ASTM E2539-14
(Test Method)Standard Test Method for Multiangle Color Measurement of Interference Pigments
Standard Test Method for Multiangle Color Measurement of Interference Pigments
SIGNIFICANCE AND USE
5.1 This test method is designed to provide color data obtained from spectral reflectance factors at specific illumination and detection angles for interference pigments. Information presented in this test method is based upon data taken on materials exclusively pigmented with interference pigments.
5.2 These data can be used for acceptance testing, design purposes, research, manufacturing control, and quality control.
5.3 Specimens must be statistically representative of the end use.
5.4 Applicability of this test method for other materials, including combining interference pigments with absorbing and scattering pigments should be confirmed by the user.
SCOPE
1.1 This test method covers the instrumental requirements and required parameters needed to make instrumental color measurements of thin film interference pigments. This test method is designed to encompass interference pigments used in architectural applications, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and other applications.
1.2 Characterization of the optical behavior of materials colored with interference pigments requires measurement at multiple angles of illumination and detection.
1.3 Data taken utilizing this test method are quantitative and are appropriate for quality control of interference pigment color.
1.4 The measurement results are usually expressed as reflectance factors, tristimulus color values, or as CIE L*a*b* color coordinates and color difference.
1.5 The totality of data taken may not be necessary for evaluating mixtures also containing non-interference pigments. The committee is investigating and evaluating the appropriateness of this test method for those materials. It is the responsibility of the users to determine the applicability of this test method for their specific applications.
1.6 Interference pigments are typically evaluated for color and color appearance in a medium, such as paint or ink. The gonioapparent effect depends strongly on the physical and chemical properties of the medium. Some of the properties affecting color and color appearance include vehicle viscosity, thickness, transparency, and volume solids. As a general rule, for quality control purposes, interference pigments are best evaluated in a masstone product form. In some cases this product form may be the final product form, or more typically a qualified simulation of the intended product form (such as a paint drawdown) that in terms of color and appearance correlates to final product application.
1.7 This standard does not address the requirements for characterizing materials containing metal flake pigments. Measurements of the optical characteristics of materials containing metal flake pigments are described in Test Method E2194.
1.8 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.9 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.
General Information
Relations
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: E2539 − 14
Standard Test Method for
Multiangle Color Measurement of Interference Pigments
This standard is issued under the fixed designation E2539; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Objects that exhibit a change in color with different angles of illumination and view are said to be
“gonioapparent.” The tristimulus colorimetric values of gonioapparent objects are derived using the
spectral reflectance factors obtained from spectrometric measurements or colorimetric measurements
atvariousanglesofilluminationanddetection.Thetristimuluscolorimetricvaluesarecomputedusing
the spectral reflectance factors of the object, the CIE Standard Observer, and the spectral power
distribution of the illuminant, as described in Practice E308. This Test Method, E2539, specifies the
color measurement of interference pigments at various illumination and detection angles.
1. Scope chemical properties of the medium. Some of the properties
affecting color and color appearance include vehicle viscosity,
1.1 This test method covers the instrumental requirements
thickness, transparency, and volume solids. As a general rule,
and required parameters needed to make instrumental color
for quality control purposes, interference pigments are best
measurements of thin film interference pigments. This test
evaluated in a masstone product form. In some cases this
methodisdesignedtoencompassinterferencepigmentsusedin
product form may be the final product form, or more typically
architectural applications, automobiles, coatings, cosmetics,
a qualified simulation of the intended product form (such as a
inks, packaging, paints, plastics, printing, security, and other
paint drawdown) that in terms of color and appearance
applications.
correlates to final product application.
1.2 Characterization of the optical behavior of materials
1.7 This standard does not address the requirements for
colored with interference pigments requires measurement at
characterizingmaterialscontainingmetalflakepigments.Mea-
multiple angles of illumination and detection.
surements of the optical characteristics of materials containing
1.3 Datatakenutilizingthistestmethodarequantitativeand
metal flake pigments are described in Test Method E2194.
are appropriate for quality control of interference pigment
1.8 The values stated in SI units are to be regarded as the
color.
standard. The values given in parentheses are for information
1.4 The measurement results are usually expressed as re-
only.
flectance factors, tristimulus color values, or as CIE L*a*b*
1.9 This standard does not purport to address all of the
color coordinates and color difference.
safety concerns, if any, associated with its use. It is the
1.5 The totality of data taken may not be necessary for
responsibility of the user of this standard to establish appro-
evaluatingmixturesalsocontainingnon-interferencepigments.
priate safety and health practices and determine the applica-
The committee is investigating and evaluating the appropriate-
bility of regulatory limitations prior to use.
ness of this test method for those materials. It is the responsi-
bility of the users to determine the applicability of this test
2. Referenced Documents
method for their specific applications.
