ASTM E3165-18

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:E3165 −18
Standard Test Method for
Nighttime Retroreflected Chromaticity of Retroreflective
Sheeting
This standard is issued under the fixed designation E3165; 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 2. Referenced Documents
1.1 This test method describes the instrumental determina- 2.1 ASTM Standards:
tion of the nighttime retroreflected chromaticity coordinates of D4956 Specification for Retroreflective Sheeting for Traffic
retroreflective sheeting. Control
E284 Terminology of Appearance
1.2 This method includes a procedure based on tristimulus
E308 PracticeforComputingtheColorsofObjectsbyUsing
filter colorimetery and a procedure based on spectral measure-
the CIE System
ments.
E691 Practice for Conducting an Interlaboratory Study to
1.3 A single set of test geometries (using 0.33° observation
Determine the Precision of a Test Method
angle and 5° entrance angle) and apertures are described in this
E808 Practice for Describing Retroreflection
method.
E809 Practice for Measuring Photometric Characteristics of
Retroreflectors
1.4 The resulting chromaticity coordinates are for use with
the CIE 1931 chromaticity system utilizing CIE Illuminant A. E810 Test Method for Coefficient of Retroreflection of
Retroreflective Sheeting Utilizing the Coplanar Geometry
1.5 If measurements and calculations are required for other
E811 Practice for Measuring Colorimetric Characteristics of
sources of illumination, or geometries, or other materials, the
Retroreflectors Under Nighttime Conditions
user is referred to the general practice described in Practice
2.2 CIE and ISO Documents:
E811.
CIE Publication 15:2004 Colorimetry
1.6 The values stated in SI units are to be regarded as
CIE Technical Report 54.2 Retroreflection: Definition and
standard. No other units of measurement are included in this
Measurement
standard.
CIETechnicalReport72 GuidetothePropertiesandUsesof
1.7 This standard does not purport to address all of the Retroreflectors at Night
safety concerns, if any, associated with its use. It is the
ISO 11664–1:2007 (CIE S 014–1/E:2006) Colorimetry—
responsibility of the user of this standard to establish appro- Part 1: CIE Standard Colorimetric Observers
priate safety, health, and environmental practices and deter- ISO 11664–2:2007 (CE S 014–2/E:2006) Colorimetry—Part
mine the applicability of regulatory limitations prior to use. 2: CIE Standard Illuminants
1.8 This international standard was developed in accor- 2.3 U. S. Federal Regulations:
dance with internationally recognized principles on standard- US Code of Federal Regulations (CFR) Title 23: Highways:
ization established in the Decision on Principles for the Part 655—Traffic Operations, Subpart F—Traffic Control
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Barriers to Trade (TBT) Committee.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
AvailablefromU.S.NationalCommitteeoftheCIE(InternationalCommission
This test method is under the jurisdiction of ASTM Committee E12 on Color on Illumination), C/o Alan Laird Lewis, 282 E. Riding, Carlisle, MA 01741,
and Appearance and is the direct responsibility of Subcommittee E12.10 on http://www.cie-usnc.org.
Retroreflection. Available from U.S. Government Printing Office, Superintendent of
Current edition approved July 1, 2018. Published September 2018. DOI: Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
10.1520/E3165-18. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3165−18
Devices on Federal-Aid and Other Streets and Highways 6. Apparatus
6.1 The apparatus consists of a light source, a receptor
3. Terminology
(tristimulus or spectral) and the geometric arrangement (either
in a photometric range or an optically-reduced design for
3.1 The terms and definitions inTerminology E284 apply to
laboratory bench or field use).
this test method.
6.2 The light source shall closely approximate the spectral
3.2 Definitions:
distributionofCIEIlluminantA(acorrelatedcolortemperature
3.2.1 chromaticity coordinates, n—the ratio of each of the
of 2856 K, see Practice E308).
tristimulus values of any viewed light to the sum of the three.
NOTE 1—Non-fluorescent samples may be illuminated with non-
3.2.1.1 Discussion—Chromaticity coordinates in the CIE
Illuminant A (for example, broadband) light sources using this method.
The CIE Illuminant A light source is considered the referee condition for
1931 system of color specification are designated by x, y, and
this test method.
z.
