# Sizing methods- phm140

 Sieve 38-1000 mcmED: sieve pore diameter (varies with particle shape, especially elongated shape)Average diameter: weight average diameterFunction: pass particals through sieves Optical Microscope 1-1000 mcmED: 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 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 Gravitational Sedimentation method and centrifugal method Gravitational sedimentation 10-1000 mcmCentrifugal 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) Laser light diffraction 1-1000 mcmanalyzes 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, dareaAD: volume/weight/number average diameter= dv, dw, da all of the AD are calculated from the ED Dynamic laser light scattering 0.01- 2 mcmED: area diamater, dareaAD: 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 Coulter Counter 0.1-1000 mcmusually 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 Cascade inspectors <10mcmfor analyzing aerosols or drug powdersED: aerodynamic diameter= da Can determine MMAD and GSD (mean mass aerodynamic diameter, geometric standard deviation) AuthorAnonymous ID271238 Card SetSizing methods- phm140 DescriptionSizing methods -phm140 Updated2014-04-20T21:11:42Z Show Answers