ASTM E1247-12(2023)
(Practice)Standard Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
Standard Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
SIGNIFICANCE AND USE
4.1 Several standards, including Practices E991, E1164, and Test Methods E1331, E1348 and E1349, require either the presence or absence of fluorescence exhibited by the specimen for correct application. This practice provides spectrophotometric procedures for identifying the presence of fluorescence in materials.
4.2 This practice is applicable to all object-color specimens, whether opaque, translucent, or transparent, meeting the requirements for specimens in the appropriate standards listed in 2.1. Translucent specimens should be measured by reflectance, with a standard non-fluorescent backing material, usually but not necessarily black, placed behind the specimen during measurement.
4.3 This practice requires the use of a spectrophotometer in which the spectral distribution of the illumination on the specimen can be altered by the user in one of several ways. The modification of the illumination can either be by the insertion of optical filters between the illuminating source and the specimen, without interfering with the detection of the radiation from the specimen, or by interchange of the illuminating and detecting systems of the instrument or by scanning of both the illuminating energy and detection output as in the two-monochromator method.
4.4 The confirmation of the presence of fluorescence is made by the comparison of spectral curves, color difference, or single parameter difference such as ΔY between the measurements.
Note 2: In editions of E1247 – 92 and earlier, the test of fluorescence was the two sets of spectral transmittances or radiance factor (reflectance factors) differ by 1 % of full scale at the wavelength of greatest difference.
4.5 Either bidirectional or hemispherical instrument geometry may be used in this practice. The instrument must be capable of providing either broadband (white light) irradiation on the specimen or monochromatic irradiation and monochromatic detection.
4.6 This practice describes methods to detect the...
SCOPE
1.1 This practice provides spectrophotometric methods for detecting the presence of fluorescence in object-color specimens.
Note 1: Since the addition of fluorescing agents (colorants, whitening agents, etc.) is often intentional by the manufacturer of a material, information on the presence or absence of fluorescent properties in a specimen may often be obtained from the maker of the material.
1.2 This practice requires the use of a spectrophotometer that both irradiates the specimen over the wavelength range from 340 nm to 700 nm and allows the spectral distribution of illumination on the specimen to be altered as desired.
1.3 Within the above limitations, this practice is general in scope rather than specific as to instrument or material.
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
Relations
Standards Content (Sample)
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.
Designation: E1247 − 12 (Reapproved 2023)
Standard Practice for
Detecting Fluorescence in Object-Color Specimens by
Spectrophotometry
This standard is issued under the fixed designation E1247; 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 E308 Practice for Computing the Colors of Objects by Using
the CIE System
1.1 This practice provides spectrophotometric methods for
E313 Practice for Calculating Yellowness and Whiteness
detecting the presence of fluorescence in object-color speci-
Indices from Instrumentally Measured Color Coordinates
mens.
E991 Practice for Color Measurement of Fluorescent Speci-
NOTE 1—Since the addition of fluorescing agents (colorants, whitening
mens Using the One-Monochromator Method
agents, etc.) is often intentional by the manufacturer of a material,
E1164 Practice for Obtaining Spectrometric Data for Object-
information on the presence or absence of fluorescent properties in a
Color Evaluation
specimen may often be obtained from the maker of the material.
E1331 Test Method for Reflectance Factor and Color by
1.2 This practice requires the use of a spectrophotometer
Spectrophotometry Using Hemispherical Geometry
that both irradiates the specimen over the wavelength range
E1348 Test Method for Transmittance and Color by Spec-
from 340 nm to 700 nm and allows the spectral distribution of
trophotometry Using Hemispherical Geometry
illumination on the specimen to be altered as desired.
E1349 Test Method for Reflectance Factor and Color by
1.3 Within the above limitations, this practice is general in
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
scope rather than specific as to instrument or material.
Geometry
E2152 Practice for Computing the Colors of Fluorescent
1.4 This standard does not purport to address all of the
Objects from Bispectral Photometric Data
safety concerns, if any, associated with its use. It is the
E2153 Practice for Obtaining Bispectral Photometric Data
responsibility of the user of this standard to establish appro-
for Evaluation of Fluorescent Color
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3. Terminology
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3.1 The definitions in Terminology E284, Practices E991,
ization established in the Decision on Principles for the E2152, and E2153 are applicable to this practice.
Development of International Standards, Guides and Recom-
4. Significance and Use
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.1 Several standards, including Practices E991, E1164, and
Test Methods E1331, E1348 and E1349, require either the
2. Referenced Documents
presence or absence of fluorescence exhibited by the specimen
2.1 ASTM Standards: for correct application. This practice provides spectrophoto-
metric procedures for identifying the presence of fluorescence
D2244 Practice for Calculation of Color Tolerances and
Color Differences from Instrumentally Measured Color in materials.
