Particle characterization is an important component in product research and development, manufacturing, and quality control of particulate materials. In this study a laser-based phase Doppler particle analyzer (PDPA) was used to measure particle size and velocity. Two different particles including humid particles and fog particles were tested using the PDPA. Several tests were conducted under different conditions and all data were analyzed using the statistical method and analysis of variance (ANOVA) to see which factor affects particle performance. The humid particle flow rate has a significant effect on both the particle mean diameter and the particle mean velocity with 90% confidence. The type of oil particles has a significant effect on the particle mean velocity with 90% confidence.