapor, and an aerosol
represented by an optical thickness of 0.1 at 500 nm.
TABLE 2 Relative Spectral Power Distribution Specification for
UVA-351 Lamps for Daylight UV Behind Window Glass
Bandpass, nm Fluorescent UVA-351 LampA Estimated Window Glass
Filtered SunlightB
Ultraviolet Wavelength Region
Irradiance as a percentage of total irradiance from 260 to 400 nm
260–270 0.0 % 0 %
271–280 0.0 % 0 %
281–290 0.0 % 0 %
290–300 < 0.1 % 0 %
301–320 0.9–3.3 % 0.1–1.5 %
321–340 18.3–22.7 % 9.4–14.8 %
341–360 42.7–44.5 % 23.2–23.5 %
361–380 24.8–28.2 % 29.6–32.5 %
381–400 5.8–7.6 % 30.9 –34.5 %
Ultraviolet and Visible Wavelength Region
Irradiance as a percentage of total irradiance from 300 to 800 nmC
300–400 90.1 %D 9.0–11.1 %E
401–700 9.9 %D 71.3–73.1 %E
AUVA-351 data—The ranges given are based on spectral power distribution
measurements made for lamps of different ages and operating at different levels of
controlled irradiance. The ranges given are based on three sigma limits from the
averages of this data.
BSunlight data—The sunlight data is for global irradiance on a horizontal surface
with an air mass of 1.2, column ozone 0.294 atm cm, 30 % relative humidity,
altitude 2100 m （atmospheric pressure of 787.8 mb）, and an aerosol represented
by an optical thickness of 0.081 at 300 nm and 0.62 at 400 nm. The range is
determined by multiplying solar irradiance by the upper and lower limits for
transmission of single strength window glass samples used for studies conducted
by ASTM Subcommittee G03.02.
CData from 701 to 800 nm is not shown.
DUVA-351 data—Because the primary emission of fluorescent UV lamps is
concentrated in the 300- to 400-nm bandpass, there are limited data available for
visible light emissions of fluorescent UV lamps. Therefore, the data in this table are
based on very few measurements and are representative only.
ESunlight data—The sunlight data is from Table 4 of CIE Publication Number 85,
global solar irradiance on a horizontal surface with an air mass of 1.0, column
ozone of 0.34 atm cm, 1.42-cm precipitable water vapor, and an aerosol
represented by an optical thickness of 0.1 at 500 nm. The range is determined by
multiplying solar irradiance by the upper and lower limits for transmission of single
strength window glass samples used for studies conducted by ASTM Subcommittee
G03.02.
Very low levels of silica in spray water can cause significant
deposits on the surface of test specimens. Care should be taken
to keep silica levels below 0.1 ppm. In addition to distillation,
a combination of deionization and reverse osmosis can effectively
produce water of the required quality. The pH of the
water used should be reported. See Practice G 151 for detailed
water quality instructions.
6.6.2 Condensation—The test chamber may be equipped
with a means to cause condensation to form on the exposed
face of the test specimen. Typically, water vapor shall be
generated by heating water and filling the chamber with hot
vapor, which then is made to condense on the test specimens.
6.6.3 Relative Humidity—The test chamber may be
equipped with a means to measure and control the relative
humidity. Such instruments shall be shielded from the lamp
radiation.
6.7 Specimen Holders—Holders for test specimens shall be
made from corrosion resistant materials that will not affect the
test results. Corrosion resistant alloys of aluminium or stainless
steel have been found acceptable. Brass, steel, or copper shall
not be used in the vicinity of the test specimens.
6.8 Apparatus to Assess Changes in Properties—The necessary
apparatus required by ASTM or ISO relating to the
determination of the properties chosen for monitoring shall be
used （see also ISO 4582）.
7. Test Specimen
7.1 Refer to Practice G 151.
8. Test Conditions
8.1 Any exposure conditions may be used as long as the
exact conditions are detailed in the report. Appendix X2 shows
some representative exposure conditions. These are not necessarily
preferred and no recommendation is implied. These
conditions are provided for reference only.