6.3 The receptor shall closely approximate the CIE tristimu-
3.2.2 spectral coeffıcient of retroreflection R (λ), n—the
A
lus functions when used. For spectral testing the dispersing
ratio of the spectral coefficient of radiant intensity R (λ) of the
I
elementsshallprovidearangefrom380to740nmwitha5nm
retroreflector for a given geometrical configuration to the area
increment anda5nm bandpass. (For spectral measurements
A of the retroreflector.
made by systems with increment and bandpass ≤5 nm, for
R λ
~ !
I
example, array detectors, integration techniques are acceptable
R ~λ! 5
A
A
to obtain the equivalent ofa5nm bandpass).
NOTE 2—Other bandpass specifications may be used. For example, the
3.2.3 spectral coeffıcient of retroreflected radiant intensity
precision and bias data contained in Section 12 were collected by
R (λ), n—the ratio of the spectral radiant intensity I (λ) of the
I e
equipment having either 5 nm or 10 nm bandpass. The 5 nm bandpass is
retroreflector for a given geometrical configuration to the
considered the referee condition for this test method.
spectral irradiance E (λ) of the incident light source at the
e
7. Sampling, Test Specimens, and Test Units
retroreflector on a plane perpendicular to the illumination axis.
7.1 Multiple samples shall be gathered from the retroreflec-
I ~λ!
e
R λ 5
~ !
tive sheeting material in a manner so as to constitute a
I
E λ
~ !
e'
representative sampling. One example of a sampling procedure
is described in Section 9 of Specification D4956. Deviations
4. Summary of Test Method
from this procedure shall be described in the report.
4.1 The general procedure is to illuminate the test specimen
7.2 The reference test specimen in this procedure shall be
with the specified source, in the prescribed geometry, and
200 6 100 mm by 200 6 100 mm in size.The entire specimen
analyze the reflected light using the calculation in DIE Publi-
to be measured shall be illuminated.
cation 15.
NOTE 3—The sample dimensions specified above refer to the referee
laboratory measurement. Field measurements may dictate other sample
4.2 The geometric arrangement can be either a longer-
dimension requirements. In all cases, the minimum illuminated area shall
distance photometric range or an optically-reduced equivalent
be a circle having a 25 mm diameter.
geometry for laboratory bench or field work.
7.3 Retroreflective sheeting materials may have color char-
4.3 The measurements may be performed using a substitu-
acteristics that vary slowly with changes in observation,
tion standard calibrated by an appropriate calibration labora-
entrance, and orientation angle. Care should be taken to ensure
tory. Measurements are then relative to this standard.
careful preparation of the sample and placement in the mea-
surement system.
5. Significance and Use
7.4 Retroreflective sheeting may produce small “rainbow
like” diffraction effects at some observation angles. If there is
5.1 The results of this test method are used to assess
concern that these effects are present, then the maximum fixed
conformance of retroreflective sheeting to the nighttime color
aperturesize(10minofarc;see9.2)istobeusedasthereferee
requirements of industry standards and government
configuration. In general, measurements at apertures less than
regulations, such as Specification D4956 and U.S. Code of
the maximum size will provide no significant effect on the
Federal Regulations Title 23 Part 655 Subpart F.
results and may be used.
5.2 Requirements in specifications referring to this test
7.5 Measurement Angles—This method uses the CIE goni-
method are for the chromaticity of the material as viewed at
ometer system (α, β , β , ε). The angles used in the measure-
1 2
night. These requirements are generally stated using four or
ment are: observation angle α = 20 min of arc (0.33°), entrance
five corner points that form a box that limits the range of
angle β = 5°, entrance angle β = 0°, and rotation angles ε of
1 2
acceptable chromaticity. Most of these specifications are cat-
0° and 90°.
egoricalinnature;theydescribeasmallrangeofcolorsthatare
recognizable from a color naming or coding purpose
8. Calibration and Standardization
5.3 The method for compliance with the specification is to 8.1 Calibration of these instruments is to be performed
plot the measured (x, y) values and determine if the measured relative to a known spectral or tristimulus standard from a
point falls within the specification box for the color of interest. reliable source.
E3165−18
8.2 Calibration of Tristimulus Detectors—The instrument is 10. Procedure
adjusted to read the reference standard chromaticity values.
10.1 This method allows two procedures for determining
This may be done by calibration to a specific color or by
the chromaticity coordinates of the test specimen: the tristimu-
verification using multiple colors ensuring that the readings are
lus method and the spectral method. These methods are
consistent with the values on the standard.
described in Practice E811.
8.3 C
...