2.1 ASTM Standards:
1.6 Interference pigments are typically evaluated for color
E284Terminology of Appearance
and color appearance in a medium, such as paint or ink. The
E308PracticeforComputingtheColorsofObjectsbyUsing
gonioapparent effect depends strongly on the physical and
the CIE System
E805Practice for Identification of Instrumental Methods of
This test method is under the jurisdiction of ASTM Committee E12 on Color
and Appearance and is the direct responsibility of Subcommittee E12.12 on
Gonioapparent Color. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2014. Published November 2014. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2012 as E2539– 12. DOI: Standards volumeinformation,refertothestandard’sDocumentSummarypageon
10.1520/E2539-14. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2539 − 14
Color or Color-Difference Measurement of Materials 6. Environmental Conditions
E1164PracticeforObtainingSpectrometricDataforObject-
6.1 If the standard laboratory conditions listed below
Color Evaluation
change during the test or from test to test by an appreciable
E1345Practice for Reducing the Effect of Variability of
amount,theseconditionsmayreduceaccuracyandprecisionof
Color Measurement by Use of Multiple Measurements
this test method. In some cases these effects may only be
E1708Practice for Electronic Interchange of Color and
observed during the performance of the test.
Appearance Data
6.2 Factors affecting test results—The following factors are
E1767Practice for Specifying the Geometries of Observa-
known to affect the test results.
tion and Measurement to Characterize the Appearance of
6.2.1 Extraneous radiation—light from sources other than
Materials
theilluminator(s)andanynear-infrared(NIR)mustbeshielded
E2194Test Method for Multiangle Color Measurement of
from entering the test apparatus.
Metal Flake Pigmented Materials
6.2.2 Vibrations—mechanical oscillations that cause com-
E2480Practice for Conducting an Interlaboratory Study to
ponents of the apparatus to move relative to one another may
Determine the Precision of a Test Method with Multi-
cause errors in test results.
Valued Measurands
6.2.3 Thermal changes—temperature changes occurring
2.2 ISCC Publications:
during a test or differences in temperature between testing
Technical Report 2003–1Guide to Material Standards and
locations may affect calibration.
Their Use in Color Measurement
6.2.4 Power input fluctuations—large changes in the line
frequency or supply voltage may cause the apparatus to report
3. Terminology
erroneous results.
3.1 Terms and definitions in Terminology E284, and Prac-
6.3 Standardization—The system must allow for successful
tice E1767 and Test Method E2194 are applicable to this test
standardization. If the system cannot be standardized, consult
method. See Section 5 of E284 for “Specialized Terminology
the manufacturer’s user guide.
on Gonioapparent Phenomena.”
6.4 Controlling factors—Accuracy and precision can be
enhanced by controlling and regulating each factor within the
4. Summary of Test Method
constraintsoftheallowableexperimentalerror.Thevaluesand
4.1 This test method describes the instrumental geometries,
limitsforthesefactorsaretypicallydeterminedexperimentally
including abridged goniospectrometry, used to measure inter-
by the user.
ference pigments. Optical characterization requires color mea-
7. Apparatus
surementatmultipleilluminationandmultipledetectionangles
specified in this procedure. These sets of illumination and
7.1 Multiangle Spectrometer—Thistestmethodspecifiesthe
detection angles are specified in the test method. Standardiza-
required illumination and detection angles of multiangle spec-
tion and verification of the instrument used to measure these
trometers. These multiangle spectrometers are designed spe-
materials are defined. The requirements for selection of speci-
cifically to characterize the optical behavior of materials
mens and measurement procedures are provided. The results
coloredwithinterferencepigments.Geometriesarespecifiedin
are reported in terms of reflectance factors, CIE tristimulus
Section8.Thespectrometermayeitherbeagoniospectrometer
values,andothercolorcoordinatesystemsthatdefinethecolor
or an abridged goniospectrometer.
of the object. Expected values of precision are presented.
