Variable Sample Illumination (Vsi); Translucent Sample Measurement - HunterLab LabScan XE Supplemental Manual

Variable Sample Illumination (VSI)

Each LabScan XE can measure in large area of view or 44 mm (1.75 in illuminated) and
50 mm (2 in) measured. If your instrument has VSI, then it can also measure as follows:
o
25 mm (1.0 in) illumination; 30 mm (1.2 in) measured
o
13 mm (0.5 in) illumination; 17 mm (0.7 in) measured
o
6 mm (0.25 in) illumination; 10 mm (0.4 in) measured
o
3 mm (0.13 in) illumination; 5 mm (0.2 in) measured
To use VSI, it is important to select the port size in use and standardize with the lens zoom
and the correct port plate in view. This can be saved as a mode.

Translucent Sample Measurement

All diffusely reflecting objects scatter light internally, but with translucent objects the
scattering points are far apart allowing incident light to travel a long distance before it
reemerges. This can make a translucent object appear to glow when illuminated at one
spot. Orange juice, milk and plastics are examples of translucent materials.
Normally a translucent object is seen entirely illuminated, and the viewer tends to
concentrate on a portion of the surface away from the edges to form a judgement of color.
To have the instrument reading correlate well with visual, the open port area should extend
well beyond the area of view. Using a smaller area of view from the port size allows the
externally scattered light to leave the sample and become part of the measurement.
When standardizing for translucent measurements, insert the port plate needed and select
the illumination as a mode.
LabScan XE Supplemental Manual for EasyMatch QC
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