ALTANA Haze-Gard Plus Operating Instructions - Manual (Page 30)

9. Parameters Appearance of Transparent
Materials
When a parallel beam of light strikes
a transparent specimen, a number of
effects may result, depending on the
nature of the material:
s
smooth surface
Some of the incident light will be
reflected from surfaces, and some
will pass through the specimen
unaltered. The specimen will
appear glossy and crystal clear.
The intensity of the transmitted
light will be diminished by the
inherent absorbance of the
material, dyes or pigments.
s
scattering
Diffuse scattering will decrease an
object’s imaging quality. Particles
inside the material or structures on
its surface may act as "scatterers".
The more scatterers are present,
the greater the amount of scattered
light; the distribution of scattered
light in space is related to the
scatterers’ size distribution. The
scattering behavior of a specimen
will determine its appearance.
Two different components can
be clearly distinguished visually
(Fig. 1).
s
Wide-angle scattering diffuses
light uniformly in all directions, and
the light intensity per angle is
small. This reduces contrast and
results in a milky or cloudy
appearance. This effect is called
haze.
s
Narrow-angle scattering deflects
light in small angles, so that the
light intensity is concentrated
within this narrow angular range.