Intelligent laser diffraction instrumentation for particle size analysis

Particle and droplet size distributions, being parameters of fundamental importance, should be priority measurement objectives for intelligent sensors in next generation propulsion systems. Unfortunately there are a number of problematic scientific issues limiting the development of laser light scattering particle sizing instruments capable of autonomous, self-diagnosing operation in hostile environments. Beam steering due to thermal gradients, multiple scattering from high number density aerosols, and contamination of windows and electro-optical components have been and will continue to be potentially catastrophic problems. The research is concentrated in three areas: development of rapid and robust computational algorithms for the laser diffraction inverse scattering problem; synergism of electro-optical detection strategies with the inverse scattering algorithms; and techniques for on-line calibration and performance evaluation particularly with respect to the potential detection and correction for multiple scattering effects.