# Sizing methods- phm140

The flashcards below were created by user Anonymous on FreezingBlue Flashcards.

1. Sieve
• 38-1000 mcm
• ED: sieve pore diameter (varies with particle shape, especially elongated shape)
• Average diameter: weight average diameter
• Function: pass particals through sieves
2. Optical Microscope
• 1-1000 mcm
• ED: dp (projected perimeter diamter) or da(projected area diameter)

AD: Number average diamter and weight average diameter (dn, dw)

Function: look at particles through microscope and measure them
3. Electron Microscope
0.01-1000 mcm

ED: dp (projected perimeter diamter) or da(projected area diameter)

AD: Number average diamter and weight average diameter (dn, dw)

Function: look at particles through microscope and measure them
4. Gravitational Sedimentation method and centrifugal method
• Gravitational sedimentation 10-1000 mcm
• Centrifugal 0.1-1000 mcm

• ED: stokes diamater= dstĀ
• AD: weight average diameter= dw

sedimentation methods:measure how quickly particle sediments, as this is proportional to particle size

note that the centrifugal method is the equation with angular velocity and the natural logarithm (w, and ln)
5. Laser light diffraction
• 1-1000 mcm
• analyzes dry or wet samples by shining a light on them and measuring diffraction, the larger the particle the narrower the angle of scattering and the higher the intensity

• ED: area diameter, darea
• AD: volume/weight/number average diameter= dv, dw, da

all of the AD are calculated from the ED
6. Dynamic laser light scattering
• 0.01- 2 mcm
• ED: area diamater, darea
• AD: dw, dv, dn (weight volume number)

Function: measures scattering using the principal of Brownian motion of small particles (smaller or comparable to laser light)

Use Stoke-einstein equation , find it as D=kT*10^7/ (3*pi*viscosity*dh)

note that dn is the hydrodynamic diameter
7. Coulter Counter
• 0.1-1000 mcm
• usually requires insoluble particles

• ED: volume diameter (regardless of shape-only one that doesn't assume spherical particles)
• AD: volume average diameter, dv

look at tutorial 6 for more detailed explanation