The formation and growth of soot particles in a coannular diffusion flame have been studied using a laser extinction technique for particle size measurement. Direct matrix technique has been used for reconstructing the property fields. Measurements have been obtained with propane as the fuel for various fuel flow rates. The results reveal that the maximum soot volume fraction is located just inside the flame surface. Results indicate that the particle formation region obeys the Burke-Schumann scaling for flow rate dependence, whereas substantial differences occur in the oxidation region. The soot size distribution which was obtained by using light extinction method has been compared with the result by thermophoretic sampling technique.
