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ASTM E809-94a(2000)

(Practice)

Standard Practice for Measuring Photometric Characteristics of Retroreflectors

Standard Practice for Measuring Photometric Characteristics of Retroreflectors

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 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
31-Dec-1999
ICS
17.180.20 - Colours and measurement of light
Technical Committee
E12 - Color and Appearance
Drafting Committee
E12.10 - Retroreflection
Current Stage
Ref Project

Relations

Replaced By
ASTM E809-02 - Standard Practice for Measuring Photometric Characteristics of Retroreflectors
Effective Date
10-Jun-2002

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ASTM E809-94a(2000) - Standard Practice for Measuring Photometric Characteristics of RetroreflectorsASTM E809-94a(2000) - Standard Practice for Measuring Photometric Characteristics of Retroreflectors
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ASTM E809-94a(2000) - Standard Practice for Measuring Photometric Characteristics of Retroreflectors
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Standards Content (Sample)

Designation: E 809 – 94a (Reapproved 2000)
Standard Practice for
1
Measuring Photometric Characteristics of Retroreflectors
This standard is issued under the fixed designation E 809; 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 (e) indicates an editorial change since the last revision or reapproval.
R 5 R /l
1. Scope
M I
3.2.2 coeffıcient of luminous intensity, R , n—of a retrore-
1.1 This practice describes the general procedures for in-
I
strumental measurement of the photometric characteristics of flector, ratio of the luminous intensity (I) of the retroreflector in
the direction of observation to the illuminance (E )atthe
retroreflective materials and retroreflective devices.
’
1.2 This practice is a comprehensive guide to the photom- retroreflector on a plane perpendicular to the direction of the
−1
incident light, expressed in candelas per lux (cd·lux ). R =(I/
etry of retroreflectors but does not include geometric terms that
I
are described in Practice E 808. E ).
’
1.3 This practice describes the parameters that are required 3.2.2.1 Discussion—Also called “coefficient of (retrore-
when stating photometric measurements in specific tests and flected) luminous intensity.” Recommended for determining
specifications for retroreflectors. the performance of retroreflectors such as button reflectors,
delineators, or automotive reflectors, since it depends on a unit
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the device and the area is not required. CIE uses the symbol R for
this quantity.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.2.3 coeffıcient of retroreflected luminance, R , n—ratio of
L
the luminance, L, of a projected surface to the normal illumi-
bility of regulatory limitations prior to use.
nance, E , at the surface on a plane normal to the incident
’
2. Referenced Documents
light, expressed in candelas per square metre per lux
−2 −1
2.1 ASTM Standards: (cd·m ·lx ).
2
E 284 Terminology of Appearance
R 5 ~L/E !
L ’
E 308 Practice for Computing the Colors of Objects by
2 3.2.4 coeffıcient of (retroreflected) luminous flux, R , n—the
F
Using the CIE System
ratio of the flux per unit solid angle F8/V8 coming from the
2
E 808 Practice for Describing Retroreflection
retroreflector measured at the observation point to the total flux
2.2 CIE Documents:
(F) incident on the effective retroreflective surface, expressed
CIE Publication No. 54—Retroreflection—Definition and
−1
in candelas per lumen (cd·lm ).
3
Measurement
R 5 ~F8/V8!/F5 I/F5 R /cos b
CIE Publication No. 17.4—International Lighting Vocabu- F A
3
lary
3.2.4.1 Discussion—The units for this photometric quantity,
candelas per lumen, are sometimes abbreviated as CPL.
3. Terminology
3.2.5 coeffıcient of retroreflection, R , n—of a plane ret-
A
3.1 Terms and definitions in Terminology E 284 are appli-
roreflecting surface, the ratio of the coefficient of luminous
cable to this practice. In general, the terminology in this
intensity (R ) of a plane retroreflecting surface to its area (A)
I
−1 −2
practice agrees with that in CIE Publications 17.4 and 54.
expressed in candelas per lux per square metre (cd·lx ·m ).
3.2 Definitions:
R 5 R /A!
~
A I
3.2.1 coeffıcient of line retroreflection, R , of a retroreflect-
M
3.2.5.1 Discussion—The equivalent inch-pound units for
ing stripe, n—the ratio of the coefficient of luminous intensity
coefficient of retroreflection are candelas per foot candle per
( R ) of a retroreflecting stripe to its length (l), expressed in
I
−1 −1
square foot. The SI and inch-pound units are numerically
candelas per lux per metre (cd·lx ·m ).
equal. An equivalent term used for coefficient of retroreflection
is specific intensity per unit area, with symbol SIA or the CIE
1
This practice is under the jurisdiction of ASTM Committee E12 on Color and
symbol R8. The term coefficient of retroreflection and the
Appearance and is the direct responsibility of Subcommittee E12.10 on Retrore-
symbol R along with the SI units of candelas per lux per
A
flection.
square meter are recommended by ASTM.
Current edition approved April 15, 1994. Published June 1994. Originally
published as E 809 – 81. Last previous edition E 809 – 94. 3.2.6 datum mark, n—in retroreflection, an indication on the
2
Annual Book of ASTM Standards, Vol 06.01.
3
Available from USNC/CIE Publications Office; TLA Lighting Consultants,
Inc., 77 Pond St., Salem, MA 01970.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E 809
retroreflector that is used to define the orientation of the near its exposed surface (for example, retroreflective sheeting,
retroreflector with respect to rotation abou
...

