ASTM E2630-08(2013)

Standard Test Method for Luminance Ratio of a Fluorescent Specimen using a Narrow Band Source (Withdrawn 2022)

SIGNIFICANCE AND USE
5.1 The test method is suitable for the development, specification and quality control testing of fluorescent and non-fluorescent coatings that are intended to be inspected for defects under Specification E2501 illumination.
SCOPE
1.1 This test method covers the instrumental measurement of the luminance ratio of a fluorescent coating or sheet sample when illuminated by a narrow band source.  
1.2 This test method is generally applicable to any coating or sheeting material having combined fluorescent and reflective properties, where the fluorescence is activated by 405 nm light.  
1.3 This test method is intended as a companion to Specification E2501 to support the development and specification of industrial coatings that are used in a system for detection of coating defects when inspected with the Specification E2501 light source. This test method establishes a quantitative measure of the optical property of a coating that correlates to its ability to enhance defect contrast under the specified inspection light source.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This test method covers the instrumental measurement of the luminance ratio of a fluorescent coating or sheet sample when illuminated by a narrow band source.
Formerly under the jurisdiction of Committee E12 on Color and Appearance, this test method was withdrawn in January 2022 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 30-Jun-2013
• Withdrawal Date: 11-Jan-2022
• ICS: 93.080.40 - Street lighting and related equipment
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.05 - Fluorescence

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E2630 − 08 (Reapproved 2013)
Standard Test Method for
Luminance Ratio of a Fluorescent Specimen using a Narrow
Band Source
This standard is issued under the fixed designation E2630; 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.
1. Scope D5162Practice for Discontinuity (Holiday) Testing of Non-
conductive Protective Coating on Metallic Substrates
1.1 This test method covers the instrumental measurement
E179Guide for Selection of Geometric Conditions for
of the luminance ratio of a fluorescent coating or sheet sample
Measurement of Reflection and Transmission Properties
when illuminated by a narrow band source.
of Materials
1.2 This test method is generally applicable to any coating
E284Terminology of Appearance
orsheetingmaterialhavingcombinedfluorescentandreflective
E1164PracticeforObtainingSpectrometricDataforObject-
properties,wherethefluorescenceisactivatedby405nmlight.
Color Evaluation
1.3 This test method is intended as a companion to Speci- E1488GuideforStatisticalProcedurestoUseinDeveloping
and Applying Test Methods
fication E2501 to support the development and specification of
industrial coatings that are used in a system for detection of E2501Specification for Light Source Products for Inspec-
tion of Fluorescent Coatings
coating defects when inspected with the Specification E2501
light source. This test method establishes a quantitative mea-
2.2 Other Documents:
sure of the optical property of a coating that correlates to its
ISO 10527:2007(E)⁄CIE S 014-1⁄E:2006 CIE Standard
abilitytoenhancedefectcontrastunderthespecifiedinspection
Colorimetric Observers
light source.
CIE Publication 69:1987Methods of characterizing illumi-
nance meters and luminance meters: Performance, char-
1.4 The values stated in SI units are to be regarded as
acteristics and specifications
standard. No other units of measurement are included in this
standard.
2.3 SSPC:
SSPC-SP 10/NACE No. 2Near-White Blast Cleaning
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3.1 The definitions contained in Guide E179, Terminology
bility of regulatory limitations prior to use.
E284, and Practice E1164 are applicable to this test method.
3.2 The definitions for coating defects, discontinuity,
2. Referenced Documents
holiday, and pinhole are contained in Practice D5162.
2.1 ASTM Standards:
3.3 Definitions of Terms Specific to This Standard:
D2805Test Method for Hiding Power of Paints by Reflec-
3.3.1 luminance ratio, n—luminance of the sample under a
tometry
given narrow band 405 nm source divided by the luminance of
D4356Practice for Establishing Consistent Test Method
3 a 25% reflecting Lambertian diffuser under the same narrow
Tolerances (Withdrawn 2007)
band 405 nm source.
This test method is under the jurisdiction of ASTM Committee E12 on Color
4. Summary of Test Method
and Appearance and is the direct responsibility of Subcommittee E12.05 on
4.1 Thistestmethodprovidesaprocedureformeasuringthe
Fluorescence.
CurrenteditionapprovedJuly1,2013.PublishedJuly2013.Originallyapproved
luminanceratioofafluorescent,reflectivecoatingcomparedto
ε1
in 2008. Last previous edition approved in 2008 as E2630 – 08 . DOI: 10.1520/
E2630-08R13.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM AvailablefromU.S.NationalCommitteeoftheCIE(InternationalCommission
Standards volume information, refer to the standard’s Document Summary page on on Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 Pond
the ASTM website. St., Salem, MA 01970, http://www.cie-usnc.org.
