ASTM D3361/D3361M-13(2018)

Standard Practice for Unfiltered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings

SIGNIFICANCE AND USE
4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat, and water can be very significant for many applications. This practice is intended to induce property changes associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and saltwater exposure.  
4.2 Cautions—Variation in results may be expected when different operating conditions are used. Therefore, no reference to the use of this practice shall be made unless accompanied by a report prepared according to Section 10 that describes the specific operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained according to this practice.
Note 1: Additional information on sources of variability and on strategies for addressing variability in the design, execution, and data analysis of laboratory accelerated exposure tests is found in Guide G141.  
4.2.1 The spectral power distribution of light from an unfiltered open-flame carbon arc is significantly different from that produced in light and water exposure devices using other carbon-arc configurations or other light sources. The type and rate of degradation and the performance rankings produced by exposures to unfiltered open-flame carbon-arcs can be much different from that produced by exposures to other types of laboratory light sources. Typically, exposures conducted according to this practice will produce degradation faster than similar exposures conducted in accordance with Practice D822/D822M or D5031/D5031M and may cause different types of degradation.  
4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon-arc and exposure conditions.  
4.3 Reproducibility of test resu...
SCOPE
1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in unfiltered open-flame carbon-arc devices conducted according to Practice G151 and G152. This practice also covers the preparation of test specimens, the test conditions suited for coatings, and the evaluation of test results.  
1.2 This practice covers unfiltered open-flame carbon-arc exposures of paints and related coatings, and covers the exposure cycle that has been commonly referred to as the “dew cycle.” Practice D822/D822M describes filtered open-flame carbon-arc devices, and Practice D5031/D5031M describes enclosed carbon-arc exposures. The radiation from an unfiltered open-flame carbon arc produces shorter wavelengths and higher levels of short wavelength radiation than either filtered open-flame or enclosed carbon arcs.  
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 31-Aug-2018
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.27 - Accelerated Testing

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: D3361/D3361M −13 (Reapproved 2018)
Standard Practice for
Unfiltered Open-Flame Carbon-Arc Exposures of Paint and
Related Coatings
This standard is issued under the fixed designation D3361/D3361M; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers the selection of test conditions for
D358 Specification for Wood to Be Used as Panels in
acceleratedexposuretestingofcoatingsandrelatedproductsin
Weathering Tests of Coatings (Withdrawn 2014)
unfiltered open-flame carbon-arc devices conducted according
D523 Test Method for Specular Gloss
to Practice G151 and G152. This practice also covers the
D609 Practice for Preparation of Cold-Rolled Steel Panels
preparation of test specimens, the test conditions suited for
for Testing Paint, Varnish, Conversion Coatings, and
coatings, and the evaluation of test results.
Related Coating Products
1.2 This practice covers unfiltered open-flame carbon-arc
D610 Practice for Evaluating Degree of Rusting on Painted
exposures of paints and related coatings, and covers the
Steel Surfaces
exposure cycle that has been commonly referred to as the “dew
D659 Method for Evaluating Degree of Chalking of Exterior
cycle.” Practice D822/D822M describes filtered open-flame
Paints (Withdrawn 1990)
carbon-arc devices, and Practice D5031/D5031M describes
D660 Test Method for Evaluating Degree of Checking of
enclosed carbon-arc exposures. The radiation from an unfil-
Exterior Paints
tered open-flame carbon arc produces shorter wavelengths and
D662 Test Method for Evaluating Degree of Erosion of
higher levels of short wavelength radiation than either filtered
Exterior Paints
open-flame or enclosed carbon arcs.
D714 Test Method for Evaluating Degree of Blistering of
Paints
1.3 The values stated in either SI units or inch-pound units
D772 Test Method for Evaluating Degree of Flaking (Scal-
are to be regarded separately as standard. The values stated in
ing) of Exterior Paints
each system may not be exact equivalents; therefore, each
D822/D822M Practice for Filtered Open-Flame Carbon-Arc
system shall be used independently of the other. Combining
Exposures of Paint and Related Coatings
values from the two systems may result in non-conformance
D823 Practices for Producing Films of Uniform Thickness
with the standard.
of Paint, Coatings and Related Products on Test Panels
D1005 Test Method for Measurement of Dry-Film Thick-
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the ness of Organic Coatings Using Micrometers
D1186 Test Methods for Nondestructive Measurement of
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- Dry Film Thickness of Nonmagnetic Coatings Applied to
a Ferrous Base (Withdrawn 2006)
mine the applicability of regulatory limitations prior to use.