7.1.1 Bi-directional spectrometers or colorimeters with a
single angle of measurement; such as 45°:0° or 0°:45°, and
5. Significance and Use
spectrometers using hemispherical geometry cannot ad-
equately characterize the gonioapparency of these materials.
5.1 This test method is designed to provide color data
7.1.2 Multiangle spectrometers or colorimeters similar to
obtained from spectral reflectance factors at specific illumina-
those specified in Test Method E2194 cannot adequately
tion and detection angles for interference pigments. Informa-
characterize the gonioapparency of these materials.
tion presented in this test method is based upon data taken on
materials exclusively pigmented with interference pigments.
7.2 System Validation Materials—The precision and bias of
the entire measurement system, including calculation of CIE
5.2 These data can be used for acceptance testing, design
tristimulus values, should be determined by periodic measure-
purposes, research, manufacturing control, and quality control.
ment of known, calibrated, verification standards. These stan-
5.3 Specimensmustbestatisticallyrepresentativeoftheend
dards are supplied by instrument manufacturers or obtained
use. 4
separately.
5.4 Applicability of this test method for other materials,
8. Geometric Conditions
includingcombininginterferencepigmentswithabsorbingand
scattering pigments should be confirmed by the user. 8.1 The angles of illumination and detection are critical to
multiangle measurements of materials pigmented with inter-
ference pigments.
Available from the Inter-Society Color Council, 1191 Sunset Hills Road,
Reston, VA 20190, www.iscc.org. ISCC Technical Report 2003–1.
E2539 − 14
TABLE 2 Specified Geometries for Measuring the Color due to
8.2 Recommended Geometries:
Scattering or Orientation
8.2.1 All geometries cited here are uniplanar.
Illumination Detection Aspecular
8.2.2 Geometry Designation—The angles of illumination
Designation
Angle Angle Angle
and detection will be specified as illumination anormal angle,
45° -30° 15° 45°:-30° (as15°)*
detection anormal angle, and detection aspecular angle en-
45° -20° 25° 45°:-20° (as25°)
45° 0° 45° 45°:0° (as45°)*
closed in parenthesis. See Practice E1767. For the example of
45° 30° 75° 45°:30° (as75°)
an illumination angle of 45° and a detection angle of -30°
45° 65° 110° 45°:65°
(implying an aspecular angle of 15°), the geometry should be (as110°)*
designated as 45°:-30° (as 15°).
Note—The three angles designated with an asterisk (*), refer to preferred angles
for critical measurements as specified in Test Method E2194.
NOTE 1—For either illumination or detection, an anormal angle is
definedastheanglesubtendedatthepointofincidencebyagivenrayand Note—Given a geometric configuration, the reverse geometry is considered
equivalent, if all other components of the instrument design are equivalent.
the normal to the surface. An anormal angle is understood to be the
smaller of the two supplementary angles defined by the ray and the
normal. In a uniplanar geometry, a ray’s anormal angle has a positive sign
if that ray and the incident ray (illuminant ray) are on the same side of the
normal.
NOTE 2—The aspecular angle is the detection angle measured away 9.5 Specimen Physical Requirements:
from the specular direction, in the illumination plane. Positive values of
9.5.1 For test specimens that will be assessed visually, the
the aspecular angle are in the direction toward the illumination axis.
sizeshallbeatleast8by8cm(approximately3by3in.).This
8.2.3 For the reflectance-factor measurements of interfer-
specimen size is well suited for both visual assessment and
ence pigments, the instrument’s illumination and detection
instrumental measurement. See also 12.2.
angles shall conform to the angles as specified in Table 1.
NOTE 3—This recommendation for specimen size corresponds to the
These angles are required to measure the range of colors
physicalsizerequiredforobservationbytheCIE1964StandardObserver
exhibited by interference pigments.
(10°). The specimen must subtend at least 10° when being observed.
