Standard Test Method for Evaluation of Visual Color Difference With a Gray Scale (Withdrawn 2012)

SIGNIFICANCE AND USE
The total perceived color difference between two non-self luminous specimens is compared as an equivalent lightness difference between two neutral gray specimens on a gray scale. A fundamental assumption is made that the total color difference can be so evaluated in terms of an equivalent lightness difference. Only the total color differences, that is, a summation of the differences in hue, lightness, and chroma between two specimens is evaluated; this test method is not applicable to the separate precise evaluation of the hue, lightness, and chroma components of color difference.
The total color difference determined by this test method depends on the degree of uniformity of the specimens and on the sharpness of the dividing line between them. The color difference between specimens having rough or mottled surfaces appears smaller than it would if the specimens had smooth and uniform surfaces. Thus the equivalent CIELAB lightness difference determined for non-uniform specimens will be smaller than for uniform specimens. Likewise, specimens whose dividing line is not sharp will appear to have smaller color differences than those with sharp dividing lines, and for this reason, the equivalent visually observed CIELAB lightness differences will be smaller than the color differences obtained from instrumental measurements.
5.2.1 A physically sharp border between colors differing slightly in the yellow-blue direction in color space appears diffuse. The perceived color difference is noticeably increased by a hairline black separation. This technique imposes a more rigorous test of such small differences.
In the CIELAB system, a unit of color difference is intended to represent the same visual difference in each of the three attributes; lightness, hue and chroma or alternatively lightness, redness-greeness, yellowness-blueness. It is valid to express color differences that are not simply lightness differences by comparison to a lightness-difference scale.
Personnel ...
SCOPE
1.1 This test method describes a painted gray scale and the procedure to be used in the visual evaluation of color differences of non-self luminous materials by comparison to this scale.
1.2 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.
WITHDRAWN RATIONALE
This test method describes a painted gray scale and the procedure to be used in the visual evaluation of color differences of non-self luminous materials by comparison to this scale.
Formerly under the jurisdiction of Committee E12 on Color and Appearance, this test method was withdrawn in April 2012 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

Status
Historical
Publication Date
30-Nov-2003
Withdrawal Date
12-Apr-2012
Technical Committee
Drafting Committee
Current Stage
Ref Project

Relations

Buy Standard

Standard
ASTM D2616-96(2003) - Standard Test Method for Evaluation of Visual Color Difference With a Gray Scale (Withdrawn 2012)
English language
3 pages
sale 15% off
Preview
sale 15% off
Preview