3 5
The last approved version of this historical standard is referenced on Available from Society for Protective Coatings (SSPC), 40 24th St., 6th Floor,
www.astm.org. Pittsburgh, PA 15222-4656, http://www.sspc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2630 − 08 (2013)
a 25% reflecting Lambertian diffuser, which is similar to steel mismatch correction factors with respect to the illuminator
grit blasted to an SSPC-SP 10/NACE No. 2 near-white metal describedin6.1shallbedeterminedfortheluminancemeterto
blast. at least 1 part in 100 when measuring the non-fluorescent
reflectance standard and the fluorescent sample.
4.2 This test method requires the use of a luminance meter,
a narrow band 405 nm source and a calibrated non-fluorescent
NOTE 5—The ratio of the spectral mismatch correction factors may be
determined by using a non-fluorescent reflectance standard calibrated
reflectance standard.
under the source described in 6.1 and a fluorescent sample similar to the
5. Significance and Use test sample, which are calibrated for luminance ratio under the source
described in 6.1.
5.1 The test method is suitable for the development, speci-
NOTE 6—An informational appendix (Appendix X1) is provided that
fication and quality control testing of fluorescent and non-
briefly summarizes the method for calculating the spectral mismatch
fluorescent coatings that are intended to be inspected for correction factors or the ratio of such.
defects under Specification E2501 illumination.
6.2.3 If the luminance meter is spectrally based, the out-of-
-5
band stray light rejection shall be better than 1 ×10 .
6. Apparatus
6.2.4 The field-of-view of the luminance meter and the
6.1 Illuminator:
distance from the sample surface shall be such that the viewed
6.1.1 The source shall have a peak wavelength of 405 nm 2
region shall be larger than 2.5 cm with no dimension smaller
(61 nm), a symmetric unimodal distribution with a full width
than 1.3 cm.
half maximum of 16 nm (62 nm). The shape of the spectral
NOTE7—Theviewingareaoftheluminancemeterdependsonthefield
distribution shall be triangular, Gaussian or isosceles trapezoi-
of view and the distance from the sample. The viewing area for a circular
dal where the width of the peak shall be less than one sixth the
aperture is calculated by using the following equation:
size of the base.
viewing area 5 ~ tan ~v/2!·d! ·π/cos~45°! (1)
NOTE 1—A uniform or rectangular distribution does not meet this
condition. where:
NOTE 2—An informational appendix (Appendix X1) is provided that
v = field of view of the luminance meter and
briefly summarizes the reasons for the choices of tolerances in this test
d = distance between the luminance meter and the test sample.
method.
6.2.5 The luminance meter shall be insensitive to the
6.1.2 The integrated irradiance over the wavelength range
polarization of the light.
490 to 760 nm shall be less than 0.01% of the integrated
6.2.6 Thelinearityoftheluminancemeterovertherangeof
irradiance over the wavelength range 380 to 760 nm.
measurements shall be within 1%. Correction factors may be
NOTE 3—The light from 490 to 760 nm is typically from fluorescence
used to ensure a linear response.
generated in the light source. This light is heavily weighted by the
6.2.7 The stability of the luminance meter over the duration
luminousefficacyfunction,V(λ),resultinginlargeerrorsintheluminance
of the measurements shall not vary more than 1%.
ratio measurement. The fluorescence can be eliminated with a blue-green
6.2.8 The out-of-view sensitivity, described in CIE Publica-
colored glass filter that has an internal transmittance at a reference
thickness of 1 mm greater than 0.90 at 405 nm and less than 0.05 across tion 69, of the luminance meter shall be less than 0.5%.
the wavelength range of 500 to 680 nm.
6.3 Non-fluorescent Reflectance Standard:
6.1.3 The source shall produce a minimum irradiance suf-
6.3.1 The non-fluorescent reflectance standard shall be cali-
ficient to ensure a signal-to-noise ratio of 100 to 1 for the
brated in a 0°:45° geometry for luminous reflectance under the
luminance meter described in 6.2.
source described in 6.1with an expanded uncertainty (k=2)of
less than 1%.
NOTE 4—An irradiance of 10 W/m is typically sufficient.
6.1.4 Theilluminatedareashallbeatleasttwicetheviewing NOTE 8—The magnitude of the luminous reflectance of the non-
fluorescent reflectance standard is somewhat arbitrary, because it is
area of the luminance meter. The minimum viewing area is
normalized to 0.25 in the calculations shown in 10.1. Typically, the
specified in 6.2.4.
magnitude of the luminous reflectance of the non-fluorescent reflectance
6.1.5 The source irradiance shall be stable to 1% over the
standard is above 0.9 in order to have a larger signal-to-noise ratio.
time frame of the measurements.
6.3.2 Thenon-fluorescentreflectancestandardshallhavean
6.1.6 The illuminance on the sample surface shall be uni-
integrated radiance over the wavelength range 490 to 760 nm
form within 65% of the average illuminance normal to the
lessthan0.05%oftheintegratedradianceoverthewavelength
source. The illuminator may be collimated or not.
range 380 to 760 nm under the illuminator specified in 6.1.
6.2 Luminance Meter:
6.3.3 Thenon-fluorescentreflectancestandardshallproduce
6.2.1 The responsivity and range of the luminance meter
a diffuse distribution when illuminated.
shall be sufficient so that readings of both the non-fluorescent
reflectance standard and the fluorescent sample are measured
7. Test Specimen
with a resolution of at least 1 part in 100.
