More on Centrifuges...

Sedimentation/centrifugation provides high resolution and accuracy over a wide size range from nanometers to microns. It is based on the fractionation of particles according to Stokes’ Law, and particle density is the only special information required. Measurement times are typically in the range of five to thirty minutes, depending upon the breadth of the distribution.

A rock in a pond :

• Larger rocks fall faster, smaller rocks fall slower
  
• From measured time t, the size d can be calculated using Stokes' Law

• Larger sizes can be measured under normal gravity conditions
  
• Centrifugation greatly extends the range at the smaller end
  
• Scanning the head further increases speed of measurement
  
• Very high resolution because of fractionation by size
  

Choose the BI-XDC for inorganic particles including ceramics, clays, refractories, ores and metal powders, in fact any x-ray absorbing material with diameters in the range of 10 nm to about 100 microns. Direct mass response makes optical corrections unnecessary.

Choose the BI-DCP for the highest resolution size analysis on any type of particle from several nanometers to tens of microns in diameter which is, or can be, dispersed in a liquid. Exact light scattering corrections are used to ensure accurate results.