ASTM E809-21

Standard Practice for Measuring Photometric Characteristics of Retroreflectors

SIGNIFICANCE AND USE
5.1 This practice describes procedures used to measure photometric quantities that relate to the visual perception of retroreflected light. The most significant usage is in the relation to the nighttime vehicle headlamp, retroreflector, and driver's eye geometry. For this reason the CIE Standard Source A is used to represent a tungsten vehicle headlamp and the receptor has the photopic, V (λ), spectral responsivity corresponding to the light adapted human eye. Although the geometry must be specified by the user, it will, in general, correspond to the relation between the vehicle headlamp, the retroreflector, and the vehicle driver's eye position.
SCOPE
1.1 This practice describes the general procedures for instrumental measurement of the photometric characteristics of retroreflective materials and retroreflective devices.  
1.2 This practice is a comprehensive guide to the photometry of retroreflectors but does not include geometric terms that are described in Practice E808.  
1.3 This practice describes the parameters that are required when stating photometric measurements in specific tests and specifications for retroreflectors.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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, 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: 31-Dec-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:E809 −21
Standard Practice for
1
Measuring Photometric Characteristics of Retroreflectors
This standard is issued under the fixed designation E809; 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.
3
1. Scope 2.2 CIE Documents:
CIE Publication No. 54.2Retroreflection—Definition and
1.1 This practice describes the general procedures for in-
Measurement
strumental measurement of the photometric characteristics of
CIE Publication DS 17.2/E:2009International Lighting Vo-
retroreflective materials and retroreflective devices.
cabulary
1.2 This practice is a comprehensive guide to the photom- CIE Publication No. 69-1987Methods of Characterizing
etryofretroreflectorsbutdoesnotincludegeometrictermsthat
Illuminance Meters and Luminance Meters
are described in Practice E808.
3. Terminology
1.3 This practice describes the parameters that are required
3.1 Terms and definitions in Terminology E284 and E808
when stating photometric measurements in specific tests and
specifications for retroreflectors. are applicable to this practice. In general, the terminology in
this practice agrees with that in CIE Publications DS 17.2/
1.4 The values stated in SI units are to be regarded as
E:2009 and 54.2.
standard. The values given in parentheses after SI units are
3.2 Definitions of Terms Specific to This Standard:
provided for information only and are not considered standard.
3.2.1 annular aperture, n—the difference between the an-
1.5 This standard does not purport to address all of the
gulardiametersoftheexternalboundarycircleandtheinternal
safety concerns, if any, associated with its use. It is the
boundary circle.
responsibility of the user of this standard to establish appro-
3.2.2 circular aperture, n—the angular diameter of a circu-
priate safety, health, and environmental practices and deter-
lar aperture surface.
mine the applicability of regulatory limitations prior to use.
3.2.3 goniometer, n—an instrument for measuring or setting
1.6 This international standard was developed in accor-
angles.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2.4 photopic receiver, n—a receiver of radiation with a
Development of International Standards, Guides and Recom-
spectral responsivity which conforms to the V (λ) distribution
mendations issued by the World Trade Organization Technical
of the CIE Photopic Standard Observer that is specified in
Barriers to Trade (TBT) Committee.
Practice E308.
3.2.5 receiver aperture, n—angular dimensions from the
2. Referenced Documents
retroreflector center to the entrance aperture or pupil of the
2
receiver.
2.1 ASTM Standards:
E284Terminology of Appearance
3.2.6 rectangular aperture, n—the angular height and width
E308PracticeforComputingtheColorsofObjectsbyUsing
of a rectangular aperture surface.
the CIE System
3.2.6.1 Discussion—The orientation of the sides of the
E808Practice for Describing Retroreflection
rectangular aperture surface should be supplied together with
the angular height and width.
3.2.7 reflected illuminance, E,n—illuminance at the re-
r
1
This practice is under the jurisdiction of ASTM Committee E12 on Color and ceiver measured on a plane perpendicular to the observation
Appearance and is the direct responsibility of Subcommittee E12.10 on Retrore-
axis.
flection.
3.2.7.1 Discussion—This quantity is used in the calculation
Current edition approved Jan. 1, 2021. Published February 2021. Originally
of the coefficient of luminous intensity,
approved in 1981. Last previous edition approved in 2013 as E809–08 (2013).
DOI: 10.1520/E0809-21.
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, PA 19428-2959. United States
1

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E809−21
2
R: R =(I/E )=(E d )/E , where d is the distance from the with the geometry of test, various photometric quantities
I I ' r '
retroreflector to the receptor. applicable to retroreflectors can be determined.
3.2.8 retroreflectometer aperture angles, n—the maxi
...

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: E809 − 08 (Reapproved 2013) E809 − 21
Standard Practice for
1
Measuring Photometric Characteristics of Retroreflectors
This standard is issued under the fixed designation E809; 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 practice describes the general procedures for instrumental measurement of the photometric characteristics of
retroreflective materials and retroreflective devices.
1.2 This practice is a comprehensive guide to the photometry of retroreflectors but does not include geometric terms that are
described in Practice E808.
1.3 This practice describes the parameters that are required when stating photometric measurements in specific tests and
specifications for retroreflectors.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this The values
given in parentheses after SI units are provided for information only and are not considered 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 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:
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E808 Practice for Describing Retroreflection
3
2.2 CIE Documents:
CIE Publication No. 54.2 Retroreflection—Definition and Measurement
CIE Publication DS 17.2/E:2009 International Lighting Vocabulary
CIE Publication No. 69-1987 Methods of Characterizing Illuminance Meters and Luminance Meters
1
This practice 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, 2013Jan. 1, 2021. Published January 2013February 2021. Originally approved in 1981. Last previous edition approved in 20082013 as
E809 – 08.E809 – 08 (2013). DOI: 10.1520/E0809-08R13.10.1520/E0809-21.
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.
3
Available from the CIE Webshop at http://www.cie.co.at.U.S. National Committee of the CIE (International Commission 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, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E809 − 21
3. Terminology
3.1 Terms and definitions in Terminology E284 and E808 are applicable to this practice. In general, the terminology in this practice
agrees with that in CIE Publications DS 17.2/E:2009 and 54.2.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 annular aperture, n—the difference between the angular diameters of the external boundary circle and the internal boundary
circle.
3.2.2 circular aperture, n—the angular diameter of a circular aperture surface.
3.2.3 goniometer, n—an instrument for measuring or setting angles.
3.2.4 photopic receiver, n—a receiver of radiation with a spectral responsivity which conforms to the V (λ) distribution of the CIE
Photopic Standard Observer that is specified in Practice E308.
3.2.5 receiver aperture, n—angular dimensions from the retroreflector center to the entrance aperture or pupil of the receiver.
3.2.6 rectangular aperture, n—the angular height and width of a rectangular aperture surface.
3.2.6.1 Discussion—
The orientation of the sides of the rectangular aperture surface should be supplied together with the angular height and width.
3.2.7 reflected illuminance, E , n—illuminance at the receiver measured on a plane perpendicular to the observation axis.
r
3.2.7.1 Discussion—
...