HunterLab EasyMatch QC, User Manual

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EasyMatch QC User’s Manual Version 2.1
Measurement Values A-11
related to one of the standard pairs to yield the gray scale rating. On this scale, 5 indicates that next to
no color was lost, and 1 indicates that most color was lost.
ISO Grey Scale, as implemented in EasyMatch QC, is based on ISO 105-A02:1993, Textiles — Tests
for colour fastness — Part A02: Grey scale for assessing change in colour. It is intended as an
alternative to visual assessment as described in AATCC Evaluation Procedure 1, “Gray Scale for Color
Change.” It may be used in assessing any samples except those which have been treated with
fluorescent whitening agents.
The ISO Grey Scale result is based on the calculations below. Some terms were further explained
earlier in this chapter under “Opponent-Color Scales.”
2 2 2
* dHf + * dCf * dL = dEf
+
where
2
M
1000
10C + 1
dHk
= dHf






2
M
1000
20C + 1
dCk
= dCf






dHk = dH*
ab
- d
dCk = dC*
ab
- d
100
e C * dC
= d
x
M ab
−
The bottom half of each pair
shows the starting color. The
top half shows the color of
the treated fabric. (Illustration
from AATCC Evaluation
Procedure 1.)