A Comparative Study of Particle Size Distributions Obtained by Stokes and Optical Diameter Measurements,
AIR FORCE ROCKET PROPULSION LAB EDWARDS AFB CA
Pagination or Media Count:
Solid rocket motor performance is greatly influenced by the size of various solid ingredients such as that of the oxidizer or metal fuel. The particle size instrument of choice with the solid propellant industry in the past has been the Mine Safety Appliances Co. MSA particle size analyzer. The MSA measures equivalent stokes diameters by a combination of gravity and centrifugation. Unfortunately, this instrument is no longer commercially available, thus an urgent requirement exists in the solid propellant industry to find an alternative particle size instrument that will provide statistically similar results to the MSA. The HIAC Royco, PA-720, has been found by this laboratory to be a reliable particle size instrument. A direct comparison of the particle size distributions obtained by the MSA and the HIAC Royco instruments is presented. A microcomputer program was also developed for calculating various statistical means from the raw data of both instruments to aid in the representation of a particle size distribution. The data indicates that the HIAC Royco particle size distributions are more nearly log normal and more biased toward the coarse particles than the MSA data.