ASTM D4303-10(2016)
(Test Method)Standard Test Methods for Lightfastness of Colorants Used in Artists' Materials
Standard Test Methods for Lightfastness of Colorants Used in Artists' Materials
SIGNIFICANCE AND USE
5.1 The retention of chromatic properties by a colorant over a long period of years is essential in a work of art. Accelerated exposure simulates color changes that may reasonably be expected. The producer and the user of artists' materials, therefore, can be apprised of suitable colorants.
5.2 Variations in results may be expected between the test methods. Also, some variation may be expected when the same test is repeated. Variations in Methods A and B are due to differences in outdoor conditions that are not accounted for in testing to equivalent radiant exposures. Information on sources of variability and strategies for addressing variability in laboratory accelerated exposure tests is found in Guide G141.
5.3 This standard does not cover factors other than lightfastness that can affect the permanence of art materials.
SCOPE
1.1 Four test methods to accelerate the effects of long term indoor illumination on artists’ materials are described below. One of the natural daylight methods and one of the xenon-arc methods are used to categorize the lightfastness of colorants.
1.1.1 Test Method A—Exposure in southern Florida to natural daylight filtered through window glass.
1.1.2 Test Method B—Exposure in Arizona to natural daylight filtered through window glass.
1.1.3 Test Method C—Exposure in a non-humidity controlled xenon-arc device simulating daylight filtered through window glass.
1.1.4 Test Method D—Exposure in a humidity controlled xenon-arc device simulating daylight filtered through window glass.
1.2 These test methods are used to approximate the color change that can be expected over time in colorants used in artists' materials exposed indoors to daylight through window glass.
Note 1: The color changes that result from accelerated exposure may not duplicate the results of normal indoor exposure in a home, art gallery, or museum. The relative resistance to change, however, can be established so colored materials can be assigned to categories of relative lightfastness.
Note 2: Users who wish to test colored materials under fluorescent illumination should consult Practice D4674.
1.3 Lightfastness categories are established to which colorants are assigned based on the color difference between specimens before and after exposure.
1.4 Color difference units are calculated by the CIE 1976 L*a*b* color difference equation.
1.5 These test methods apply to colored artists’ materials.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 This standard does not purport to address 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.
General Information
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D4303 − 10 (Reapproved 2016)
Standard Test Methods for
Lightfastness of Colorants Used in Artists’ Materials
This standard is issued under the fixed designation D4303; the number immediately 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope of the user of this standard to establish appropriate safety and
health practices and determine the applicability of regulatory
1.1 Four test methods to accelerate the effects of long term
limitations prior to use.
indoor illumination on artists’ materials are described below.
One of the natural daylight methods and one of the xenon-arc
2. Referenced Documents
methods are used to categorize the lightfastness of colorants.
2.1 ASTM Standards:
1.1.1 Test Method A—Exposure in southern Florida to
D2244 Practice for Calculation of Color Tolerances and
natural daylight filtered through window glass.
Color Differences from Instrumentally Measured Color
1.1.2 Test Method B—Exposure in Arizona to natural day-
Coordinates
light filtered through window glass.
D4302 Specification for Artists’ Oil, Resin-Oil, and Alkyd
1.1.3 Test Method C—Exposure in a non-humidity con-
Paints
trolled xenon-arc device simulating daylight filtered through
D4674 PracticeforAcceleratedTestingforColorStabilityof
window glass.
Plastics Exposed to Indoor Office Environments
1.1.4 Test Method D—Exposure in a humidity controlled
D5067 Specification for Artists’ Watercolor Paints
xenon-arc device simulating daylight filtered through window
D5098 Specification for Artists’Acrylic Dispersion Paints
glass.
D5724 Specification for Gouache Paints
1.2 These test methods are used to approximate the color
D6901 Specification for Artists’ Colored Pencils
change that can be expected over time in colorants used in
E284 Terminology of Appearance
artists’ materials exposed indoors to daylight through window
E1347 Test Method for Color and Color-Difference Mea-
glass.
surement by Tristimulus Colorimetry
NOTE 1—The color changes that result from accelerated exposure may E1348 Test Method for Transmittance and Color by Spec-
not duplicate the results of normal indoor exposure in a home, art gallery,
trophotometry Using Hemispherical Geometry
or museum.The relative resistance to change, however, can be established
E1349 Test Method for Reflectance Factor and Color by
so colored materials can be assigned to categories of relative lightfastness.
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
NOTE 2—Users who wish to test colored materials under fluorescent
Geometry
illumination should consult Practice D4674.
G24 Practice for Conducting Exposures to Daylight Filtered
1.3 Lightfastness categories are established to which colo-
Through Glass
rants are assigned based on the color difference between
G113 Terminology Relating to Natural andArtificial Weath-
specimens before and after exposure.
ering Tests of Nonmetallic Materials
1.4 Color difference units are calculated by the CIE 1976
G141 Guide for Addressing Variability in Exposure Testing
L*a*b* color difference equation.
of Nonmetallic Materials
G151 Practice for Exposing Nonmetallic Materials inAccel-
1.5 These test methods apply to colored artists’ materials.
erated Test Devices that Use Laboratory Light Sources
1.6 The values stated in SI units are to be regarded as the
G155 Practice for Operating XenonArc LightApparatus for
standard. The values given in parentheses are for information
Exposure of Non-Metallic Materials
only.
1.7 This standard does not purport to address the safety
3. Terminology
concerns, if any, associated with its use. It is the responsibility
3.1 Definitions—Appearance terms used in these test meth-
ods are defined inTerminology E284.Terms relating to natural
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.57 on Artist Paints and Related Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2016. Published July 2016. Originally approved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 1983. Last previous edition approved in 2010 as D4303 – 10. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D4303-10R16. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4303 − 10 (2016)
and artificial lightfastness tests are defined in Terminology 7. Procedure
G113.
7.1 Prepare seven specimens of the art materials to be
3.1.1 glass, n—as used in these test methods, glass refers to
tested, following the directions given in the appropriate speci-
single-strength window glass.
fication. If there is no specification for the art material, seven
specimens must be prepared that are as similar, uniform, and
4. Summary of Test Method
opaque as possible.
7.1.1 Two specimens of each color shall be exposed in each
4.1 Color measurements are made on duplicate specimens
of two test methods, either A or B and either C or D. One
that have been prepared as directed in the specification for that
specimen of each color shall be retained for a visual compari-
material. Examples of specifications are: D4302, D5067,
son with the test specimens following exposure, and two
D5098, D5724, and D6901. Each contains colorants in a
specimens shall be retained for use in a third exposure if
different vehicle. The measurements are recorded for compari-
needed.
son with readings made after the specimens have been ex-
posed. 7.1.2 The retained, unexposed specimens are stored in the
dark unless the formulation contains oil. Store specimens that
4.2 Lightfastness is determined by exposing the specimens
contain oil in a light level of 500 to 700 lux (50 to 75 fc) to
to daylight filtered through glass outdoors either in southern
prevent yellowing. If specimens must be stored for as long as
Florida or inArizona and also to xenon arc radiation through a
100 days, store all specimens in the dark, but remove those
window glass filter.
containing oil and place in the light level specified above to
4.3 The colorants are classified by the amount of color
prevent yellowing for at least 7 days before measurement or
change calculated as ∆E* units in accordance with Practice
visual evaluation.
D2244.
7.1.3 Cut the specimen to a size that will fit the holder to be
used for exposure and the port of the color measuring instru-
4.4 Variations in test results can be due to differences in
ment.
specimen preparation, surface irregularities, color measure-
7.1.4 Determine if test specimens are opaque. Colors mixed
ments and conditions of exposure. Allowance for these varia-
with white, as described in the specifications for artists’paints,
tions is made by assigning a wide range of color change n each
are opaque. Other materials must be applied over both a black
of the five lightfastness categories. Colorants are placed in one
substrate and a white substrate to determine opacity. Any
of these categories based on the mean of the ∆E* values
measured color difference between the color over black and
obtained from two or more types of exposure. Only colorants
over white indicates a lack of opacity.
that place in the first two categories conform to the require-
7.1.4.1 A measurement representative of the whole speci-
ments of this standard.
men must be obtained if the specimen is not opaque. To get a
representative measure of the color, both before and after
5. Significance and Use
exposure.either(1)usealargemeasuringportof25mm(1in.)