D1400 TestMethodforNondestructiveMeasurementofDry
1.5 This international standard was developed in accor-
Film Thickness of Nonconductive Coatings Applied to a
dance with internationally recognized principles on standard-
Nonferrous Metal Base (Withdrawn 2006)
ization established in the Decision on Principles for the
D1729 Practice for Visual Appraisal of Colors and Color
Development of International Standards, Guides and Recom-
Differences of Diffusely-Illuminated Opaque Materials
mendations issued by the World Trade Organization Technical
D1730 Practices for Preparation of Aluminum and
Barriers to Trade (TBT) Committee.
Aluminum-Alloy Surfaces for Painting
1 2
This practice is under the jurisdiction of ASTM Committee D01 on Paint and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Related Coatings, Materials, and Applications and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee D01.27 on Accelerated Testing. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2018. Published September 2018. Originally the ASTM website.
approved in 1974. Last previous edition approved in 2013 as D3361/D3361M – 13. The last approved version of this historical standard is referenced on
DOI: 10.1520/D3361_D3361M-13R18. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3361/D3361M − 13 (2018)
D2244 Practice for Calculation of Color Tolerances and rate of degradation and the performance rankings produced by
Color Differences from Instrumentally Measured Color exposures to unfiltered open-flame carbon-arcs can be much
Coordinates different from that produced by exposures to other types of
D2616 Test Method for Evaluation of Visual Color Differ- laboratory light sources. Typically, exposures conducted ac-
ence With a Gray Scale cording to this practice will produce degradation faster than
D3980 Practice for Interlaboratory Testing of Paint and similarexposuresconductedinaccordancewithPracticeD822/
Related Materials (Withdrawn 1998) D822M or D5031/D5031M and may cause different types of
D4214 Test Methods for Evaluating the Degree of Chalking degradation.
of Exterior Paint Films 4.2.2 Interlaboratory comparisons are valid only when all
D5031/D5031M Practice for Enclosed Carbon-Arc Expo- laboratories use the same type of carbon-arc and exposure
sure Tests of Paint and Related Coatings conditions.
D5870 Practice for Calculating Property Retention Index of
4.3 Reproducibility of test results between laboratories has
Plastics
been shown to be good when the stability of materials is
E691 Practice for Conducting an Interlaboratory Study to
evaluated in terms of performance ranking compared to other
Determine the Precision of a Test Method 4,5
materials or to a control. Therefore, exposure of a similar
E1347 Test Method for Color and Color-Difference Mea-
material of known performance (a control) at the same time as
surement by Tristimulus Colorimetry
the test materials is strongly recommended. It is recommended
G113 Terminology Relating to Natural andArtificial Weath-
that at least three replicates of each material be exposed to
ering Tests of Nonmetallic Materials
allow for statistical evaluation of results.
G141 Guide for Addressing Variability in Exposure Testing
4.4 Test results will depend upon the care that is taken to
of Nonmetallic Materials
operate the equipment in accordance with Practice G152.
G147 Practice for Conditioning and Handling of Nonmetal-
Significant factors include regulation of line voltage, freedom
lic Materials for Natural and Artificial Weathering Tests
from salt or other deposits from water, temperature and
G151 Practice for Exposing Nonmetallic Materials inAccel-
humidity control, and conditions of the electrodes.
erated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light
4.5 All references to exposures in accordance with this
Apparatus for Exposure of Nonmetallic Materials practice must include a complete description of the test cycle
G169 Guide for Application of Basic Statistical Methods to
used.
Weathering Tests
5. Apparatus
3. Terminology
5.1 Use filtered open-flame carbon-arc apparatus with auto-
3.1 The definitions given in Terminology G113 are appli-
matic humidity control that conforms to the requirements
cable to this practice.
defined in Practices G151 and G152.
5.2 Do not place any filters between the open flame carbon
4. Significance and Use
arc and the test specimens.
4.1 The ability of a paint or coating to resist deterioration of
its physical and optical properties caused by exposure to light,
6. Hazards
heat, and water can be very significant for many applications.
6.1 Warning—In addition to other precautions, never look
This practice is intended to induce property changes associated
directly at the carbon arc because UVradiation can damage the
with end-use conditions, including the effects of sunlight,
eye. Most carbon-arc machines are equipped with door safety
moisture, and heat. The exposure used in this practice is not
switches, but users of old equipment must be certain to turn off
intended to simulate the deterioration caused by localized
the power to the carbon arc before opening the test-chamber
weather phenomena such as atmospheric pollution, biological
door.
attack, and saltwater exposure.
