Jadak Photo Research SpectraScan PR-7 Series, User Manual

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Chapter 5
– Setup Menu
50
FIGURE 43 - 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 becomes 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 formulas:
( ) ( ) ( )
2 2 2
* * * * b a L ab E
 +  +  = 
( ) ( ) ( )
2 2 2
* * * * v u L uv E
 +  +  = 
EQUATION 3 -
ΔE*AB
EQUATION 4 -
ΔE*UV
7.
To make a Reference or Source measurement:
If measuring an illuminated sample, the user will need to have a Reference and Source measurement
selected. The Source measurement will need to be supplied first. If measuring a self-luminous sample,
only the Reference measurement is necessary.
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.
To make a Reference measurement, measure the device under test. If a Source measurement was
made first, replace the reflectance standard with the sample in the exact same location.
a. Touch Select under the Reference or Source column. The following screen appears: