The design of an instrument which measures particulate size and loading of the off gas from a fluidized-bed combustor is discussed. This noninvasive technique is based on the use of Fraunhofer diffraction. Experimental results are presented for three size fractions of synthetic diamond dust in water which approximates the refractive index of coal dust in air.
"Rapid Particle Size And Loading Measurements In Fluidized-Bed Combustors: An Instrument," Optical Engineering 19(5), 195777 (1 October 1980). https://doi.org/10.1117/12.7972603