Using a Laser Particle Counter to Enhance Sedimentology Laboratory Exercises

Abstract

Traditional size determination of fine-grained sediments by the pipette or hydrometer methods is tedious, very time consuming, and frequently not accurate. Using a laser particle counter is more accurate and the method can be used to quickly and accurately determine the size distribution of the less than 100μm fraction of very small samples. This paper describes the operation of the Spectrex Laser Particle Counter and its use in sedimentology laboratory exercises. In addition to doing size analysis of bottom sediments, the laser particle counter can be used to determine size distributions of suspended particles in saline water. It is not necessary to disaggregate or slake the flocculated particles prior to analyses. In the settling scan mode the laser counter can monitor particles in suspension at preset times and determine the settling rates of the sediment. The results are printed out in both tabular and graphical form.