8.2.4 For the reflectance-factor measurement of materials
Observation usually occurs at approximately 45 cm (17.7 in.) from the
eye.
pigmented with metal-flake pigments and interference
pigments, additional information is provided by angles speci-
9.5.2 The surface of the specimen should be planar.
fied in Table 2. These angles are used to measure the color
9.6 Specimen Optical Requirements:
travel due to pigment flake-orientation effects and light scat-
9.6.1 Uniformity—Reference and test specimens should be
tering from the flake edges.
uniformincolorandappearance.Formaterialspigmentedwith
9. Test Specimen(s) interference or metallic pigments, measurements on different
locations on the sample are necessary to assess the degree of
9.1 Introduction—Measuredvaluesdependonthequalityof
non-uniformity. These data are also useful for determining the
the test specimens. The specimens must be statistically repre-
number of measurements necessary to achieve a value that is
sentative of the lot being tested and should meet the require-
statistically representative of the sample. See Practice E1345.
ments listed below. If the specimens do not meet these
Additionally, the samples-must be similar in appearance to
requirements, include this information in the report (Section
makemeaningfulobservations.Thereshouldbenoappearance
14).
of mottling or banding in the specimens.
9.2 Specimen Handling—Handle the specimens carefully.
9.6.2 Gloss—Specimens should be uniform and similar in
Touch them by their edges only. Never lay the measurement
gloss when viewed in a lighting booth.
surface of the specimen down on another surface or stack
9.6.3 Surface Texture—The specimens being compared
specimens without a protective medium between them as
should have substantially similar surface textures. Orange peel
recommended by the provider.
is a common example of surface texture.
9.3 Specimen Cleaning—If necessary, clean the specimens
9.6.4 Orientation—Consistent orientation of the specimen
following the providers’ recommended cleaning procedure.
forpresentationtothemeasuringinstrumentmustbecontrolled
for repeatable measurements. This is necessary to minimize
9.4 Specimen Conditioning—Allow specimens to stabilize
errors due to indiscriminate matching of the directionality of
inthemeasurementenvironmentforatimeperiodagreedtoby
the specimen to that of the instrument.
the parties concerned.
10. Instrument Standardization
TABLE 1 Specified Geometries for Measuring the Color Range
due to Interference
10.1 Standardization is necessary to adjust the instruments
Illumination Detecti
...
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: E2539 − 12 E2539 − 14
Standard Practice for Test Method for
Multiangle Color Measurement of Interference Pigments
This standard is issued under the fixed designation E2539; 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.
INTRODUCTION
Objects that exhibit a change in color with different angles of illumination and view are said to be
“gonioapparent.” The tristimulus colorimetric values of gonioapparent objects are derived using the
spectral reflectance factors obtained from spectrometric measurements or colorimetric measurements
at various angles of illumination and detection. The tristimulus colorimetric values are computed using
the spectral reflectance factors of the object, the CIE Standard Observer, and the spectral power
distribution of the illuminant, as described in Practice E308. This Practice, Test Method, E2539,
specifies the color measurement of interference pigments at various illumination and detection angles.
1. Scope
1.1 This practice covers the instrumental requirements and required parameters needed to make instrumental color
measurements of thin film interference pigments. This practice is designed to encompass interference pigments used in
architectural applications, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and other
applications.
1.2 Characterization of the optical behavior of materials colored with interference pigments requires measurement at multiple
angles of illumination and detection.
1.3 Data taken utilizing this practice are quantitative and are appropriate for quality control of interference pigment color.
1.4 The measurement results are usually expressed as reflectance factors, tristimulus color values, or as CIE L*a*b* color
coordinates and color difference.
1.5 The totality of data taken may not be necessary for evaluating mixtures also containing non-interference pigments. The
committee is investigating and evaluating the appropriateness of this practice for those materials. It is the responsibility of the users
to determine the applicability of this practice for their specific applications.
1.6 Interference pigments are typically evaluated for color and color appearance in a medium, such as paint or ink. The
gonioapparent effect depends strongly on the physical and chemical properties of the medium. Some of the properties affecting
color and color appearance include vehicle viscosity, thickness, transparency, and volume solids. As a general rule, for quality
control purposes, interference pigments are best evaluated in a masstone product form. In some cases this product form may be
the final product form, or more typically a qualified simulation of the intended product form (such as a paint drawdown) that in
terms of color and appearance correlates to final product application.
1.7 This standard does not address the requirements for characterizing materials containing metal flake pigments. Measurements
of the optical characteristics of materials containing metal flake pigments are described in Practice E2194.
1.8 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.9 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.
This practice test method is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.12 on
Gonioapparent Color.
