Bahram Keyvani - Department of Chemical and Biochemical Engineering. University College London, Torrington Place, London WC۱E ۷JE. England
Hassan Al-Khoory - Department of Chemical and Biochemical Engineering. University College London, Torrington Place, London WC۱E ۷JE. England
Haroun Mahgerefteh - Department of Chemical and Biochemical Engineering. University College London, Torrington Place, London WC۱E ۷JE. England

When a container partly filled with a powder is vibrated in the transverse direction with a maximum acceleration greater than that due to gravity the particles inside the container become effectively "fluidised". The amount of frictional interactions transmitted from the powder to the container as a result of the vibration is then a function of the average particle size and its distribution. This paper describes the design and development of a novel vibrating reed technique operating on the basis of the above principle for the measurement of average particle s ize. Typical resolution in size is between ۸۲۰ µm in the ۲۰-۹۰۰ µm size range particles Preliminary results are also reported which establish the potential of the device for use for particle size distribution analysis.