ASTM E810-20

Standard Test Method for Coefficient of Retroreflection of Retroreflective Sheeting Utilizing the Coplanar Geometry

SIGNIFICANCE AND USE
5.1 Measurements made by this test method are related to visual observations of retroreflective sheeting as seen by the human eye when illuminated by tungsten-filament light sources such as a motor vehicle headlamp.  
5.2 The values determined relate to the visual effects for a given geometric configuration as specified by the user of the test method. This test method has been found useful for tests at observation angles between 0.1 and 2.0° (observation angles between 0.1° and 0.2° may be achieved by careful design of source and receiver aperture configuration), and at entrance angles up to 60°. It has been used to determine coefficient of retroreflection values as low as 0.1 cd·lx−1 · m−2, but for values less than 1 cd·lx−1 · m−2 special attention must be given to the responsivity of the receiver and to the elimination of very small amounts of stray light.
SCOPE
1.1 This test method describes an instrument measurement of the retroreflective performance of retroreflective sheeting.  
1.2 The user of this test method must specify the entrance and observation angles to be used, and may specify the rotation angles.  
1.3 This test method is intended as a laboratory test and requires a facility that can be darkened sufficiently so that stray light does not affect the test results. The testing apparatus must be able to achieve the coplanar geometry.  
1.4 Portable and bench retroreflection measuring equipment may be used to determine RA values provided the geometry and appropriate substitution standard reference panels, measured in accordance with this test method, are utilized. In this case the methods of Procedure B in Practice E809 apply. Additional information on the use of portable retroreflectometers may be found in Test Method E1709.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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

• Status: Published
• Publication Date: 30-Sep-2020
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.10 - Retroreflection

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:E810 −20
Standard Test Method for
Coefficient of Retroreflection of Retroreflective Sheeting
1
Utilizing the Coplanar Geometry
This standard is issued under the fixed designation E810; 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 E177Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
1.1 This test method describes an instrument measurement
E284Terminology of Appearance
of the retroreflective performance of retroreflective sheeting.
E308PracticeforComputingtheColorsofObjectsbyUsing
1.2 The user of this test method must specify the entrance
the CIE System
andobservationanglestobeused,andmayspecifytherotation
E691Practice for Conducting an Interlaboratory Study to
angles.
Determine the Precision of a Test Method
E808Practice for Describing Retroreflection
1.3 This test method is intended as a laboratory test and
requiresafacilitythatcanbedarkenedsufficientlysothatstray E809Practice for Measuring Photometric Characteristics of
Retroreflectors
light does not affect the test results.The testing apparatus must
be able to achieve the coplanar geometry. E1709Test Method for Measurement of Retroreflective
Signs Using a Portable Retroreflectometer at a 0.2 Degree
1.4 Portable and bench retroreflection measuring equipment
Observation Angle
maybeusedtodetermine R valuesprovidedthegeometryand
A
2.2 Other Document:
appropriatesubstitutionstandardreferencepanels,measuredin
CIE Publication No 54 Retroreflection—Definition and
accordance with this test method, are utilized. In this case the
3
Measurement
methods of Procedure B in Practice E809 apply. Additional
information on the use of portable retroreflectometers may be
3. Terminology
found in Test Method E1709.
3.1 The terms and definitions in Terminology E284 and
1.5 This standard does not purport to address all of the
Practice E808 apply to this test method.
safety concerns, if any, associated with its use. It is the
3.2 Definitions:
responsibility of the user of this standard to establish appro-
3.2.1 coeffıcient of retroreflection, R —of a plane retrore-
priate safety, health, and environmental practices and deter-
A
flecting surface, the ratio of the coefficient of luminous
mine the applicability of regulatory limitations prior to use.
intensity (R) to the area (A), expressed in candelas per lux per
1.6 This international standard was developed in accor-
I
−1 −2
square metre (cd·lx ·m ). R = R/A.
dance with internationally recognized principles on standard-
A I
3.2.1.1 Discussion—The equivalent inch–pound units for
ization established in the Decision on Principles for the
coefficient of retroreflection are candelas per foot-candle per
Development of International Standards, Guides and Recom-
−1 −2
square foot (cd·fc ·ft ). The SI and inch pound units are
mendations issued by the World Trade Organization Technical
numerically equal, because the units of R reduce to 1/sr. An
Barriers to Trade (TBT) Committee.
A
equivalenttermusedforcoefficientofretroreflectionisspecific
2. Referenced Documents intensity per unit area, with symbol SIAor the CIE symbol R'.
2 Thetermcoefficientofretroreflectionandthesymbol R along
A
2.1 ASTM Standards:
with the SI units of candelas per lux per square meter
−1 −2
(cd·lx ·m ) are recommended by ASTM.
3.2.1.2 Discussion—R is a useful engineering quantity for
1
A
This test method is under the jurisdiction of ASTM Committee E12 on Color
determining the photometric performance of such retroreflec-
and Appearance and is the direct responsibility of Subcommittee E12.10 on
Retroreflection.
tive surfaces as highway delineators or warning devices. R
A
Current edition approved Oct. 1, 2020. Published November 2020. Originally
may also be used to determine the minimum area of retrore-
approved in 1981. Last previous edition approved in 2013 as E810–03 (2013).
flective sheeting necessary for a desired level of photometric
DOI: 10.1520/E0810-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on AvailablefromU.S.NationalCommitteeoftheCIE(InternationalCommission
the ASTM website. on Illumination) (http://www.cie-usnc.org) or the CIE (cie.co.at) Webshop.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
1