5.1 The retention of chromatic properties by a colorant over
diameter,or(2)usingasmallport,obtainthemeanofanumber
a long period of years is essential in a work of art.Accelerated
of measurements of various areas of the specimens, and
exposure simulates color changes that may reasonably be
compare it with the mean of a second set of measurements of
expected. The producer and the user of artists’ materials,
different areas. If the means agree, use that value as the
therefore, can be apprised of suitable colorants.
representative color. Otherwise, repeat the procedure until
agreement is obtained.
5.2 Variations in results may be expected between the test
methods.Also, some variation may be expected when the same
7.2 Immediately before exposure, measure all test speci-
test is repeated. Variations in Methods A and B are due to
mens using a spectrophotometer or spectrocolorimeter (see
differences in outdoor conditions that are not accounted for in
Test Method E1348 or E1349) or colorimeter (seeTest Method
testing to equivalent radiant exposures. Information on sources
E1347) using Illuminant D65 and the 1964 10° Observer and
of variability and strategies for addressing variability in labo-
excluding specular reflection from the measurement. Record
ratory accelerated exposure tests is found in Guide G141.
the CIELAB measurement data.
7.2.1 Measure specimen panels with any brush marks in the
5.3 This standard does not cover factors other than light-
same direction and measure the same area of the panel before
fastness that can affect the permanence of art materials.
andaftereachexposureinterval.Ifthedesignoftheinstrument
allows, three readings at different locations on the panel should
6. Apparatus
be made and the mean calculated. If feasible, mark on the back
6.1 Outdoor Exposure Facilities as described in Practice
of the specimen the spot(s) measured, and remeasure these
G24, using an exposure angle of 45°, facing the equator.
same spots following exposure.
6.2 Xenon-Arc Lightfastness Apparatus as described in
7.3 Expose duplicate specimens in each of two test
Practice G155.
methods, outdoor Test Method A or B and xenon arc Test
Method C or D, as described below:
6.3 Spectrophotometer, abridged spectrophotometer or colo-
rimeter capable of excluding specular reflectance in its mea- 7.3.1 Test Method A—Exposure in Southern Florida Below
surement. 27° Latitude to Natural Daylight Filtered Through Window
D4303 − 10 (2016)
maximum deviation allowable from the set point of the sensor at the
Glass—Test Method A can be used for under glass outdoor
control point during equilibrium conditions.
exposure if the material is an oil paint or acrylic dispersion
NOTE 4—To track the rate of color change in the xenon arc exposure,
paint on an aluminum substrate.
the total exposure time can be divided into three or more phases and the
7.3.1.1 Mountduplicatespecimensofeachcoloronanopen
device programmed to stop at the end of each phase so the specimens can
sided rack under glass and expose in southern Florida at a 45
be measured and recorded. Then specimens are returned to the test
degree angle to the horizontal facing south during October chamber and exposure continues until the total required amount of
irradiation is reached.
through May to a total global solar (290 to 2500 nm) radiation
dose of 1260 MJ/m incident on the glass, in accordance with
7.3.4 Test Method D—Exposure Simulating Daylight Fil-
Practice G24.
tered Through Window Glass in a Humidity Controlled Xenon-
7.3.2 Test Method B—Exposure in Arizona to Natural Day-
Arc Device—This environment will typically have higher
light Filtered Through Window Glass—Use Test Method B if
relative humidity than Test Method C:
the test specimens are prepared on a paper substrate or the
7.3.4.1 Follow 7.3.3.1.
vehicle is affected by the combination of high moisture content
7.3.4.2 Mount specimens in unbacked holders and follow
and temperature fluctuations that are characteristic of south
step (a)in 7.3.3.1. It is recommended that all unused spaces in
Florida. Examples are watercolor and gouache paints, colored
the specimen exposure area be filled with blank metal panels
pencils, colored water-thinned inks, and pastels.
that are not highly reflective.
7.3.2.1 Mountduplicatespecimensinanenclosedblackbox
7.3.4.3 Follow 7.3.3.2.
with a small fan to circulate the air and expose inArizona at a
7.3.4.4 Follow 7.3.3.3.
45 degree angle to the horizontal facing south during October
7.3.4.5 Set the relative humidity at the control point in the
through May to a total global solar (290 to 2500 nm) radiation
2 test chamber to 55 6 5 % RH.
dose of 1260 MJ/m incident on the glass, in accordance with
7.3.4.6 In machines that allow control of chamber air
Practice G24.
temperature, it shall be set at 43 6 2°C.