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:D2616–96(Reapproved2003)
Standard Test Method for
Evaluation of Visual Color Difference With a Gray Scale
This standard is issued under the fixed designation D2616; 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.
INTRODUCTION
This test method was developed to provide a precise procedure for visually evaluating color
difference of non-self luminous specimens. It was patterned after a method standardized by the
American Association of Textile Chemists and Colorists (AATCC) designed to evaluate “change in
color” and this antecedent was reflected in the original title.
This test method provides for evaluation of small to moderate color differences (less than 15
CIELAB (International Commission on Illumination) color difference units) by comparing test
specimens to a series of paired gray color chips having progressively larger lightness differences.
Color difference is rated according to which of nine gray pairs of differences is visually closest to the
test pair, or by interpolation between gray-pair differences.
The gray-scale pairs are specified in terms of decimal differences in CIELAB color space. This
change together with two continuous, decimal numerical scale equations modeling the original scale
comprisethemajordifferencesbetweenthepreviouseditionandthisrevision.Thechangesweremade
to provide an ASTM test method that parallels closely the AATCC method.
1. Scope D1729 Practice for Visual Appraisal of Colors and Color
Differences of Diffusely-Illuminated Opaque Materials
1.1 This test method describes a painted gray scale and the
E1499 Guide for Selection, Evaluation, and Training of
procedure to be used in the visual evaluation of color differ-
Observers
ences of non-self luminous materials by comparison to this
2.2 AATCC Procedures:
scale.
AATCC Evaluation Procedure 1, Gray Scale for Color
1.2 This standard does not purport to address all of the
Change
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Definitions:
bility of regulatory limitations prior to use.
3.1.1 Definitions of appearance terms in Terminology E284
2. Referenced Documents are applicable to this test method.
2.1 ASTM Standards:
4. Summary of Test Method
E284 Terminology of Appearance
4.1 The gray scale consists of nine pairs of neutral gray
color standards of which Reference Pair 5 is two examples of
This test method is under the jurisdiction of ASTM Committee E12 on Color
thesamegray.Oneelementcommontoeachpairisthegrayof
and Appearance and is the direct responsibility of Subcommittee E12.11 on Visual
Reference Pair 5; the other element, being progressively
Methods.
lighter, provides a succession of lightness differences. Total
Current edition approved Dec. 1, 2003. Published December 2003. Originally
approved in 1967. Last previous edition approved in 1996 as D2616–96. DOI:
color differences between non-self luminous specimens are
10.1520/D2616-96R03.
expressed as either fractional, linear scale value between 1 and
Technical Manual of the American Association of Textile Chemists and
5 or as equivalent CIELAB color differences (DE* )by
Colorists, P.O. Box 12215, Research Triangle Park, NC 27709, Vol 68, 1993, pp. ab
348–349. comparisonwiththepaireddifferencesofthegrayscale,which
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
are predominantly lightness differences.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2616–96 (2003)
NOTE 1—The gray specimen common to each pair is specified to have TABLE 1 Gray Scale Characteristics
CIE 1976 metric lightness, L*=41.2(+0.6,−0.0).
CIELAB (DE*)
AATCC Step
Designations
Color Difference Tolerance(6)
5. Significance and Use
5.0 0.0 0.2
5.1 The total perceived color difference between two non-
4.5 0.8 0.2
selfluminousspecimensiscomparedasanequivalentlightness
4.0 1.7 0.3
3.5 2.5 0.3
differencebetweentwoneutralgrayspecimensonagrayscale.
3.0 3.4 0.4
A fundamental assumption is made that the total color differ-
2.5 4.8 0.5
ence can be so evaluated in terms of an equivalent lightness 2.0 6.8 0.6
1.5 9.6 0.7
difference.Onlythetotalcolordifferences,thatis,asummation
1.0 13.6 1.0
of the differences in hue, lightness, and chroma between two
specimensisevaluated;thistestmethodisnotapplicabletothe
separate precise evaluation of the hue, lightness, and chroma
7. Preparation of Specimens
components of color difference.
5.2 Thetotalcolordifferencedeterminedbythistestmethod 7.1 Specimens shall be uniform in color and gloss and shall
be free of scratches and other imperfections of surface texture.
depends on the degree of uniformity of the specimens and on
the sharpness of the dividing line between them. The color The specimen being compared to the standard should have the
same gloss and surface texture as the standard for maximum
difference between specimens having rough or mottled sur-
faces appears smaller than it would if the specimens had precision of color differences determination.
smooth and uniform surfaces. Thus the equivalent CIELAB
8. Procedure
lightness difference determined for non-uniform specimens
8.1 Illumination and Viewing:
will be smaller than for uniform specimens. Likewise, speci-
mens whose dividing line is not sharp will appear to have 8.1.1 Placethespecimensandthepairedgray-scalechartsin
the same plane on a horizontal surface with a neutral back-
smaller color differences than those with sharp dividing lines,
and for this reason, the equivalent visually observed CIELAB ground (middle gray to white) under the prescribed light
source. The light source shall be daylight or a daylight
lightness differences will be smaller than the color differences
obtained from instrumental measurements. simulator,forexampleacolor-matchinglightbooth.Makesure
that the specimen pairs whose color differences are to be
5.2.1 A physically sharp border between colors differing
slightly in the yellow-blue direction in color sp
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.