HunterLab SpectraTrend HT, User Manual

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SpectraTrend HT User’s Guide 3.2
101
The ASTM D1925 method was withdrawn in 1995, but this formula still provides useful information. This
index is only displayed when the data view is configured for C/2°, as this is the only relevant
illuminant/observer combination.
Paper Brightness (Z%)
Paper brightness, Z%, is used in the evaluation of the degradation of white materials. It can also be a
measure of the effectiveness of bleaching.
Z% =
100Z
Z
CIE
n
.
Difference Indices (available when Display Type is Difference;
Reading of Both Standard and Sample Required)
D457B
This index yields the difference between the sample and the standard via the 457-nm Brightness index.
D457B = 457B
sample
- 457B
standard
.
dTint
This index yields the difference between the sample and the standard via the Tint indices.
dTint = Tint
sample
- Tint
standard
dWIE
This index yields the difference between the sample and the standard via the Whiteness Index.
dWIE = WIE
sample
- WIE
standard
dY Brightness
This index yields the difference between the sample and the standard via the Y brightness index.
dY = Y
sample
- Y
standard
.