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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: E810 − 03 (Reapproved 2013) E810 − 20
Standard Test Method for
Coefficient of Retroreflection of Retroreflective Sheeting
1
Utilizing the Coplanar Geometry
This standard is issued under the fixed designation E810; 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 an instrument measurement of the retroreflective performance of retroreflective sheeting.
1.2 The user of this test method must specify the entrance and observation angles to be used, and may specify the rotation angles.
1.3 This test method is intended as a laboratory test and requires a facility that can be darkened sufficiently so that stray light does
not affect the test results. The testing apparatus must be able to achieve the coplanar geometry.
1.4 Portable and bench retroreflection measuring equipment may be used to determine R values provided the geometry and
A
appropriate substitution standard reference panels, measured in accordance with this test method, are utilized. In this case the
methods of Procedure B in Practice E809 apply. Additional information on the use of portable retroreflectometers may be found
in Test Method E1709.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
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
E1709 Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.2 Degree Observation
Angle
1
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 Jan. 1, 2013Oct. 1, 2020. Published January 2013November 2020. Originally approved in 1981. Last previous edition approved in 20082013
as E810 – 03 (2008).(2013). DOI: 10.1520/E0810-03R13.10.1520/E0810-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E810 − 20
2.2 Other Document:
3
CIE Publication No 54 Retroreflection—Definition and Measurement
3. Terminology
3.1 The terms and definitions in Terminology E284 and Practice E808 apply to this test method.
3.2 Definitions:
3.2.1 coeffıcient of retroreflection, R —of a plane retroreflecting surface, the ratio of the coefficient of luminous intensity (R ) to
A I
−1 −2
the area (A), expressed in candelas per lux per square metre (cd·lx ·m ). R = R /A.
A I
3.2.1.1 Discussion—
−1 −2
The equivalent inch–pound units for coefficient of retroreflection are candelas per foot-candle per square foot (cd·fc ·ft ). The
SI and inch pound units are numerically equal, because the units of R reduce to 1/sr. An equivalent term used for coefficient of
A
retroreflection is specific intensity per unit area, with symbol SIA or the CIE symbol R'. The term coefficient of retroreflection and
−1 −2
the symbol R along with the SI units of candelas per lux per square meter (cd·lx ·m ) are recommended by ASTM.
A
3.2.1.2 Discussion—
R is a useful engineering quantity for determining the photometric performance of such retroreflective surf
...