ASTM E809-02

Standard Practice for Measuring Photometric Characteristics of Retroreflectors

SIGNIFICANCE AND USE
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’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’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 E 808.
1.3 This practice describes the parameters that are required when stating photometric measurements in specific tests and specifications for retroreflectors.
1.4 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.

General Information

• Status: Historical
• Publication Date: 09-Jun-2002
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.10 - Retroreflection

Relations

• Replaces: ASTM E809-94a(2000) - Standard Practice for Measuring Photometric Characteristics of Retroreflectors
• Effective Date: 10-Jun-2002
• Replaced By: ASTM E809-08 - Standard Practice for Measuring Photometric Characteristics of Retroreflectors
• Effective Date: 01-Jan-2008
• Referred By: ASTM D4383-21 - Standard Specification for Plowable, Raised Retroreflective Pavement Markers
• Effective Date: 10-Jun-2002
• Referred By: ASTM E284-22 - Standard Terminology of Appearance
• Effective Date: 10-Jun-2002
• Referred By: ASTM D4280-18 - Standard Specification for Extended Life Type, Nonplowable, Raised Retroreflective Pavement Markers
• Effective Date: 10-Jun-2002
• Referred By: ASTM E2540-16(2022) - Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.5 Degree Observation Angle
• Effective Date: 10-Jun-2002
• Referred By: ASTM E1710-18 - Standard Test Method for Measurement of Retroreflective Pavement Marking Materials with CEN-Prescribed Geometry Using a Portable Retroreflectometer
• Effective Date: 10-Jun-2002
• Referred By: ASTM D8379/D8379M-21 - Standard Practice for Evaluating Nighttime Retroreflective Sheeting Effectiveness Using Positive-Contrast Textual Sign Scenario Performance Analysis
• Effective Date: 10-Jun-2002
• Referred By: ASTM E179-17(2022) - Standard Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials
• Effective Date: 10-Jun-2002
• Referred By: ASTM E1696-15(2022) - Standard Test Method for Field Measurement of Raised Retroreflective Pavement Markers Using a Portable Retroreflectometer
• Effective Date: 10-Jun-2002
• Referred By: ASTM D4061-13(2018) - Standard Test Method for Retroreflectance of Horizontal Coatings
• Effective Date: 10-Jun-2002
• Referred By: ASTM E811-09(2020)e1 - Standard Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime Conditions
• Effective Date: 10-Jun-2002
• Referred By: ASTM E2302-03a(2022) - Standard Test Method for Measurement of the Luminance Coefficient Under Diffuse Illumination of Pavement Marking Materials Using a Portable Reflectometer
• Effective Date: 10-Jun-2002
• Referred By: ASTM E1709-16(2022) - Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer at a 0.2 Degree Observation Angle
• Effective Date: 10-Jun-2002
• Referred By: ASTM E3165-18 - Standard Test Method for Nighttime Retroreflected Chromaticity of Retroreflective Sheeting
• Effective Date: 10-Jun-2002

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: E 809 – 02
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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 retroreflectometer aperture angles —the maximum
1.1 This practice describes the general procedures for in-
angular diameter of the pencil of light (see Fig. 1).
strumental measurement of the photometric characteristics of
3.2.1.1 Discussion—In practice the illumination arrives at
retroreflective materials and retroreflective devices.
the retroreflector center within a narrow pencil of light sur-
1.2 This practice is a comprehensive guide to the photom-
rounding the illumination axis and the light reflected to the
etryofretroreflectorsbutdoesnotincludegeometrictermsthat
photoreceptor is contained within another narrow pencil. The
are described in Practice E808.
distribution of light within such pencils is the “aperture”
1.3 This practice describes the parameters that are required
functionandthemaximumangulardiameterofthepencilisthe
when stating photometric measurements in specific tests and
“aperture angle.” It is generally assumed that the aperture
specifications for retroreflectors.
functions are rotationally symmetrical and even uniform, but
1.4 This standard does not purport to address all of the
this is often false, especially for illumination.
safety concerns, if any, associated with its use. It is the
3.2.2 retroreflector aperture surface—the aperture surface
responsibility of the user of this standard to establish appro-
of a retroreflector is given by the retroreflector itself, or by a
priate safety and health practices and determine the applica-
diaphragm enclosing part of the retroreflector.
bility of regulatory limitations prior to use.
3.2.3 retroreflector (or specimen) aperture—angulardimen-
2. Referenced Documents
sions from the source point of reference to the aperture surface
of the retroreflector (or specimen).
2.1 ASTM Standards:
2
3.2.3.1 Discussion—As the source and receiver are gener-
E284 Terminology of Appearance
ally close to each other, distinction is not made between
E308 Practice for Computing the Colors of Objects by
2
aperture angles seen from the source and receiver.When using
Using the CIE System
2
collimated optics where the source and receiver are at virtual
E808 Practice for Describing Retroreflection
infinity, the retroreflector aperture is virtually naught. The
2.2 CIE Documents:
retroreflector aperture describes the maximum variation of the
CIE Publication No. 54.2, Retroreflection—Definition and
3
entrance angle of the aperture surface of the retroreflector.
Measurement
3.2.4 circular aperture—the angular diameter of a circular
CIE Publication No. 17.4, International Lighting Vocabu-
3
aperture surface.
lary
3.2.5 annular aperture—the difference between the angular
CIE Publication No. 69-1987, Methods of Characterizing
3
diameters of the external boundary circle and the internal
Illuminance Meters and Luminance Meters
boundary circle.
3. Terminology
3.2.6 rectangular aperture—theangularheightandwidthof
a rectangular aperture surface.
3.1 Terms and definitions in Terminology E284 and E808
3.2.6.1 Discussion—The orientation of the sides of the
are applicable to this practice. In general, the terminology in
rectangular aperture surface should be supplied together with
thispracticeagreeswiththatinCIEPublications17.4and54.2.
the angular height and width.
3.2.7 source aperture—angular dimensions from the ret-
1
This practice is under the jurisdiction ofASTM Committee E12 on Color and
roreflector center to the exit aperture stop or pupil of the light
Appearance and is the direct responsibility of Subcommittee E12.10 on Retrore-
source.
flection.
3.2.8 receiver aperture—angular dimensions from the ret-
Current edition approved June 10, 2002. Published August 2002. Originally
published as E809–81. Last previous edition E809–94a(2000). roreflector center to the entrance aperture or pupil of the
2
Annual Book of ASTM Standards, Vol 06.01.
receiver.
3
Available from USNC/CIE Publications Office; TLA Lighting Consultants,
Inc., 77 Pond 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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E809–02
6. Uses and Applications
6.1 Coeffıcient of Retroreflection— This quantity is used to
specifytheperformanceofretroreflectivesheeting.Itconsiders
the retroreflector as an apparent point source whose re
...