9. Procedure
9.1 Identify each test specimen by suitable indelible marking,
but not on areas used in testing.
9.2 Determine which property of the test specimens will be
evaluated. Prior to exposing the specimens, quantify the
appropriate properties in accordance with recognized ASTM or
international standards. If required （for example, destructive
testing）, use unexposed file specimens to quantify the property.
See ISO 4582 for detailed guidance.
9.3 Mounting of Test Specimens—Attach the specimens to
the specimen holders in the equipment in such a manner that
the specimens are not subject to any applied stress. To assure
uniform exposure conditions, fill all of the spaces, using blank
panels of corrosion resistant material if necessary.
NOTE 10—Evaluation of color and appearance changes of exposed
materials shall be made based on comparisons to unexposed specimens of
the same material which have been stored in the dark. Masking or
shielding the face of test specimens with an opaque cover for the purpose
of showing the effects of exposure on one panel is not recommended.
Misleading results may be obtained by this method, since the masked
portion of the specimen is still exposed to temperature and humidity that
in many cases will affect results.
9.4 Exposure to Test Conditions—Program the selected test
conditions to operate continuously throughout the required
number of repetitive cycles. Maintain these conditions
throughout the exposure. Interruptions to service the apparatus
and to inspect specimens shall be minimized.
9.5 Specimen Repositioning—Periodic repositioning of the
specimens during exposure is not necessary if the irradiance at
the positions farthest from the center of the specimen area is at
least 90 % of that measured at the center of the exposure area.
Irradiance uniformity shall be determined in accordance with
Practice G 151.
9.5.1 If irradiance at positions farther from the center of the
exposure area is between 70 and 90 % of that measured at the
center, one of the following three techniques shall be used for
specimen placement.
9.5.1.1 Periodically reposition specimens during the exposure
period to ensure that each receives an equal amount of
radiant exposure. The repositioning schedule shall be agreed
upon by all interested parties.
9.5.1.2 Place specimens only in the exposure area where the
irradiance is at least 90 % of the maximum irradiance.
9.5.1.3 To compensate for test variability randomly position
replicate specimens within the exposure area which meets the
irradiance uniformity requirements as defined in 9.5.1.
9.6 Inspection—If it is necessary to remove a test specimen
for periodic inspection, take care not to handle or disturb the
test surface. After inspection, the test specimen shall be
TABLE 3 Relative Spectral Power Distribution Specification for
UVB-313 Lamps
Bandpass, nm Fluorescent UVB-313 LampAB SunlightC
Ultraviolet Wavelength RegionA
Irradiance as a percentage of total irradiance from 260 to 400 nm
260–270 < 0.1 % 0
271–280 0.1–0.7 % 0
281–290 3.2–4.4 % 0
291–300 10.7–13.7 % 0
301–320 38.0–44.6 % 5.6 %
321–340 25.5–30.9 % 18.5 %
341–360 7.7–10.7 % 21.7 %
361–380 2.5–5.5 % 26.6 %
381–400 0.0–1.5 % 27.6 %
Ultraviolet and Visible Wavelength Region
Irradiance as a percentage of total irradiance from 300 to 800 nmD
300–400 88.5 %E 11 %F
401–700 11.5 %E 72 %F
AUVB-313 data—Some UVB lamps have measurable emittance at the 254-nm
mercury line. This may affect test results for some materials.
BUVB-313 data—The ranges given are based on spectral power distribution
measurements made for lamps of a different ages and operating at different levels
of controlled irradiance. The ranges given are based on three sigma limits from the
averages of this data. Lamps that meet this specification are available from
different manufacturers. These lamps may have significantly different irradiance
levels （that is, total light output）, but still have the same relative spectral power
distribution.
CSunlight data—The sunlight data in for global irradiance on a horizontal surface
with a air mass of 1.2, column ozone 0.294 atm cm, 30 % relative humidity, altitude
2100 m （atmospheric pressure of 787.8 mb）, and an aerosol represented by an
optical thickness of 0.081 to 300 nm and 0.62 at 400 nm.
DData from 701 to 800 nm is not shown.