Coordinates
4.2 This practice is applicable to all object-color specimens,
E284 Terminology of Appearance
whether opaque, translucent, or transparent, meeting the re-
quirements for specimens in the appropriate standards listed in
2.1. Translucent specimens should be measured by reflectance,
This practice is under the jurisdiction of ASTM Committee E12 on Color and
with a standard non-fluorescent backing material, usually but
Appearance and is the direct responsibility of Subcommittee E12.05 on Fluores-
cence.
not necessarily black, placed behind the specimen during
Current edition approved Nov. 1, 2023. Published November 2023. Originally
measurement.
approved in 1988. Last previous edition approved in 2017 as E1247 – 12 (2017).
DOI: 10.1520/E1247-12R23.
4.3 This practice requires the use of a spectrophotometer in
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
which the spectral distribution of the illumination on the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
specimen can be altered by the user in one of several ways. The
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. modification of the illumination can either be by the insertion
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1247 − 12 (2023)
of optical filters between the illuminating source and the tages and shortcomings depending on the wavelength and
specimen, without interfering with the detection of the radia- intensity of the fluorescent emission and the instrumentation
tion from the specimen, or by interchange of the illuminating available to the user.
and detecting systems of the instrument or by scanning of both
6.2 Two-Monochromator Method: This method requires a
the illuminating energy and detection output as in the two-
colorimetric measuring instrument that is equipped with two
monochromator method.
separate monochromators: the first, the illumination
4.4 The confirmation of the presence of fluorescence is
monochromator, irradiates the specimen with monochromatic
made by the comparison of spectral curves, color difference, or
light and the second, the viewing monochromator, analyzes the
single parameter difference such as ΔY between the measure-
radiation leaving the specimen. A two-dimensional array of
ments.
bispectral photometric values is obtained by setting the illumi-
nation monochromator at a series of fixed wavelengths (μ) in
NOTE 2—In editions of E1247 – 92 and earlier, the test of fluorescence
the illumination band of the specimen, and for each μ, using the
was the two sets of spectral transmittances or radiance factor (reflectance
factors) differ by 1 % of full scale at the wavelength of greatest difference. viewing monochromator to record readings for each wave-
length (λ) in the specimen’s viewing range. The resulting array,
4.5 Either bidirectional or hemispherical instrument geom-
once properly corrected, is known as the Donaldson matrix,
etry may be used in this practice. The instrument must be
and the value of each element (μ,λ) of this array is the
capable of providing either broadband (white light) irradiation
Donaldson radiance factor (D(μ,λ)). The reflection values are
on the specimen or monochromatic irradiation and monochro-
confined to the diagonal of the matrix, and these diagonal
matic detection.
values are equal to the spectral reflectance factor of the
4.6 This practice describes methods to detect the presence
specimen. Therefore, the presence of fluorescence is demon-
of fluorescence only. It does not address the issue of whether
strated by non-zero off-diagonal elements. The measurement
the fluorescence makes a significant or insignificant contribu-
procedures for this method are given in detail in Practice
tion to the colorimetric properties of the specimen for any
E2153.
given application. The user must determine the practical
6.3 Filter Methods: Filter methods follow the general pro-
significance of the effect of fluorescence on the color measure-
cedure of making a measurement of spectral radiance factor
ment.
using a spectrometer with broad band illumination, then adding
one or more filters to remove the fluorescence-excitation
5. Instrumental Requirements
energy and measuring the spectral radiance factor under the
5.1 This practice requires instrumentation meeting the fol-
modified illumination. The comparison of the resulting spectral
lowing requirements.
curves shows the presence or absence of fluorescence. If the
5.1.1 The instrument source shall provide sufficient irradia-
exclusion of the excitation energy results in a difference in the
tion energy at the sample port to excite fluorescent emission, if
remaining part of the curve, fluorescence is present and must
present.
be considered in the measurement procedures. If no difference
5.1.2 The instrument must provide one of the following is found, then fluorescence is not an issue in the measurement
illumination/viewing combinations: of that specimen.
5.1.2.1 Monochromatic illumination and monochromatic
6.3.1 UV-Blocking Method—This procedure is typically
viewing (that is, a two-monochromator spectrophotometer
used for detecting the presence of optical brighteners, such as
sometimes called a bispectrometer or spectrofluorimeter).
in white paper and textiles.
