Malvern Instruments Spraytec, User Manual

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.
To change the format of the table shown in the window click the Columns
button. In the dialogue displayed use the pull-down lists to change the con-
tent of any column.
.
When all data are suitable click OK .
Problems with poor data
Two problems, beam steer and vignetting, may lead to erroneous size distribution
data. These can be fixed using the
Data handling options described in the
following section.
'
N o t e
. Do not remove detector data unless there is good reason – the accuracy
and resolution of the analysis will be reduced.
Vignetting
When measuring the particle size of sprays using laser diffraction, it is important
that the spray is close enough to the lens to allow the wide-angle scattered light
from small particles to be collected by the focussing lens. The maximum distance
between the spray and the lens that allows resolution of the smallest particle size
that can be measured defines the lens working range.
In this graphic:
+
is the focussing lens.
,
is the detector array.
.
is the focal length of the lens.
C H A P T E R 6
S p r a y t e c
P a g e 6 . 1 8
M A N 0 3 6 8
ILL
7452