1.505
1.510
1.515
1.520
1.525
1.530
1.535
1.540
1.545
1.550
1.555
1.560
1.565
1.570
1.575
1.580
1.585
1.590
1.595
1.600
90.0
90.8
91.6
92.4
93.2
94.1
94.9
95.7
96.5
97.3
98.1
98.9
99.7
100.5
101.3
102.1
102.8
103.6
104.4
105.2
9.00
9.08
9.17
9.25
9.33
9.41
9.49
9.57
9.65
9.73
9.81
9.89
9.97
10.05
10.13
10.21
10.29
10.37
10.45
10.52
Glass
Measurable gloss of a flat glass surface with optical polish
depends solely on the refractive index of that glass as
shown in the table below. Provisions such as making the
glass thicker, applying matte black coat and/or giving a
wedge-shaped cross-section become necessary when
measuring a transparent glass sample, in order to prevent
reflections off the back surface from interfering with the
measurements.
Ceramic tile
The figure below shows how light reflects off a ceramic tile.
Most light bounces off the surface as diffuse reflection and
specular reflection, and no light penetrates the surface.
Both diffuse reflection and specular reflection are
independent of light absorbing characteristic and therefore
the color of ceramic tiles has almost no effect on
measurements. A ceramic tile retains a stable and uniform
surface condition. It is often used as the secondary
standard for this reason, covering midrange glossiness not
well represented by the primary standard made of glass.
Incident light
Specular reflection
Diffuse reflection
Ceramic tile
Specular reflection angle 60
°
Glossiness
Reflection coefficient
Refractive index
Variations in reflection
due to different
surface conditions
Values displayed by the HORIBA Gloss
Checkers have strong correlation to
reflections at the sample surface.
The property of reflective light depends
on the structure and surface conditions
(grain, refractive index, etc).
It is important to understand surface
characteristics of various materials when
using HORIBA Gloss Checkers.
The following are some examples of
different materials and their properties.
Sample
Measurements
Gloss Checker
15
16