EUVB-313 data—Because the primary emission of fluorescent UV lamps is
concentrated in the 300- to 400-nm bandpass, there is limited data available for
visible light emissions of fluorescent UV lamps. Therefore, the data in this table are
based on very low measurements and are representative only.
FSunlight data—The sunlight data is from Table 4 of CIE Publication Number 85,
global solar irradiance on a horizontal surface with an air mass of 1.0, column
ozone of 0.34 atm cm, 1.42-cm precipitable water vapor, and an aerosol
represented by an optical thickness of 0.1 at 500 nm.
returned to the test chamber with its test surface in the same
orientation as previously tested.
9.7 Apparatus Maintenance—The test apparatus requires
periodic maintenance to maintain uniform exposure conditions.
Perform required maintenance and calibration in accordance
with manufacturer’s instructions.
9.8 Expose the test specimens for the specified period of
exposure. See Practice G 151 for further guidance.
9.9 At the end of the exposure, quantify the appropriate
properties in accordance with recognized ASTM or international
standards and report the results in conformance with
Practice G 151.
NOTE 11—Periods of exposure and evaluation of test results are
addressed in Practice G 151.
10. Report
10.1 The test report shall conform to Practice G 151.
11. Precision and Bias
11.1 Precision:
11.1.1 The repeatability and reproducibility of results obtained
in exposures conducted according to this practice will
vary with the materials being tested, the material property
being measured, and the specific test conditions and cycles that
are used. In round-robin studies conducted by Subcommittee
G03.03, the 60° gloss values of replicate PVC tape specimens
exposed in different laboratories using identical test devices
and exposure cycles showed significant variability （3）. The
variability shown in these round-robin studies restricts the use
of “absolute specifications” such as requiring a specific property
level after a specific exposure period （4,5）.
11.1.2 If a standard or specification for general use requires
a definite property level after a specific time or radiant
exposure in an exposure test conducted according to this
practice, the specified property level shall be based on results
obtained in a round-robin that takes into consideration the
variability due to the exposure and the test method used to
measure the property of interest. The round-robin shall be
conducted according to Practice E 691 or Practice D 3980 and
shall include a statistically representative sample of all laboratories
or organizations that would normally conduct the
exposure and property measurement.
11.1.3 If a standard or specification for use between two or
three parties requires a definite property level after a specific
time or radiant exposure in an exposure test conducted according
to this practice, the specified property level shall be based
on statistical analysis of results from at least two separate,
independent exposures in each laboratory. The design of the
experiment used to determine the specification shall take into
consideration the variability due to the exposure and the test
method used to measure the property of interest.
11.1.4 The round-robin studies cited in 11.1.1 demonstrated
that the gloss values for a series of materials could be ranked
with a high level of reproducibility between laboratories. When
reproducibility in results from an exposure test conducted
according to this practice have not been established through
round-robin testing, performance requirements for materials
shall be specified in terms of comparison （ranked） to a control
material. The control specimens shall be exposed simultaneously
with the test specimen（s） in the same device. The
specific control material used shall be agreed upon by the
concerned parties. Expose replicates of the test specimen and
the control specimen so that statistically significant performance
differences can be determined.
11.2 Bias—Bias can not be determined because no acceptable
standard weathering reference materials are available.
12. Keywords
12.1 accelerated; accelerated weathering; durability; exposure;
fluorescent UV lamps; laboratory weathering; light;
lightfastness; non-metallic materials; temperature; ultraviolet;
weathering
APPENDIXES
（Nonmandatory Information）
X1. APPLICATION GUIDELINES FOR TYPICAL FLUORESCENT UV LAMPS
X1.1 General
X1.1.1 A variety of fluorescent UV lamps may be used in
this practice. The lamps shown in this section are representative
of their type. Other lamps, or combinations of lamps, may
be used. The particular application determines which lamp
should be used. The lamps discussed in this Appendix differ in
the total amount of UV energy emitted and their wavelength
spectrum. Differences in lamp energy or spectrum may cause
significant differences in test results. A detailed description of
the type（s） of lamp（s） used shall be stated in detail in the test
report.