7.3.3 Test Method C—Exposure Simulating Daylight Fil-
tered Through Window Glass in a Xenon Arc Device That Does
NOTE 5—Duplicate specimens should not be placed near one another
Not Control the Relative Humidity—This method will gener-
during the exposures.
NOTE 6—It has been found that Alizarin Crimson and other colorants
ally have a low relative humidity.
are affected differently when exposed to a light/dark cycle rather than to
7.3.3.1 Use a xenon-arc device that conforms to the require-
continuouslight.Darkperiodsarecharacteristicofexposuretodaylightas
ments defined in Practices G151 and G155. Unless otherwise
well as to indoor lighting. Therefore, when mutually agreed upon, the
specified, the spectral power distribution of the xenon-arc shall
followingalternativelightanddarkcyclemaybeemployedasanalternate
conform to the requirements in Practice G155 for xenon arc
constantlight:3.8hlightfollowedby1hdark.Duringthelightperiod,the
conditions of irradiance, temperature and humidity are as given in 7.3.3 or
radiation through a window glass filter.
7.3.4. During the dark period, the uninsulated black panel temperature
(a) Place specimens in the test device in positions that
shallbesetat35 62°Catthecontrolpoint.Inmachinesthatallowcontrol
conform with specifications in Practice G151 or use the
of air chamber temperature, it shall also be set at 35 6 2°C at the control
procedures described in this practice that either ensure equal
point. In machines that allow control of relative humidity, it shall be set at
radiant exposure on all specimens or compensate for irradiance 55 6 5° RH at the control point, during both light and dark periods. Any
variance from the specified test cycle must be detailed in the Report
differences within the exposure chamber. To assure equal
section.
radiant exposure it may be necessary to reposition specimens
during exposure.
7.4 Following exposure, if the surface of an exposed test
7.3.3.2 Unless agreed otherwise, set the irradiance at the specimen appears excessively streaked or spotty, showing
areasofwhitesubstrate,assign
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4303 − 10 D4303 − 10 (Reapproved 2016)
Standard Test Methods for
Lightfastness of Colorants Used in Artists’ Materials
This standard is issued under the fixed designation D4303; the number immediately 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Four test methods to accelerate the effects of long term indoor illumination on artists’artists’ materials are described below.
One of the natural daylight methods and one of the xenon-arc methods are used to categorize the lightfastness of colorants.
1.1.1 Test Method A—Exposure in southern Florida to natural daylight filtered through window glass.
1.1.2 Test Method B—Exposure in Arizona to natural daylight filtered through window glass.
1.1.3 Test Method C—Exposure in a non-humidity controlled xenon-arc device simulating daylight filtered through window
glass.
1.1.4 Test Method D—Exposure in a humidity controlled xenon-arc device simulating daylight filtered through window glass.
1.2 These test methods are used to approximate the color change that can be expected over time in colorants used in artists’
materials exposed indoors to daylight through window glass.
NOTE 1—The color changes that result from accelerated exposure may not duplicate the results of normal indoor exposure in a home, art gallery, or
museum. The relative resistance to change, however, can be established so colored materials can be assigned to categories of relative lightfastness.
NOTE 2—Users who wish to test colored materials under fluorescent illumination should consult Practice D4674.
1.3 Lightfastness categories are established to which colorants are assigned based on the color difference between specimens
before and after exposure.
1.4 Color difference units are calculated by the CIE 1976 L*a*b* color difference equation.
1.5 These test methods apply to colored artists’artists’ materials.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 This standard does not purport to address 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.
2. Referenced Documents
2.1 ASTM Standards:
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
D4302 Specification for Artists’ Oil, Resin-Oil, and Alkyd Paints
D4674 Practice for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Office Environments
D5067 Specification for Artists’ Watercolor Paints
D5098 Specification for Artists’ Acrylic Dispersion Paints
D5724 Specification for Gouache Paints
D6901 Specification for Artists’ Colored Pencils
E284 Terminology of Appearance
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
E1348 Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry
E1349 Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45°:0° or 0°:45°) Geometry
G24 Practice for Conducting Exposures to Daylight Filtered Through Glass
These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility of
Subcommittee D01.57 on Artist Paints and Related Materials.
