Introduction; Device Description; Measuring Principle - ColorLite Rugged 2 Bedienungsanleitung

2

Introduction

The colour of an object depends not only on its surface,
but also of the incident light. The sensation „colour"
of an object is dependent also on the observer. To
determine a colour difference between two objects,
these must be considered simultaneously under
controlled lighting conditions.
2.1

Device description

The spectrophotometer Rugged 2 allows an objective
determination of the colour difference between a
colour sample and a given colour standard. The 45°/0°
measuring geometry - Measurement at 0°, circular
illumination at 45°.
The Rugged 2 is equipped with a high resolution,
high contrast O-LED display. The probe head also
implements a long-lasting and maintenance-free LED
light source. The measurement is trigged by pressing
the trigger button.
The true spectral scan provides excellent long-term
reproducibility. Up to 1000 colour samples, plus 300
colours with spectral remission data and 1000 colour
standards can be stored in the non-volatile
Rugged 2 memory. The data exchange with the optional
ColorDaTra software can be made using the integrated
USB interface, Bluetooth or via WLAN.
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2.2

Measuring principle

The spectrophotometer Rugged 2 implements the spectral
method, which is the most accurate method of measurement
colours. The sample is illuminated with a defined light
source and the remitted light from the surface is measured
spectrally. Since the surface colour depends on the
illumination, the reflected spectrum must be weighted with
a standardised source of light. The resulting spectrum is
then evaluated with the three spectra, which are based
on the red, green and blue sensitivity of the human visual
system, and we obtain the three values X, Y and Z. As with
the light source, the three sensory functions of the human
eye are standardised for a 2° and a 10° viewing angle. This
distinction is necessary since the colour sensation depends
on the observation angle.
The measured colour values must always specify the
standard illumination and observation angle used. Since
colours are subjective variables, it is useful to convert the
base colour values (tristimulus values) X, Y and Z in other
colour scales, which are based on colour perception. This
means the colour difference value ∆E is more similar to
the perceived difference (more information on the theory
of colour measurement on the delivery is CD). There are
a variety of colour systems in use, such as: Yxy, L*, a* b*
or L*u*v* The ∆E colour differences, i.e. the difference
between the two colours are calculated from the sum of the
differences of the three colour values for a particular colour
space.
ColorLite GmbH | Rugged 2
Introduction