X1.1.2 All spectral power distributions （SPDs） shown in
this section are representative only and are not meant to be
used to calculate or estimate total radiant exposure for tests in
fluorescent UV devices. Actual irradiance levels at the test
specimen surface will vary due to the type and/or manufacturer
of the lamp used, the age of the lamps, the distance to the lamp
array, and the air temperature within the chamber.
NOTE X1.1—All SPDs in this appendix were measured using a spectroradiometer
with a double grating monochromator （1-nm band pass）
with a quartz cosine receptor. The fluorescent UV SPDs were measured at
the sample plane in the center of the allowed sample area. SPDs for
sunlight were measured in Phoenix, AZ at solar noon at the summer
solstice with a clear sky, with the spectroradiometer on an equatorial
follow-the-sum mount.
X1.2 Simulations of Direct Solar UV Radiation Exposures
X1.2.1 UVA-340 Lamps—For simulations of direct solar
UV radiation the UVA-340 lamp is recommended. Because
UVA-340 lamps typically have little or no UV output below
300 nm （that is considered the “cut-on” wavelength for
terrestrial sunlight）, they usually do not degrade materials as
rapidly as UVB lamps, but they may allow enhanced correlation
with actual outdoor weathering. Tests using UVA-340
lamps have been found useful for comparing different nonmetallic
materials such as polymers, textiles, and UV stabilizers.
Fig. X1.1 illustrates the SPD of the UVA-340 lamp compared
to noon, summer sunlight.
X1.2.2 UVB-313 Lamps—The UVB region （280 to 315 nm）
includes the shortest wavelengths found in sunlight at the
earth’s surface and is responsible for considerable polymer
damage. There are two commonly available types of UVB-313
lamps that meet the requirements of this document. These are
known commercially as the UVB-313 and the FS-40. These
lamps emit different amounts of total energy, but both peak at
313 nm and produce the same UV wavelengths in the same
relative proportions. In tests using the same cycles and temperatures,
shorter times to failure are typically observed when
the lamp with higher UV irradiance is used. Furthermore, tests
using the same cycles and temperatures with these two lamps
may exhibit differences in ranking of materials due to difference
in the proportion of UV to moisture and temperature.
NOTE X1.2—The Fig. X1.2 illustrates the difference between the lamps.
X1.2.2.1 All UVB-313 lamps emit UV below the normal
sunlight cut-on. This short wavelength UV can produce rapid
polymer degradation and often causes degradation by mechanisms
that do not occur when materials are exposed to sunlight.
This may lead to anomalous results. Fig. X1.2 shows the
spectral power distribution （SPD） of typical UVB-313 lamps
compared to the SPD of noon, summer sunlight.
X1.3 Simulations of Exposures to Solar UV Radiation
Through Window Glass
X1.3.1 Filtering Effect of Glass
Glass of any type acts as a filter on the sunlight spectrum
（see Fig. X1.3）. Ordinary glass is essentially transparent to
light above about 370 nm. However, the filtering effect
becomes more pronounced with decreasing wavelength. The
shorter, more damaging UVB wavelengths are the most greatly
affected. Window glass filters out most of the wavelengths
below about 310 nm. For purposes of illustration, only one type
of window glass is used in the accompanying graphs. Note that
glass transmission characteristics will vary due to manufacturer,
production lot, thickness, or other factors.
X1.3.2 UVA-351 Lamps
For simulations of sunlight through window glass, UVA-351
lamps are recommended. The UVA-351 is used for these
applications because the low end cut-on of this lamp is similar
to that of direct sunlight which has been filtered through
window glass （Fig. X1.4）.
NOTE X1.3—UVB-313 lamps are not recommended for simulations of
sunlight through window glass. Most of the emission of UVB-313 lamps
is in the short wavelength UV that is filtered very efficiently by glass.
Because of this, very little energy from this short wavelength region will
reach materials in “behind glass” applications. This is because window
glass filters out about 80 % of the energy from UVB-313 lamps, as shown
in Fig. X1.5. As a result of filtering out these short wavelengths, its total
effective energy is very limited. Further, because there is little longer
wavelength energy, the glass-filtered UVB-313 is actually less severe than
a UVA Lamp.