Current edition approved April 1, 2012Nov. 1, 2014. Published May 2012November 2014. Originally approved in 2008. Last previous edition approved in 20082012 as
E2539 – 08.12. DOI: 10.1520/E2539-12.10.1520/E2539-14.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2539 − 14
2. Referenced Documents
2.1 ASTM Standards:
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E805 Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of Materials
E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation
E1345 Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements
E1708 Practice for Electronic Interchange of Color and Appearance Data
E1767 Practice for Specifying the Geometries of Observation and Measurement to Characterize the Appearance of Materials
E2194 Test Method for Multiangle Color Measurement of Metal Flake Pigmented Materials
E2480 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method with Multi-Valued
Measurands
2.2 ISCC Publications:
Technical Report 2003–1 Guide to Material Standards and Their Use in Color Measurement
3. Terminology
3.1 Terms and definitions in Terminology E284, and Practices E1767 and E2194 are applicable to this practice. See Section 5
of E284 for “Specialized Terminology on Gonioapparent Phenomena.”
4. Summary of Practice
4.1 This practice describes the instrumental geometries, including abridged goniospectrometry, used to measure interference
pigments. Optical characterization requires color measurement at multiple illumination and multiple detection angles specified in
this procedure. These sets of illumination and detection angles are specified in the practice. Standardization and verification of the
instrument used to measure these materials are defined. The requirements for selection of specimens and measurement procedures
are provided. The results are reported in terms of reflectance factors, CIE tristimulus values, and other color coordinate systems
that define the color of the object. Expected values of precision are presented.
5. Significance and Use
5.1 This practice is designed to provide color data obtained from spectral reflectance factors at specific illumination and
detection angles for interference pigments. Information presented in this test practice is based upon data taken on materials
exclusively pigmented with interference pigments.
5.2 These data can be used for acceptance testing, design purposes, research, manufacturing control, and quality control.
5.3 Specimens must be statistically representative of the end use.
5.4 Applicability of this practice for other materials, including combining interference pigments with absorbing and scattering
pigments should be confirmed by the user.
6. Environmental Conditions
6.1 If the standard laboratory conditions listed below change during the test or from test to test by an appreciable amount, these
conditions may reduce accuracy and precision of this test method. In some cases these effects may only be observed during the
performance of the test.
6.2 Factors affecting test results—The following factors are known to affect the test results.
6.2.1 Extraneous radiation—light from sources other than the illuminator(s) and any near-infrared (NIR) must be shielded from
entering the test apparatus.
6.2.2 Vibrations—mechanical oscillations that cause components of the apparatus to move relative to one another may cause
errors in test results.
6.2.3 Thermal changes—temperature changes occurring during a test or differences in temperature between testing locations
may affect calibration.
6.2.4 Power input fluctuations—large changes in the line frequency or supply voltage may cause the apparatus to report
erroneous results.
6.3 Standardization—The system must allow for successful standardization. If the system cannot be standardized, consult the
manufacturer’s user guide.
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.
Available from the Inter-Society Color Council, 1191 Sunset Hills Road, Reston, VA 20190, www.iscc.org.
E2539 − 14
6.4 Controlling factors—Accuracy and precision can be enhanced by controlling and regulating each factor within the
constraints of the allowable experimental error. The values and limits for these factors are typically determined experimentally by
the user.
7. Apparatus
7.1 Multiangle Spectrometer—This practice specifies the required illumination and detection angles of multiangle spectrom-
eters. These multiangle spectrometers are designed specifically to characterize the optical behavior of materials colored with
interference pigments. Geometries are specified in Section 8. The spectrometer may either be a goniospectrometer or an abridged
goniospectrometer.
7.1.1 Bi-directional spectrometers or colorimeters with a single angle of measurement; such as 45°:0° or 0°:45°, and
spectrometers using hemispherical geometry cannot adequately characterize the gonioapparency of these materials.
7.1.2 Multiangle spectrometers or colorimeters similar to those specified in Practice E2194 cannot adequately characterize the
gonioapparency of these materials.
7.2 System Validation Materials—The precision and bias of the entire measurement system, including calculation of CIE
tristimulus values, should be determined by periodic measurement of known, calibrated, verification standards. These standards are
supplied by instrument manufacturers or obtained separately.
