FEI Quanta FEG 250, User'S Operation Manual

Page: 206 / 228

System Options: Quanta Morphologi
9-58
FIGURE 9-49 FILTER MEMBRANE
IMAGE ACQUISITION
All analyzed particles must fill certain number of pixels in the image for
accurate size calculation. Therefore table of particle size classes that
fulfill the pixel number requirements was defined. Use of the size
classes for the image acquisition is recommended.
TABLE 9-4 SIZE CLASSES RECOMMENDED FOR PARTICLE
ANALYSIS
Images for the particle analysis must provide maximum contrast
between particles and the ITO slide. Contrast and brightness of any
applicable detector should be adjusted in this way. Videoscope (F3)
can be used for the best setting (see peaks of light spheres on dark
substrate in the following Fig).
Another tool that can be used for the verification of contrast/brightness
setting is the
Processing page / Enhanced image module / Color
tab. The coloring control area displays the active quad image
histogram and enables to create a color profile. Peaks for both the
substrate and particles are visible in the histogram when the contrast
between particles and substrate is set properly. Therefore, substrate
and particles can be easily distinguished and colorized.
Magnification
HFW
[µm]
Min. particle
size [µm]
Max. particle
size [µm]
300000 1 0.016 0.1
200000 1.5 0.023 0.15
150000 2 0.031 0.2
100000 3 0.047 0.3
75000 4 0.062 0.4
50000 6 0.094 0.6
30000 10 0.156 1
20000 15 0.234 1.5
10000 30 0.468 3
3000 100 1.558 10
1000 300 4.675 30
500 600 9.35 60
100 3000 46.751 300