FIG. X1.1 Spectral Power Distributions of UVA-340 Lamp and
Sunlight
FIG. X1.2 Spectral Power Distributions of UVB Lamps and
Sunlight
FIG. X1.3 Direct Sunlight and Sunlight Through Window Glass
X1.4 Simulations of Exposures Where Glass or Transparent
Plastic Forms Part of the Test Specimen
X1.4.1 UVA-340 Lamps
In some instances （for example, window sealants）, glass or
transparent plastic is part of the test specimen itself and
normally acts as a filter to the light source. In these special
cases, the use of UVA-340 lamps is recommended since the
glass or plastic will filter the spectrum of the lamp in the same
way that it would filter sunlight. Fig. X1.6 compares the
spectral power distribution of sunlight filtered through window
glass to the spectral power distribution of the UVA-340 lamp,
both unfiltered and filtered through window glass.
NOTE X1.4—UBV-313 lamps are lamps not recommended for exposures
where glass or transparent plastic forms part of the test specimen.
See Note X1.3.
NOTE X1.5—UVA-351 lamps are not recommended for exposures
where glass or transparent plastic forms part of the test specimen. This is
because the UVA-351 has a special power distribution in the short wave
UV region that is similar to sunlight that has already been filtered by
window glass. As shown in Fig. X1.7, using this lamp through window
glass or other transparent material further filters out the short wavelength
UV and results in a spectrum that is deficient in the short wavelength UV.
FIG. X1.4 Spectral Power Distributions of UVA-351 Lamp and
Sunlight Through Window Glass
FIG. X1.5 Spectral Power Distributions of Unfiltered UVB-313
Lamp, UVB-313 Through Window Glass, and Sunlight Through
Window Glass
FIG. X1.6 Spectral Power Distributions of Unfiltered UVA-340
Lamp, UVA-340 Through Window Glass, and Sunlight Through
Window Glass
FIG. X1.7 Spectral Power Distributions of Unfiltered UVA-351
Lamp, UVA-351 Through Window Glass, and Sunlight Through
Window Glass
X2. EXPOSURE CONDITIONS
X2.1 Any exposure conditions may be used, as long as the
exact conditions are detailed in the report. Following are some
representative exposure conditions. These are not necessarily
preferred and no recommendation is implied. These conditions
are provided for reference only （See Table X2.1）.
NOTE X2.1—Cycle 1 is a commonly used exposure cycle for coatings
and plastics. Cycle 2 has been widely used for coatings. Cycles 3 and 4
have been used for exterior automotive materials. Cycle 5 has been used
for roofing materials. Cycle 6 has been used for high irradiance exposures
of coatings and plastics. Cycle 7 has been used for thermal shock and for
erosion testing of coatings for wood.
NOTE X2.2—When selecting programs of UV exposure followed by
condensation, allow at least 2 h per interval to assure attainment of
equilibrium.
NOTE X2.3—Surface temperature of specimens is an essential test
quantity. Generally, degradation processes accelerate with increasing
temperature. The specimen temperature permissible for the accelerated
test depends on the material to be tested and on the aging criterion under
consideration.
NOTE X2.4—Irradiance data shown is typical. Frequently, the irradiance
is not controlled in this type of exposure device.
NOTE X2.5—The light output of fluorescent lamps is affected by the
temperature of the air which surrounds the lamps. Consequently, in testers
without feed-back-loop control of irradiance, the lamp output will
decrease with increasing chamber temperature.
NOTE X2.6—Laboratory ambient temperature may have an effect on the
light output of devices without feed-back-loop control of irradiance. Some
fluorescent UV devices use laboratory ambient air to cool the lamps and
thereby compensate for the drop in light output at higher exposure
temperatures （see Note X2.5）.
X2.2 For the most consistent results, it is recommended that
apparatus without feed-back-loop control of irradiance be
operated in an environment in which the ambient temperature
is maintained between 18 and 27°C. Apparatus operated in
ambient temperatures above or below this range may produce
irradiances different from devices operated in the recommended
manner.
