ASTM D4061-94(2006)
(Test Method)Standard Test Method for Retroreflectance of Horizontal Coatings
Standard Test Method for Retroreflectance of Horizontal Coatings
SIGNIFICANCE AND USE
The quantity coefficient of retroreflected luminance is a measure of the reflected luminance in the direction of the observer. This is the light returned by the retroreflective surface to the observer from the source, which in practice is the vehicle headlamp.
This test method may be used as a measure of the nighttime performance of horizontally applied surfacing materials used on highway surfaces for lane markings and other traffic control purposes.
Since this test method is a laboratory procedure, test specimens must be prepared so that they can be mounted on the specimen holder. Specimens measured by this laboratory method may be used as transfer standards for the calibration of portable instrumentation.
Specimen selection and preparation may significantly influence the results of this test method.
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 ).
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 .
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.
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.
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Designation:D4061 −94(Reapproved2006)
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.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E809Practice for Measuring Photometric Characteristics of
Retroreflectors
1.1 This test method describes the instrumental measure-
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ment of the retroreflective properties of horizontal surfacing 2.2 CIE Publication:
materials, such as traffic stripe paint systems, traffic tapes, and No. 54Retroreflection Definition and Measurement
traffic surface symbols.
3. Terminology
1.2 Specimen preparation, size, and shape must be deter-
mined and specified by the user of this test method. Likewise, 3.1 The terms and definitions inTerminology E284 apply to
theusermustspecifytheobservationandentranceanglestobe this test method.
used (see Fig. 1).
3.2 Definitions:
1.3 The geometric requirements of this test method are 3.2.1 coeffıcient of retroreflected luminance, R ,n—ratio of
L
based on materials for which the relative retroreflectance the luminance, L, of a projected surface to the normal
changes less than approximately 50% over the observation illuminance, E , at the surface on a plane normal to the
'
incident light, expressed in candelas per square metre per lux
angle range from 0.2 to 0.5°. This is illustrated in Fig. 2.
−2
−1
(cd·m ·lx ).
1.4 This test method is a laboratory test and requires a
R 5 L/E (1)
facilitythatcanbedarkenedsufficientlysothatstraylightdoes ~ !
L '
not affect the test results. This facility must be capable of
3.2.2 datum mark, n—in retroreflection,anindicationonthe
housing the required 15-m test distance.
retroreflector that is used to define the orientation of the
retroreflector with respect to rotation about the retroreflector
1.5 The values stated in SI units are to be regarded as the
axis.
standard. The values given in parentheses are for information
3.2.2.1 Discussion—The datum mark must not lie on the
only.
retroreflector axis.
1.6 This standard does not purport to address all of the
3.2.3 entrance angle,β, n—in retroreflection,anglebetween
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- the illumination axis and the retroreflector axis.
3.2.3.1 Discussion—For plane retroreflective surfaces, the
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. entrance angle is no larger than 90°.
3.2.3.2 Discussion—Theentranceanglemaybedividedinto
2. Referenced Documents components β and β . This is described in Practice E808.In
1 2
2 this test method only the component β is used. Therefore,
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2.1 ASTM Standards:
where only the entrance angle β is specified the convention
E284Terminology of Appearance
used is β =0 and β = β.
2 1
E308PracticeforComputingtheColorsofObjectsbyUsing
3.2.4 illumination axis, n— in retroreflection,alinefromthe
the CIE System
effective center of the source aperture to the retroreflector
E808Practice for Describing Retroreflection
center.
3.2.5 normal illuminance, E —theilluminanceonaretrore-
'
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This test method is under the jurisdiction of ASTM Committee E12 on Color
flective surface measured in the plane that passes through the
and Appearance and is the direct responsibility of Subcommittee E12.10 on
retroreflector center and is perpendicular to the illumination
Retroreflection.
−2
axis; measured in lux (lumens·m ).
CurrenteditionapprovedJuly1,2006.PublishedJuly2006.Originallyapproved
in 1989. Last previous edition approved in 2000 as D4061–94(2000). DOI:
10.1520/D4061-94R06.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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contact ASTM Customer Service at service@astm.org. 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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4061−94(2006)
illumination;forexample,thedirectionoftheroadonwhichor
with respect to which the retroreflector is intended to be
positioned. In testing horizontal road markings the retroreflec-
tor axis is usually the normal to the test surface.
3.2.11 rotation angle, ϵ,n—angle indicating the orientation
ofthespecimenwhenitisrotatedaboutaselectedaxisfixedin
it (for plane specimens, usually the
...
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