The FEEA houses a Coulter LS230 which measures particle size distributions in granular natural and synthetic samples by laser diffraction. This equipment is heavily used in support of a range of projects in oceanography, geomorphology and sedimentology.
Laser particle size analysis is based on the principle that particles scatter and diffract light at certain angles based on their size, shape, and optical properties. A 750 nm diode laser is used for analysis in the size range from 400 nm to 2 mm. The beam passes through filters as well as projection and Fourier lenses and is spatially recorded onto 126 photodiode detectors. The particle size, shape, and optical properties of the particles control the spatial variation of the diffracted beam.
The advantages of this technique include ease of operation, large range of detectable particle sizes, and accuracy in the micron and submicron range.