Microscopic Measurement of Particle Size

1
Microscopic Measurement of Particle Size
Reading Chap 20
Q How do you determine this particles size?

• Equivalent sizes of Irregular Particles (2-d)
• Martins diameter
• Ferets diameter
• Projected area diameter

Q Orientation?
2
Porton Graticule (printed on eye piece)
Calibration
Stage Micrometer (calibration standard printed on
glass slide) distance between the smallest lines
is 10 mm.
A-F is 200 times of d0.
3
Degussa P25 TiO2 particles TI 1243
4
Turbulence Borders of clouds and smoke
plumes Geometry of lung airways
5
Fractal Dimension
Self-similarity at different levels of
magnification
L total length ? step size Df fractal dimension
Q Df 1? 2? 3?
For agglomerates,
Npp Number of primary particles Rg radius of
gyration dpp diameter of primary particles
6
http//en.wikipedia.org/wiki/Diffusion-limited_agg
regation
Animation1
Animation2
Agglomerates formed by different mechanisms Q
How to change from compact-solid to fluffy?
Smoke, Dust and Haze, Friedlander, 2000
7
Reflection