NOTE X2.7—Fluorescent UV lamps emit relatively little infrared radiation
when compared to xenon arc and carbon arc sources. In fluorescent
UV apparatus, the primary heating of the specimen surface is by
convection from heated air passing across the panel. Therefore, there is a
minimal difference between the temperature of an insulated or uninsulated
black or white panel thermometer, specimen surface, air in the test
chamber, or different colored samples （3）.
X2.3 For conversion of test cycles described in Practice
G 53 to test cycles described in Practice G 154 see Table X2.2.
TABLE X2.1 Common Exposure Conditions
Cycle Lamp Typical Irradiance Approximate Wavelength Exposure Cycle
1 UVA-340 0.77 W/m2/nm 340 nm 8 h UV at 60 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
2 UVB-313 0.63 W/m2/nm 310 nm 4 h UV at 60 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
3 UVB-313 0.44 W/m2/nm 310 nm 8 h UV at 70 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
4 UVA-340 1.35 W/m2/nm 340 nm 8 h UV at 70 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
5 UVB-313 0.55 W/m2/nm 310 nm 20 h UV at 80 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
6 UVA-340 1.35 W/m2/nm 340 nm 8 h UV at 60 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature.
7 UVA-340 1.35 W/m2/nm 340 nm 8 h UV at 60 （6 3） °C Black Panel Temperature;
0.25 h water spray （no light）, temperature not controlled;
3.75 h condensation at 50 （6 3） °C Black Panel Temperature
8 UVB-313 28 W/m2 270 to 700 nm 8 h UV at 70 （6 3） °C Black Panel Temperature;
4 h Condensation at 50 （6 3） °C Black Panel Temperature
REFERENCES
（1） Mullen, P. A., Kinmonth, R. A., and Searle, N. D., “Spectral Energy
Distributions and Aging Characteristics of Fluorescent Sun Lamps and
Black Lights,” Journal of Testing and Evaluation, Vol 3（1）, 15–20,
1975.
（2） Fedor, G. R., and Brennan, P. J., “Irradiance Control in Fluorescent UV
Exposure Testors,” Accelerated and Outdoor Durability Testing of
Organic Materials, ASTM STP 1202, American Society for Testing and
Materials, 1993.
（3） Ketola, W., Robbins, J. S., “UV Transmission of Single Strength
Window Glass,” Accelerated and Outdoor Durability Testing of
Organic Materials. ASTM STP 1202. Warren D. Ketola and Douglas
Grossman, Editors, American Society for Testing and Materials, 1993.
（4） Fischer, R. M., “Results of Round-Robin Studies of Light- and
Water-Exposure Standard Practices,” Accelerated and Outdoor Durability
Testing of Organic Materials, ASTM STP 1202. Warren K.
Ketola and Douglas Grossman, Editors, American Society for Testing
and Materials, 1993.
（5） Fischer, R. M., and Ketola, W. D., “Surface Temperatures of Materials
in Exterior Exposures and Artificial Accelerated Tests,” Accelerated
and Outdoor Durability Testing of Organic Materials, ASTM STP
1202. Warren K. Ketola and Douglas Grossman, Editors, American
Society for Testing and Materials, 1993.
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TABLE X2.2 Conversion of Test Cycles Described in Practice
G 53 to Test Cycles Described in Practice G 154
Practice G 53 Test Cycle
Description
Corresponding Test Cycle in
Practice G 154
Practice G 53 describes one
default cycle of 4 hours UV at
60°C, 4 hours condensation at
50°C. The default lamp for this
and other cycles is the UVB
lamps with peak emission at 313
nm, but fluorescent UVA lamps
with peak emission at 343 nm or
351 nm may also be used.
Cycle 2 of Table X2.1 describes
the Practice G 53 default cycle
using UVB-313 lamps.
Practice G 53 indicated that a
cycle of 8 hours UV and 4 hours
condensation is widely used.
Suggested temperatures during
UV exposure were 50°C, 60°C,
70°C
Table X2.1 describes 6 specific
exposure cycles that use 8 hours
UV followed by 4 hours
condensation. These cycles use
either UVA-340 or UVB-313
lamps.
G 154