6.2 This light source generates ozone and nitrous oxides.
4.2 Cautions—Variation in results may be expected when
Vent exhaust from the exposure device to the atmosphere.
different operating conditions are used.Therefore, no reference
to the use of this practice shall be made unless accompanied by 6.3 The burning carbon rods used in these devices become
a report prepared according to Section 10 that describes the very hot during use. Make sure to allow at least 15 min for the
specific operating conditions used. Refer to Practice G151 for arcs to cool after the device is turned off before attempting to
detailed information on the caveats applicable to use of results change the carbon rods.
obtained according to this practice.
6.4 Carbon residue and ash are known respiratory irritants.
Wearanappropriatehigh-efficiencydustrespirator,gloves,and
NOTE 1—Additional information on sources of variability and on
strategies for addressing variability in the design, execution, and data
analysis of laboratory accelerated exposure tests is found in Guide G141.
Fischer, R., “Results of Round Robin Studies of Light- and Water-Exposure
4.2.1 The spectral power distribution of light from an
Standard Practices,” Accelerated and Outdoor Durability Testing of Organic
unfiltered open-flame carbon arc is significantly different from
Materials, ASTM STP 1202, ASTM, 1993.
that produced in light and water exposure devices using other
Ketola, W., and Fischer, R., “Characterization and Use of Reference Materials
carbon-arc configurations or other light sources. The type and inAcceleratedDurabilityTests,”VAMASTechnicalReportNo.30,NIST,June1997.
D3361/D3361M − 13 (2018)
safety glasses when handling or changing carbon rods. Make 7.10 Specimens should not ordinarily be removed from the
sure to wash any carbon residue from hands or arms prior to exposure apparatus for more than 24 h, then returned for
eating or drinking. additional tests, since this does not produce the same results on
allmaterialsastestsrunwithoutthistypeofinterruption.When
specimensareremovedfromtheexposureapparatusfor24hor
7. Test Specimens
more, then returned for additional exposure, report the elapsed
7.1 Apply the coating to flat (plane) panels with the
time as noted under Section 10.
substrate, method of preparation, method of application, coat-
ing system, film thickness, and method of drying consistent
8. Procedure
with the anticipated end use, or as mutually agreed upon
between the producer and user. 8.1 Unless otherwise specified, operate the device using the
followingexposurecyclesothattheallowabledeviationsabout
7.2 Panel specifications and methods of preparation include
the set points given with each set point below are within the
but are not limited to Practices D609 or D1730, or Specifica-
specified limits specified in the corresponding entry. If the
tion D358. Select panel sizes suitable for use with the exposure
actual operating conditions do not agree with the machine
apparatus.
settings after the equipment has stabilized, discontinue the test
7.3 Coat test panels in accordance withTest Methods D823, and correct the cause of the disagreement before continuing.
then measure the film thickness in accordance with an appro-
NOTE 3—Each set point and the corresponding operational fluctuations
priate procedure selected fromTest MethodsD1005, D1186,or
given in this section represent an operational control point for equilibrium
D1400. Nondestructive methods are preferred because panels
conditions at a single location in the cabinet, which may not necessarily
so measured need not be repaired. represent the uniformity of those conditions throughout the cabinet.
ASTM Committee G03 is working to refine these operational fluctuations
7.4 Prior to exposing coated panels in the apparatus, condi-
and address the uniformity issue.
tion them at 23 6 2°C [73 6 3°F] and 50 6 5 % relative
NOTE 4—Set points and operational fluctuations are listed as set point
6 operational fluctuation in this standard. They are sometimes listed in
humidity for one of the following periods in accordance with
separate columns. The set point is the target condition for the sensor used
the type of coating:
at the operational control point as programmed by the user. Operational
Baked coatings 24 h
fluctuations are deviations from the indicated set point at the control point
Radiation-cured coatings 24 h
indicated by the readout of the calibrated control sensor during equilib-
All other coatings 7 days min
rium operation and do not include measurement uncertainty. At the
operational control point, the operational fluctuation can exceed no more
7.4.1 Other procedures for preparation of test specimens
than the listed value at equilibrium. Therefore, when a standard calls for
may be used if agreed upon by all interested parties.
a particular set point, the user programs that exact number. The opera-
tional fluctuations specified with the set point do not imply that the user
7.5 Mount specimens in holders so that only the minimum
is allowed to program a set point higher or lower than the exact set point
specimen area required for support by the holder is covered.
specified.
Do not use this covered area of the specimen as part of the test
8.1.1 Sixty min light only with black panel temperature
area.
controlled at 63 6 5°C [145 6 9°F] and relative humidity
7.6 Unless otherwise specified, expose at least three repli-
controlled at 50 6 10 %.
cate specimens of each test and control material.
