HunterLab EasyMatch QC, Руководство пользователя

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EasyMatch QC User’s Manual Version 2.1
Measurement Values A-13
test specimen (great deal of staining). A value of 5 corresponds to virtually no staining, whereas 1
indicates poor color fastness.
ISO Grey Stain, as implemented in EasyMatch QC, is based on ISO 105-A04:1989, Textiles — Tests
for colour fastness — Part A04: Method for the instrumental assessment of the degree of staining of
adjacent fabrics. It is intended as an alternative to visual assessment as described in AATCC Evaluation
Procedure 2, “Gray Scale for Staining.”
The ISO Grey Stain result is based on the calculations below.
2 2
GS
* dL - * dE 0.4 - * dE dE
=
Use dE
GS
to calculate the SSR as follows:
ISO Grey Stain = 6.1 - 1.45 ln (dE
GS
) for Ratings 1 to 4.
If SSR calculated by the above equation is greater than 4, recalculate using the following equation:
ISO Grey Stain = 5 - 0.23dE
GS
for Ratings 4 to 5.
Metamerism Index
The Metamerism Index is designed to indicate the degree to which two samples which match under one
illuminant no longer match under a second illuminant. The metamerism index feature allows the
comparison of Hunter Lab values relative to operator-selectable illuminants. These values must be
calculated from spectral reflectance values. The formula for deriving the index is:
( ) ( ) ( )
2
n2 n1
2
n2 n1
2
n2 n1
db - db da - da dL - dL Index Metamerism
+ + =
where n1 is the 1st illuminant and n2 is the 2nd illuminant, and d = Value
sample
- Value
standard
.
The bottom half of each pair
shows the starting color of the
adjacent fabric. The top half
shows the color of the treated
adjacent fabric. (Illustration
from AATCC Evaluation
Procedure 2).