Download Manual: Mastersizer 2000 User Manual (MAN0384

MAN0384-1.0 Mastersizer 2000.book Page 6 Tuesday, March 20, 2007 8:56 AM
Chapter 6
Understanding the views
 Distribution – shows the type of distribution the analysis has used. Options
include change from volume to surface area, length or number. Remember
that the Mastersizer measurement is fundamentally a measurement of the volume distribution - transforming the result into a surface, length or number distribution is a mathematical process that may amplify any error in the original
result, especially at the fine end of the size distribution.
 Uniformity – a measure of the absolute deviation from the median.
∑
X i d ( x, 0.5 ) – d i
Uniformity = -----------------------------------------------d ( x, 0.5 ) X i
∑
Here d(x,0.5) is the median size of the distribution (where x is replaced by v, s,
l or n) and di and xi are respectively the mean diameter of, and result in, size
class i.
 Specific Surface Area (SSA) – the total area of the particles divided by the
total weight.
V
6 -----i
d
6
SSA = -----------------i = --------------------pD [ 3, 2 ]
p Vi
∑
∑
where Vi is the relative volume in class i with mean class diameter of di and p is
the particle density.
If the SSA is used, it is important that the density of the material is defined (on
the SOP Wizard’s Material dialogue). This figure is a mathematical calculation based on the assumption that the particles are both spherical and nonporous.
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