AATCC EP9-2007 Visual Assessment of Color Difference of Textiles.pdf

AATCC Evaluation Procedure g
Visual Assessment of Color Difiference of Textiles
Developed in 1999 by AATCC Commit- or the determination and description of ASTM Standard D 1729-96 or evalua-
tee RA36: revised 2002
the magnitude of color difference of tex-tion environment, for both general and
Lile materials against a standard color crilical color difference determinations
opec
The recommendations contained in Table
Purpose and Scope
4. 2 When evaluating multicolored pal- I are more restrictive than this procedure
terns, each color is evaluated separately
but are within the limits described above
1. 1 This evaluation procedure provides
4.3 To determine if illuminant me
5.3 Viewing geometry
eneral principles and a procedure for de-tamerisi is present, evaluate specimens
5.3.1 Option A. The specimen plane
ermining and describing the color differ
nder more than one illu
and illumination source shall be parallel
ence of test specimens by visual compari-
4. 4 Only observers whose color vision to each other and aligned so that the light
son with a standard. The scope Is Lo has been tested normal using either the flux is incident at the center of the speck-
standardize the procedure for visual color Farnsworth Munsell 100 Hue Test (see men plane, which is set al a 35 +5o angle
difference evaluations of textile materi
10.1 )or the HVC Color Skills Test (see relative to the horizontal. The observer
als
10.2)for color acuity shall perform this shall view the specimens at a 90 angle
procedure.
2. Principle
relative to the plane of the specimens
This option shall not be used for evalua
2. I The color of a specimen or spec
5. Apparatus
tions of glossy or non-matte specimens
mens and a reference standard are com
5, 1 Illumination conditions, The sourc
The observer shall take care when evalu
pared and evaluated under specific light
under which the comparison is made aling specimens not to block the incident
ing and viewing conditions. The shall be determined prior to evaluation
light from the source
observed color difference can also be Sources simulating any of the followin
5.3.2 Option B. The illumination
compared with tolerance range speci-
mens
SNE illuminants may be utilized(see 10.3 Source is horizontal. The specimen plane
d10.4
shall be horizontal, resulting in illumin
Lion incident at a 90 angle relative to the
3. Terminology
Color
specimen plane. The observer shall view
lluminant Description Temperature
aLa45±5° angle relative to the speci
3. I chroma, n -the proportion of D
Daylight
6500K±200
men. This option shall be used for either
spectrally pure color that expresses the D,
Daylight
500K±200
malle specimens
degree of departure from the gray of the A
descent2856K±200
5.3.3 Option C. The illumination
same lightness Le. brighter or duller
Cool White
4230K±200
3.2 hue, n -the attribute of color per
Fluorescent
source is horizontal. The specimen plane
shall be at a45士5° angle to horizonta
ception by means of which an objec! 1s Note: Exceptions to these sources are ne-resulting in illumination incident al a 45
jud ged to be red, orange, yellow, green
gotiable by the contractual