NOTE 5—The black panel temperature is for equilibrium conditions.
7.7 Follow the procedures described in Practice G147 for
There will be a period immediately after the dark cycle where the black
identification and conditioning and handling of specimens of
panel temperature will be less than the control limits given.
test, control, and reference materials prior to, during, and after
8.1.2 Sixty min dark with water spray on the back of test
exposure.
specimens. During this dark cycle the chamber air temperature
7.8 Do not mask the face of a specimen f
...

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: D3361/D3361M − 13 D3361/D3361M − 13 (Reapproved 2018)
Standard Practice for
Unfiltered Open-Flame Carbon-Arc Exposures of Paint and
Related Coatings
This standard is issued under the fixed designation D3361/D3361M; 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*Scope
1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in
unfiltered open-flame carbon-arc devices conducted according to Practice G151 and G152. This practice also covers the
preparation of test specimens, the test conditions suited for coatings, and the evaluation of test results.
1.2 This practice covers unfiltered open-flame carbon-arc exposures of paints and related coatings, and covers the exposure
cycle that has been commonly referred to as the “dew cycle.” Practice D822/D822M describes filtered open-flame carbon-arc
devices, and Practice D5031/D5031M describes enclosed carbon-arc exposures. The radiation from an unfiltered open-flame
carbon arc produces shorter wavelengths and higher levels of short wavelength radiation than either filtered open-flame or enclosed
carbon arcs.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D358 Specification for Wood to Be Used as Panels in Weathering Tests of Coatings (Withdrawn 2014)
D523 Test Method for Specular Gloss
D609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating
Products
D610 Practice for Evaluating Degree of Rusting on Painted Steel Surfaces
D659 Method for Evaluating Degree of Chalking of Exterior Paints (Withdrawn 1990)
D660 Test Method for Evaluating Degree of Checking of Exterior Paints
D662 Test Method for Evaluating Degree of Erosion of Exterior Paints
D714 Test Method for Evaluating Degree of Blistering of Paints
D772 Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
D822/D822M Practice for Filtered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
D823 Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
D1005 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
This practice is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.27 on Accelerated Testing.
Current edition approved Oct. 1, 2013Sept. 1, 2018. Published October 2013September 2018. Originally approved in 1974. Last previous edition approved in 20062013
as D3361 – 01 (2006).D3361/D3361M – 13. DOI: 10.1520/D3361_D3361M-13.10.1520/D3361_D3361M-13R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3361/D3361M − 13 (2018)
D1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous
Base (Withdrawn 2006)
D1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive Coatings Applied to a
Nonferrous Metal Base (Withdrawn 2006)
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D1730 Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
D2616 Test Method for Evaluation of Visual Color Difference With a Gray Scale
D3980 Practice for Interlaboratory Testing of Paint and Related Materials (Withdrawn 1998)
D4214 Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
D5031/D5031M Practice for Enclosed Carbon-Arc Exposure Tests of Paint and Related Coatings
D5870 Practice for Calculating Property Retention Index of Plastics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G141 Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G169 Guide for Application of Basic Statistical Methods to Weathering Tests
3. Terminology
3.1 The definitions given in Terminology G113 are applicable to this practice.
4. Significance and Use
4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat,
and water can be very significant for many applications. This practice is intended to induce property changes associated with
end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to
simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and saltwater
exposure.
4.2 Cautions—Variation in results may be expected when different operating conditions are used. Therefore, no reference to the
use of this practice shall be made unless accompanied by a report prepared according to Section 10 that describes the specific
operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained
according to this practice.
NOTE 1—Additional information on sources of variability and on strategies for addressing variability in the design, execution, and data analysis of
laboratory accelerated exposure tests is found in Guide G141.
4.2.1 The spectral power distribution of light from an unfiltered open-flame carbon arc is significantly different from that
produced in light and water exposure devices using other carbon-arc configurations or other light sources. The type and rate of
degradation and the performance rankings produced by exposures to unfiltered open-flame carbon-arcs can be much different from
that produced by exposures to other types of laboratory light sources. Typically, exposures conducted according to this practice
will produce degradation faster than similar exposures conducted in accordance with Practice D822/D822M or D5031/D5031M
and may cause different types of degradation.
4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon-arc and exposure conditions.
4.3 Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated
4,5
in terms of performance ranking compared to other materials or to a control. Therefore, exposure of a similar material of known
performance (a control) at the same time as the test materials is strongly recommended. It is recommended that at least three
replicates of each material be exposed to allow for statistical evaluation of results.
4.4 Test results will depend upon the care that is taken to operate the equipment in accordance with Practice G152. Significant
factors include regulation of line voltage, freedom from salt or other deposits from water, temperature and humidity control, and
conditions of the electrodes.
