PR-680/680L User Manual
8
FIGURE 53 - L*U*V* SETUP SCREEN
Touch
Delta E Disabled
to
enable
color difference measurements if desired. If
Delta E
is enabled,
Select
under the
Reference
column bec
omes activated. The Reference is the “Golden Sample” against which
all subsequent samples are compared for color difference calculations. Delta E (CIE
E*ab or
E*uv)
calculates color difference in the respective color systems using the following equations:
(
) (
) (
)
2
2
2
*
*
*
*
b
a
L
ab
E
+
+
=
(
) (
) (
)
2
2
2
*
*
*
*
v
u
L
uv
E
+
+
=
EQUATION 3 -
E*AB
EQUATION 4 -
E*UV
7.
To make a
Reference
or
Source
measurement:
In most cases, a
Source
or
Reference
measurement is a
Luminance
measurement. Therefore,
the instrument should be set up to perform this type of measurement.
In the case of a
Source
measurement, a diffuse reflectance standard, such as the Photo Research
RS-3 or SRS-3, is placed in the exact location of the measurement area of the device under test
–
for example the face of a display. For making measurements of test samples, the reflectance
standard is replaced by the device under test without disturbing or changing the position of the
measurement instrument (PR-680/680L or PR-680/680L) or the light source.
a.
Touch
Select
under the
Reference
or
Source
column. The following screen appears:
b.
Make sure
Internal RAM
is selected in the
Current View
field.
c.
Press the
MEASURE button
on the top of the instrument.