BYK haze-gard plus Mode D'emploi page 33

Notes:
measurement range is auto-
matically switched over to a
display with two decimal places.
mean is taken across the illumi na-
ted surface of the specimen. Since
it cannot be assumed that optical
characteristics will be uniform over
the entire surface of the specimen,
we recommend taking readings at
a variety of points on the speci-
men, and using the mean.
readings from dirty, scratched or
otherwise damaged areas of the
specimen, unless you want to
obtain the measurements as an
indication of the severity of such
damage, for example in
measuring abrasion resistance
(Taber Abraser).
plane-parallel as possible; a
wedge shape will deflect light.
All manuals and user guides at all-guides.com
readings note the specimen
thickness, since absorbance and
scattering increase in direct
proportion to thickness.
characteristics may affect
transparency measurements.
Particularly when specimens are
glossy on one side and dull on the
other, the same surface should
always be directed toward the
sphere aperture.
sphere inlet reflects light from the
specimen within the sphere. This
improves the sphere's efficiency,
and the measured total
transmittance will be slightly
higher.
For completely clear specimens,
you can obtain precise
transmittance values by keeping
the specimen at the clarity port
during the transmittance
measurement.
Specimens with high levels of
scatter should always be placed at
the haze port. Here we recommend
calibrating the instrument with a
previously measured transmittance
standard (see Section 5.3). This
standard must have a surface
reflectivity similar to that of the
specimens to be measured.
plane-parallel walls and an edge
length of at least 50 mm may be
used to take readings on liquids.
Appropriate cuvettes are listed in
the Ordering Guide.
know whether scattering is caused
by internal scatterers or surface
structure. In these cases, surface
scattering can be eliminated by
immersing the specimen during
the readings in a liquid with the
same refractive index as the
specimen. Only bulk scattering will
then come into play.