4.5 All references to exposures in accordance with this practice must include a complete description of the test cycle used.
Fischer, R., “Results of Round Robin Studies of Light- and Water-Exposure Standard Practices,” Accelerated and Outdoor Durability Testing of Organic Materials, ASTM
STP 1202, ASTM, 1993.
Ketola, W., and Fischer, R., “Characterization and Use of Reference Materials in Accelerated Durability Tests,” VAMAS Technical Report No. 30, NIST, June 1997.
D3361/D3361M − 13 (2018)
5. Apparatus
5.1 Use filtered open-flame carbon-arc apparatus with automatic humidity control that conforms to the requirements defined in
Practices G151 and G152.
5.2 Do not place any filters between the open flame carbon arc and the test specimens.
6. Hazards
6.1 Warning—In addition to other precautions, never look directly at the carbon arc because UV radiation can damage the eye.
Most carbon-arc machines are equipped with door safety switches, but users of old equipment must be certain to turn off the power
to the carbon arc before opening the test-chamber door.
6.2 This light source generates ozone and nitrous oxides. Vent exhaust from the exposure device to the atmosphere.
6.3 The burning carbon rods used in these devices become very hot during use. Make sure to allow at least 15 min for the arcs
to cool after the device is turned off before attempting to change the carbon rods.
6.4 Carbon residue and ash are known respiratory irritants. Wear an appropriate high-efficiency dust respirator, gloves, and
safety glasses when handling or changing carbon rods. Make sure to wash any carbon residue from hands or arms prior to eating
or drinking.
7. Test Specimens
7.1 Apply the coating to flat (plane) panels with the substrate, method of preparation, method of application, coating system,
film thickness, and method of drying consistent with the anticipated end use, or as mutually agreed upon between the producer
and user.
7.2 Panel specifications and methods of preparation include but are not limited to Practices D609 or D1730, or Specification
D358. Select panel sizes suitable for use with the exposure apparatus.
7.3 Coat test panels in accordance with Test Methods D823, then measure the film thickness in accordance with an appropriate
procedure selected from Test Methods D1005, D1186, or D1400. Nondestructive methods are preferred because panels so
measured need not be repaired.
7.4 Prior to exposing coated panels in the apparatus, condition them at 23 6 2°C [73 6 3°F] and 50 6 5 % relative humidity
for one of the following periods in accordance with the type of coating:
Baked coatings 24 h
Radiation-cured coatings 24 h
All other coatings 7 days min
7.4.1 Other procedures for preparation of test specimens may be used if agreed upon by all interested parties.
7.5 Mount specimens in holders so that only the minimum specimen area required for support by the holder is covered. Do not
use this covered area of the specimen as part of the test area.
7.6 Unless otherwise specified, expose at least three replicate specimens of each test and control material.
7.7 Follow the procedures described in Practice G147 for identification and conditioning and handling of specimens of test,
control, and reference materials prior to, during, and after exposure.
7.8 Do not mask the face of a specimen for the purpose of showing on one panel the effects of various exposure times.
Misleading results may be obtained by this method, since the masked portion of the specimen is still exposed to temperature and
humidity cycles that in many cases will affect results.
7.9 Retain a supply of unexposed file specimens of all materials evaluated.
7.9.1 When destructive tests are run, it is recommended that a sufficient number of file specimens be retained so that the property
of interest can be determined on unexposed file specimens each time exposed materials are evaluated.
NOTE 2—Since the stability of the file specimen may also be time-dependent, users are cautioned that over prolonged exposure periods, or where small
differences in the order of acceptable limits are anticipated, comparison of exposed specimens with the file specimen may not be valid. Nondestructive
instrumental measurements are recommended whenever possible.
7.10 Specimens should not ordinarily be removed from the exposure apparatus for more than 24 h, then returned for additional
tests, since this does not produce the same results on all materials as tests run without this type of interruption. When specimens
are removed from the exposure apparatus for 24 h or more, then returned for additional exposure, report the elapsed time as noted
under Section 10.
8. Procedure
8.1 Unless otherwise specified, operate the device using the following exposure cycle so that the allowable deviations about the
set points given with each set point below are within the specified limits specified in the corresponding entry. If the actual operating
conditions do not agree with the machine settings after the equipment has stabilized, discontinue the test and correct the cause of
the disagreement before continuing.
D3361/D3361M − 13 (2018)
NOTE 3—Each set point and the corresponding operational fluctuations given in this section represent an operational control point for equilibrium
conditions at a single location in the cabinet, which may not necessarily represent the uniform
...