5.1.2.2 Polychromatic illumination and monochromatic
6.3.1.1 Calibrate the instrument as required by the manu-
viewing.
facturer. (See Practice E1164 and the appropriate test method
5.1.2.3 Reversible illumination/viewing to allow both poly-
for the instrument geometry.)
chromatic illumination with monochromatic viewing and
NOTE 4—Since the measurement will be used to detect fluorescence, it
monochromatic illumination with polychromatic viewing.
should be considered that fluorescence might be present, therefore the
5.1.3 The instrument and associated computer software
calibration procedure should include adjusting the instrument’s illumina-
shall allow the standardization/calibration of the instrument tor to conform as closely as possible to D65 including the UV region of
the spectrum. In some commercial instruments this may be accomplished
using user modified standardization/calibration values, which
by calibrating by whiteness index or the UV profile.
is a requirement for using any of the filter methods described
in this practice.
6.3.1.2 Measure the specimen, obtaining either a table or a
graph of spectral transmittance or reflectance factor versus
NOTE 3—Repeatable and accurate application of this practice requires
wavelength.
specialized instrumentation. Some commercial one-monochromator spec-
trometers are limited in their ability to allow for the insertion of optical
6.3.1.3 Insert a long-wavelength bandpass filter between the
filters and re-standardization with the filter in place as required in this
illuminating source and the specimen. Select the cutoff wave-
procedure.
length of the filter according to the color of the specimen using
the recommendation in Table 1 as a guide.
6. Procedures
(a) For spectrophotometers equipped for illumination by
6.1 There are three general types of procedures to detect the means of an integrating sphere, the filter must be placed
presence of fluorescence instrumentally. Each has its advan- between the illuminating source and the illumination entrance
E1247 − 12 (2023)
TABLE 1 Edge-Position and Emission Wavelengths
method. In the filter reduction method 3 to 5 filters in the
Edge-Position Minimum Emission region of suspected fluorescence are used. In this method 10 to
Sample Color
Wavelength, nm Wavelength, nm
12 filters are used to measure the entire visible spectrum.
White or blue 440 400
Follow the procedure in 6.3.1.1 – 6.3.1.5 for measurements
Green 510 480
with each filter. Then examine the difference between the
Yellow 540 480
Orange 620 550 curves. Refer to the referenced literature for complete details of
Red 650 560
the application of this method.
6.4 Two-Mode Method: The two-mode method also com-
pares the results of two measurements. However in this case,
port of the sphere for reflectance measurement. For transmit-
instead of using a filter to exclude the excitation energy, the
tance measurement, the filter must be placed between the procedure relies on the fact that the fluorescence will show up
illuminating source and the specimen.
as increased values at the emission wavelengths when in the
(b) For spectrophotometers equipped for illumination by mode involving polychromatic illumination, but not necessar-
means of bidirectional geometry, the filter must be placed
ily so when in the mode involving monochromatic illumina-
between the illuminating source and the specimen. tion. The two spectral curves will always have different shapes
6.3.1.4 Repeat the calibration in accordance with 6.3.1
when there is fluorescence (6), (7). Therefore, instruments in
modifying the calibration values to be 0 below the cutoff of the which the position of the source and detector can be switched
filter.
can be used to detect the presence of fluorescence.
6.3.1.5 Repeat the measurement in accordance with 6.3.1.2.
6.4.1 Set the instrument for polychromatic illumination and
calibrate it, following the instrument manufacturer’s instruc-
NOTE 5—This method employing only one cut-off filter is most
tions. (See Practice E1164 and the appropriate test method for
commonly used when measuring white materials where optical brighten-
ing is suspected.
the instrument geometry.)
6.3.2 Fluorescence-Weakening Method: In the fluorescence- 6.4.2 Measure the specimen, obtaining either a table or a
weakening method two different bandpass filters are used and graph of spectral transmittance or reflectance factor versus
three measurements are compared (1). One filter is chosen to
wavelength.
remove all the fluorescence-exciting wavelengths (flu-
6.4.3 Set the instrument for monochromatic illumination
orescence-killing filter), and the second filter is chosen to
and calibrate it in a manner similar to that given in 6.3.1.
remove incident illumination about 20 nm to 40 nm shorter
6.4.4 Measure the specimen in accordance with 6.3.2.
than the first filter (fluorescence-weakening filter). Use the
procedure in 6.3.1.1 and 6.3.1.2 for the measurement without
7. Interpretation of Results
any filter in place. Then use the procedures in 6.3.1.3 – 6.3.1.5
7.1 The confirmation of the presence of fluorescence is
for the measurements with each of the filters. Refer to the
referenced literature for complete details of the application of made by examining the Donaldson matrix or by the compari-
son of spectral curves at the wavelength of maximum
this method.
6.3.3 Filter Reduction Method: Several linear long band- deviation, color difference, or single parameter difference such
as ΔY or Whiteness Index (WI) between the measurements. If
pass filters are placed, one at a time, in the light path between
the source and the specimen. Usually 3 to 5 filters are enough you have used the two-monochromator method follow step 7.2
or 7.5, or both. If you are using the comparison of spectral
to estimate the reflected radiance factor (2). The same proce-
dure is used to measure th
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