8. Geometric Conditions
8.1 The angles of illumination and detection are critical to multiangle measurements of materials pigmented with interference
pigments.
8.2 Recommended Geometries:
8.2.1 All geometries cited here are uniplanar.
8.2.2 Geometry Designation—The angles of illumination and detection will be specified as illumination anormal angle,
detection anormal angle, and detection aspecular angle enclosed in parenthesis. See Practice E1767. For the example of an
illumination angle of 45° and a detection angle of -30° (implying an aspecular angle of 15°), the geometry should be designated
as 45°:-30° (as 15°).
NOTE 1—For either illumination or detection, an anormal angle is defined as the angle subtended at the point of incidence by a given ray and the normal
to the surface. An anormal angle is understood to be the smaller of the two supplementary angles defined by the ray and the normal. In a uniplanar
geometry, a ray’s anormal angle has a positive sign if that ray and the incident ray (illuminant ray) are on the same side of the normal.
NOTE 2—The aspecular angle is the detection angle measured away from the specular direction, in the illumination plane. Positive values of the
aspecular angle are in the direction toward the illumination axis.
8.2.3 For the reflectance-factor measurements of interference pigments, the instrument’s illumination and detection angles shall
conform to the angles as specified in Table 1. These angles are required to measure the range of colors exhibited by interference
pigments.
8.2.4 For the reflectance-factor measurement of materials pigmented with metal-flake pigments and interference pigments,
additional information is provided by angles specified in Table 2. These angles are used to measure the color travel due to pigment
flake-orientation effects and light scattering from the flake edges.
9. Test Specimen(s)
9.1 Introduction—Measured values depend on the quality of the test specimens. The specimens must be statistically
representative of the lot being tested and should meet the requirements listed below. If the specimens do not meet these
requirements, include this information in the report (Section 14).
ISCC Technical Report 2003–1.
TABLE 1 Specified Geometries for Measuring the Color Range
due to Interference
Illumination Detection Aspecular
Designation
Angle Angle Angle
45° -60° -15° 45°:-60° (as-15°)
45° -30° +15° 45°:-30° (as15°)
15° -30° -15° 15°:-30° (as-15°)
15° 0° +15° 15°:0° (as15°)
Note—This table gives the minimum geometries for the quality control applica-
tion. For other applications, additional geometries; such as 65°:-50° (as15°), may
be desirable or needed.
E2539 − 14
TABLE 2 Specified Geometries for Measuring the Color due to
Scattering or Orientation
Illumination Detection Aspecular
Designation
Angle Angle Angle
45° -30° 15° 45°:-30° (as15°)*
45° -20° 25° 45°:-20° (as25°)
45° 0° 45° 45°:0° (as45°)*
45° 30° 75° 45°:30° (as75°)
45° 65° 110° 45°:65°
(as110°)*
Note—The three angles designated with an asterisk (*), refer to preferred angles
for critical measurements as specified in Practice Test Method E2194.
Note—Given a geometric configuration, the reverse geometry is considered
equivalent, if all other components of the instrument design are equivalent.
9.2 Specimen Handling—Handle the specimens carefully. Touch them by their edges only. Never lay the measurement surface
of the specimen down on another surface or stack specimens without a protective medium between them as recommended by the
provider.
9.3 Specimen Cleaning—If necessary, clean the specimens following the providers’ recommended cleaning procedure.
9.4 Specimen Conditioning—Allow specimens to stabilize in the measurement environment for a time period agreed to by the
parties concerned.
9.5 Specimen Physical Requirements:
9.5.1 For test specimens that will be assessed visually, the size shall be at least 8 by 8 cm (approximately 3 by 3 in.). This
specimen size is well suited for both visual assessment and instrumental measurement. See also 12.2.
NOTE 3—This recommendation for specimen size corresponds to the physical size required for observation by the CIE 1964 Standard Observer (10°).
The specimen must subtend at least 10° when being observed. Observation usually occurs at approximately 45 cm (17.7 in.) from the eye.
9.5.2 The surface of the specimen should be planar.
9.6 Specimen Optical Requirements:
9.6.1 Uniformity—Reference and test specimens should be uniform in color and appearance. For materials pigmented with
interference or metallic pigments, measurements on different locations on the sample are necessary to assess the degree of
non-uniformity. These data are also
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.