ALTANA Micro-Haze Plus - Manual (Page 38)

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Measuring Principles 10
When light is reflected on systems
containing pigments, such as
paints, varnishes or plastics, a part
of the illuminated light penetrates
into the material and is scattered
diffusely at the pigments. The
measuring unit comprises an addi-
tional detector to compensate for
this scattered light which is not
caused by the surface (brightness
compensation).
In order to take into consideration
the human perception of haze the
haze values normally are indicated
logarithmically. The logarithmic
haze value is calculated from the li-
near intensity of the scattered light
according to the following formula:
H = K·lg ( + 1)
The constant (K=1285.1) has been
calculated such that a logarithmic
value of 1 000 is obtained for a li-
near haze of 100. Two different
displays can be selected to display
the measured values:
Hlog – logarithmic scaling with
brightness compensation
Hlin – linear scaling without
brightness compensation
The setting Hlin, however, is only
used in very specific applications
(highly scattering surfaces without
pigments).
The calibration data always relates
to the linear haze value without
brightness compensation.
Hlin
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