Current edition approved June 1, 2010July 1, 2016. Published June 2010July 2016. Originally approved in 1983. Last previous edition approved in 20062010 as
D4303 – 06.D4303 – 10. DOI: 10.1520/D4303-10.10.1520/D4303-10R16.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4303 − 10 (2016)
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G141 Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials
3. Terminology
3.1 Definitions—Appearance terms used in these test methods are defined in Terminology E284. Terms relating to natural and
artificial lightfastness tests are defined in Terminology G113.
3.1.1 glass, n—as used in these test methods, glass refers to single-strength window glass.
4. Summary of Test Method
4.1 Color measurements are made on duplicate specimens that have been prepared as directed in the specification for that
material. Examples of specifications are: D4302, D5067, D5098, D5724, and D6901. Each contains colorants in a different vehicle.
The measurements are recorded for comparison with readings made after the specimens have been exposed.
4.2 Lightfastness is determined by exposing the specimens to daylight filtered through glass outdoors either in southern Florida
or in Arizona and also to xenon arc radiation through a window glass filter.
4.3 The colorants are classified by the amount of color change calculated as ΔE* units in accordance with Practice D2244.
4.4 Variations in test results can be due to differences in specimen preparation, surface irregularities, color measurements and
conditions of exposure. Allowance for these variations is made by assigning a wide range of color change n each of the five
lightfastness categories. Colorants are placed in one of these categories based on the mean of the ΔE* values obtained from two
or more types of exposure. Only colorants that place in the first two categories conform to the requirements of this standard.
5. Significance and Use
5.1 The retention of chromatic properties by a colorant over a long period of years is essential in a work of art. Accelerated
exposure simulates color changes that may reasonably be expected. The producer and the user of artists’ materials, therefore, can
be apprised of suitable colorants.
5.2 Variations in results may be expected between the test methods. Also, some variation may be expected when the same test
is repeated. Variations in Methods A and B are due to differences in outdoor conditions that are not accounted for in testing to
equivalent radiant exposures. Information on sources of variability and strategies for addressing variability in laboratory
accelerated exposure tests is found in Guide G141.
5.3 This standard does not cover factors other than lightfastness that can affect the permanence of art materials.
6. Apparatus
6.1 Outdoor Exposure Facilities as described in Practice G24, using an exposure angle of 45°, facing the equator.
6.2 Xenon-Arc Lightfastness Apparatus as described in Practice G155.
6.3 Spectrophotometer, abridged spectrophotometer or colorimeter capable of excluding specular reflectance in its measure-
ment.
7. Procedure
7.1 Prepare seven specimens of the art materials to be tested, following the directions given in the appropriate specification. If
there is no specification for the art material, seven specimens must be prepared that are as similar, uniform, and opaque as possible.
7.1.1 Two specimens of each color shall be exposed in each of two test methods, either A or B and either C or D. One specimen
of each color shall be retained for a visual comparison with the test specimens following exposure, and two specimens shall be
retained for use in a third exposure if needed.
7.1.2 The retained, unexposed specimens are stored in the dark unless the formulation contains oil. Store specimens that contain
oil in a light level of 500 to 700 lux (50 to 75 fc) to prevent yellowing. If specimens must be stored for as long as 100 days, store
all specimens in the dark, but remove those containing oil and place in the light level specified above to prevent yellowing for at
least 7 days before measurement or visual evaluation.
7.1.3 Cut the specimen to a size that will fit the holder to be used for exposure and the port of the color measuring instrument.
7.1.4 Determine if test specimens are opaque. Colors mixed with white, as described in the specifications for artists’artists’
paints, are opaque. Other materials must be applied over both a black substrate and a white substrate to determine opacity. Any
measured color difference between the color over black and over white indicates a lack of opacity.
7.1.4.1 A measurement representative of the whole specimen must be obtained if the specimen is not opaque. To get a
representative measure of the color, both before and after exposure. either (1) use a large measuring port of 25 mm (1 in.) diameter,
or (2) using a small port, obtain the mean of a number of measurements of various areas of the specimens, and compare it with
D4303 − 10 (2016)
the mean of a second set of measurements of different areas. If the means agree, use that value as the representative color.
Otherwise, repeat the procedure until agreement is obtained.