7.1 Prepare coating in accordance with Test Method D2805
6.2.2 If the luminance meter is filter based, the spectral
for drawdown sample for hiding power by reflectometry.
responsivity of the luminance meter shall match that of the
1931 CIE Standard Photopic Observer. 7.2 Alternately, prepare by spraying or drawing down on a
(ISO 10527:2007(E)⁄CIE S 014-1⁄E:2006) The individual black substrate that has a maximum reflectance of 1% and
spectral mismatch correction factors or the ratio of spectral does not fluoresce.
E2630 − 08 (2013)
7.3 The coating dry film thickness shall be within the 9.3 The distance between the luminance meter and the
manufacturers recommended range for the intended applica- sample surface shall be set such that the field-of-view defines
tion. a region of interest that is over illuminated by the illuminator
according to 6.1.4.
8. Calibration and Standardization
9.4 Measure the non-fluorescent reflectance standard with
8.1 Theluminancemetershallbecalibratedaccordingtothe
the luminance meter.
manufacturer’sspecification.Theindividualspectralmismatch
9.4.1 Handle the samples carefully; avoid scratching or
correction factors or the ratio of spectral mismatch correction
touching the area to be measured. To remove dust and lint use
factors with respect to the illuminator described in 6.1 shall be
dry, filtered, pressurized nitrogen.
determined for the luminance meter when measuring the
9.5 Block the illuminator such that the non-fluorescent
non-fluorescentreflectancestandardandthefluorescentsample
reflectance standard is not illuminated and measure the dark
to at least 1 part in 100. (See Note 5.)
non-fluorescent reflectance standard signal.
8.2 The non-fluorescent reflectance standard shall be cali-
9.6 Position the fluorescent sample and measure the fluo-
brated as described in 6.3.1.
rescent sample with the luminance meter.
9. Procedure
9.7 Blocktheilluminatorsuchthatthefluorescentsampleis
not illuminated and measure the dark fluorescent sample
9.1 Fig. 1 provides a schematic for the measurement align-
signal.
ment. The measurements shall be conducted in the dark such
that the signal measured in 9.5 is less than 1 part of the signal
9.8 Calculate the luminance ratio using Eq 2 specified in
measured in 9.4.
10.1
9.2 Position the illuminator described in 6.1 such that the
10. Calculation
angle between the direction of illumination and the normal to
10.1 For each fluorescent sample calculate the luminance
the specimen surface shall not exceed 2°. Position the lumi-
nance meter such that the angle between the direction of ratio using the following equation:
viewing and the normal to the specimen surface shall be 45 6 B
~s 2 s ! F ρ
d
B
R 5 · · (2)
2°.
L
s 2 s F 0.25
~ !
P P,d P
NOTE 9—Fluorescent coatings inspected under a 405 nm illuminator
where:
enhance defect detection through two mechanisms: (1) enhanced contrast
B
R = luminance ratio,
between the fluorescent coating and nonfluorescent substrate; and (2)
L
uniform coating color and brightness regardless of the viewing angle.The s = luminance signal for the fluorescent sample,
second mechanism is important for inspecting the fluorescent coating
s = dark luminance signal for the fluorescent sample,
d
along welds, in corners and on edges. Under white light inspection,
s = luminance signal for the non-fluorescent reflectance
P
defects in these areas are obscured by glare and shadows. With a 405 nm
standard,
inspectionlight,darkspotsareunambiguouslyinterpretedasdefects.This
s = dark luminance signal for the non-fluorescent reflec-
P,d
effect is primarily responsible for the increased productivity and accuracy
tance standard,
reportedbycoatingsinspectorsinfieldtrials.Theluminanceratioata45°
F = spectralmismatchcorrectionfactorforthefluorescent
viewing angle correlates with this property better than that at a smaller
viewing angle.
sample under the illuminator,
F = spectral mismatch correction factor for the non-
P
fluorescent reflectance standard under the illuminator,
and
B
ρ = luminous reflectance of the non-fluorescent reflec-
tance standard under the illuminator.
11. Report
11.1 The report shall contain the following information.
11.2 Sample identification including any commercial desig-
nation and manufacturer lot number.
11.3 Date of measurement.
11.4 Identification of the luminous reflectance of the non-
fluorescent reflectance standard.
11.5 Description of apparatus.
11.5.1 Peakwavelengthandfullwidthhalfmaximumofthe
illuminator.
11.5.2 Make and model number of luminance meter.
11.5.3 Distance between luminance meter and test speci-
men.
FIG. 1 A Schematic of the Measurement Alignment 11.5.4 Filed-of-view of the luminance meter.
E2630 − 08 (2013)
11.6 The luminance ratio. reflectancestandardandthefluorescentsample.Byshiftingthe
spectral power distribution several nanometers toward the blue
12. Precision and Bias
and red regions of the spectrum and recalculating the spectral
12.1 Precision—The repeatability and the reproducibility of mismatch correction factors a de
...