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1.1 This guide is intended for use in establishing the operating characteristics of a visual display unit (VDU), such as a cathode ray tube (CRT). Those characteristics define the relationship between the digital information supplied by a computer, which defines an image, and the resulting spectral radiant exitance and CIE tristimulus values. The mathematical description of this relationship can be used to provide a nearby device-independent model for the accurate display of color and colored images on the VDU. The CIE tristimulus values referred to here are those calculated from the CIE 1931 2° standard colorimetric (photopic) observer.  
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1.1 This guide is intended for use in selecting terminology, measurement scales, and instrumentation for describing or evaluating such appearance characteristics as glossiness, opacity, lightness, transparency, and haziness in terms of reflected or transmitted light. This guide does not consider the spectral variations responsible for color, but the geometric variables described herein can importantly affect instrumentally measured values of color. This guide is general in scope rather than specific as to instrument or material.  
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ASTM E2301-12(2022)(Test Method)
Standard Test Method for Daytime Colorimetric Properties of Fluorescent Retroreflective Sheeting and Marking Materials for High Visibility Traffic Control and Personal Safety Applications Using 45°:Normal Geometry

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5.1 This test method provides procedures for obtaining tristimulus values, luminance factors and chromaticity coordinates of fluorescent-retroreflective materials by bispectral colorimetry using a 45:0 or 0:45 optical measuring system.  
5.2 The CIE 1931 (2°) standard observer is used to calculate the colorimetric properties of fluorescent-retroreflective sheeting and markings used in daytime high visibility traffic control and personal safety applications because in practice these materials are primarily viewed from a distance where they subtend less than 4° of the visual field.  
5.3 This test method is applicable to object-color specimens of any gloss level.  
5.4 Due to the retroreflective properties of these materials the colorimetric data may not be suitable for use in computer colorant formulation.  
5.5 This test method is suitable for quality control testing of fluorescent-retroreflective sheeting and marking materials.
Note 1: Separation of the fluorescence and reflectance components from the total colorimetric properties provides useful and meaningful information to evaluate independently the luminescent and diffuse reflective efficiency and consistency of these materials.  
5.6 This test method is the referee method for determining the conformance of fluorescent-retroreflective sheeting and marking materials to standard daytime colorimetric specifications.
SCOPE
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ASTM E1477-98a(2022)(Test Method)
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5.4 The use of this test method for determining the luminous reflectance factor is required by Classification E1264.
SCOPE
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