HunterLab EasyMatch QC, Руководство пользователя

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EasyMatch QC User’s Manual Version 2.1
A-30 Measurement Values
Note: Only the ColorQuest XE, LabScan XE, UltraScan XE, UltraScan PRO, and UltraScan VIS
instruments with the UV control option installed may correctly calculate Ganz Whiteness.
Information from Griesser, Rolf, “Assessment of Whiteness and Tint of Fluorescent Substrates with
Good Interinstrument Correlation,”
Color Research and Application , Vol. 19, 1994.
WI GANZ Difference is also available, and is defined as follows:
dWI GANZ = (WI GANZ)
sample
- (WI GANZ)
standard.
Y Brightness
Y brightness is the Y value from the CIE XYZ color scale.
Y Brightness Difference is also available, and is defined as follows:
dY Brightness = (Y Brightness)
sample
- (Y Brightness)
standard.
Yellowness Indices
Visually, yellowness is associated with scorching, soiling, and general product degradation by light,
chemical exposure, and processing. Yellowness indices are used chiefly to measure these types of
degradation.
Yellowness Index per ASTM Method E313 is calculated as follows:
( )
Y
Z C - X C 100
= E313 YI
Z x
where X, Y, and Z are the CIE Tristimulus values and the coefficients depend on the illuminant and
observer as indicated in the table below. Yellowness Index may only be calculated for illuminants D65
and C. A blank cell is received when any other illuminant is in use.