7.2 Immediately before exposure, measure all test specimens using a spectrophotometer or spectrocolorimeter (see Test Method
E1348 or E1349) or colorimeter (see Test Method E1347) using Illuminant D65 and the 1964 10° Observer and excluding specular
reflection from the measurement. Record the CIELAB measurement data.
7.2.1 Measure specimen panels with any brush marks in the same direction and measure the same area of the panel before and
after each exposure interval. If the design of the instrument allows, three readings at different locations on the panel should be made
and the mean calculated. If feasible, mark on the back of the specimen the spot(s) measured, and remeasure these same spots
following exposure.
7.3 Expose duplicate specimens in each of two test methods, outdoor Test Method A or B and xenon arc Test Method C or D,
as described below:
7.3.1 Test Method A—Exposure in Southern Florida Below 27° Latitude to Natural Daylight Filtered Through Window
Glass—Test Method A can be used for under glass outdoor exposure if the material is an oil paint or acrylic dispersion paint on
an aluminum substrate.
7.3.1.1 Mount duplicate specimens of each color on an open sided rack under glass and expose in southern Florida at a 45 degree
angle to the horizontal facing south during October through May to a total global solar (290 to 2500 nm) radiation dose of 1260
MJ/m incident on the glass, in accordance with Practice G24.
7.3.2 Test Method B—Exposure in Arizona to Natural Daylight Filtered Through Window Glass—Use Test Method B if the test
specimens are prepared on a paper substrate or the vehicle is affected by the combination of high moisture content and temperature
fluctuations that are characteristic of south Florida. Examples are watercolor and gouache paints, colored pencils, colored
water-thinned inks, and pastels.
7.3.2.1 Mount duplicate specimens in an enclosed black box with a small fan to circulate the air and expose in Arizona at a 45
degree angle to the horizontal facing south during October through May to a total global solar (290 to 2500 nm) radiation dose
of 1260 MJ/m incident on the glass, in accordance with Practice G24.
7.3.3 Test Method C—Exposure Simulating Daylight Filtered Through Window Glass in a Xenon Arc Device That Does Not
Control the Relative Humidity—This method will generally have a low relative humidity.
7.3.3.1 Use a xenon-arc device that conforms to the requirements defined in Practices G151 and G155. Unless otherwise
specified, the spectral power distribution of the xenon-arc shall conform to the requirements in Practice G155 for xenon arc
radiation through a window glass filter.
(a) Place specimens in the test device in positions that conform with specifications in Practice G151 or use the procedures
described in this practice that either ensure equal radiant exposure on all specimens or compensate for irradiance differences within
the exposure chamber. To assure equal radiant exposure it may be necessary to reposition specimens during exposure.
7.3.3.2 Unless agreed otherwise, set the irradiance at the control point to 0.35 6 0.02 at 340 nm and expose specimens to 100 %
2 2
light to reach a total radiant exposure of 510 kJ/(m ·nm) at 340 nm, the equivalent to 1260 MJ/m of total solar radiation. For a
xenon-arc device that controls exposure at 300 to 800 nm, set the irradiance at the control point to 500 W/m and expose to 100 %
light to reach a total radiant exposure of 739 MJ/m at 300 to 800 nm. For xenon arc devices that control exposures in a different
spectral region, consult the manufacturer of the device for the irradiance and radiant exposure required to produce equivalent test
results.
7.3.3.3 The uninsulated black panel temperature shall be 63 6 2°C. For the equivalent insulated black panel temperature,
consult the manufacturer of the device.
NOTE 3—The set points specified for irradiance, temperature and humidity are the target conditions for the sensor programmed by the user at the control
point. Therefore, when a standard calls for a particular set point, the user programs that exact number. The operational fluctuation specified with the set
point does not imply that the user is allowed to program a set point higher or lower than the exact set point specified. Operational fluctuation is determined
by the machine variable and is the maximum deviation allowable from the set point of the sensor at the control point during equilibrium conditions.
NOTE 4—To track the rate of color change in the xenon arc exposure, the total exposure time can be divided into three or more phases and the device
programmed to stop at the end of each phase so the specimens can be measured and recorded. Then specimens are returned to the test chamber and
exposure continues until the total required amount of irradiation is reached.
7.3.4 Test Method D—Exposure Simulating Daylight Filtered Through Window Glass in a Humidity Controlled Xenon-Arc
Device—This environment will typically have higher relat
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.