ASTM D4061-13

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Designation: D4061 − 94 (Reapproved 2006) D4061 − 13
Standard Test Method for
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Retroreflectance of Horizontal Coatings
This standard is issued under the fixed designation D4061; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method describes the instrumental measurement of the retroreflective properties of horizontal surfacing materials,
such as traffic stripe paint systems, traffic tapes, and traffic surface symbols.
1.2 Specimen preparation, size, and shape must be determined and specified by the user of this test method. Likewise, the user
must specify the observation and entrance angles to be used (see Fig. 1).
1.3 The geometric requirements of this test method are based on materials for which the relative retroreflectance changes less
than approximately 50 % over the observation angle range from 0.2 to 0.5°. This is illustrated in Fig. 2.
1.4 This test method is a laboratory test and requires a facility that can be darkened sufficiently so that stray light does not affect
the test results. This facility must be capable of housing the required 15-m test distance.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
standard. No other units of measurement are included in this standard.
1.6 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.
2. Referenced Documents
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2.1 ASTM Standards:
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E808 Practice for Describing Retroreflection
E809 Practice for Measuring Photometric Characteristics of Retroreflectors
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2.2 CIE Publication:
No. 54 Retroreflection Definition and Measurement
3. Terminology
3.1 The terms and definitions in Terminology E284 apply to this test method.
3.2 Definitions:
3.2.1 coeffıcient of retroreflected luminance, R , n—ratio of the luminance, L, of a projected surface to the normal illuminance,
L
−2 −1
E , at the surface on a plane normal to the incident light, expressed in candelas per square metre per lux (cd·m ·lx ).
'
R 5 L/E (1)
~ !
L '
3.2.2 datum mark, n—in retroreflection, an indication on the retroreflector that is used to define the orientation of the
retroreflector with respect to rotation about the retroreflector axis.
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This test method is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.10 on Retroreflection.
Current edition approved July 1, 2006July 1, 2013. Published July 2006August 2013. Originally approved in 1989. Last previous edition approved in 20002006 as
D4061 – 94 (2000).(2006). DOI: 10.1520/D4061-94R06.10.1520/D4061-13.
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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’s Document Summary page on the ASTM website.
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Available from U.S. National Committee of the CIE (International Commission on Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 Pond St.,
Salem, MA 01970.01970, http://www.cie-usnc.org.
3.2.2.1 Discussion—
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4061 − 13
NOTE 1—Includes observation angle α, entrance angle β, viewing angle ν , co-viewing angle ν , and co-entrance angle β . The retroreflector axis,
a c c
illumination axis, and observation axis all lie in the same plane.
FIG. 1 Diagram Illustrating Geometry for Measurement of Horizontal Coatings Specimens
FIG. 2 Illustration of Typical Rate of Change of Retroreflectance Versus Observation Angle for Horizontal Retroreflective Material Mea-
sured at 86° Entrance Angle
The datum mark must not lie on the retroreflector axis.
3.2.3 entrance angle, β, n—in retroreflection, angle between the illumination axis and the retroreflector axis.
3.2.3.1 Discussi
...