Sizing methods- phm140

• 38-1000 mcm
• ED: sieve pore diameter (varies with particle shape, especially elongated shape)
• Average diameter: weight average diameter
• Function: pass particals through sieves

• 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

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

• Gravitational sedimentation 10-1000 mcm
• Centrifugal 0.1-1000 mcm

• ED: stokes diamater= dst 
• 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)

• 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

• 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

• 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

• <10mcm
• for analyzing aerosols or drug powders
• ED: aerodynamic diameter= da

Can determine MMAD and GSD (mean mass aerodynamic diameter, geometric standard deviation)