Dry‐Powder Aerosol Dispersing Device with Long‐Time Output Stability

Operating parameters and performance characteristics are described for a dry‐powder Fe2O3 aerosol disperser used for periods up to 23 h with minimal operator attention. Aerosol mass concentration fluctuations in a 3 m3 dynamic‐flow chamber were determined over 23‐h periods for the aerosol generator with and without electronic feedback circuits. From the data presented in this paper and from observations made during 2 weeks of continuous operation, this ``rust duster'' was found to be capable of continuously dispersing Fe2O3 powder into 1.5 m3 of air per minute to produce aerosols having median concentrations from about 0.7 to 3.0 mg m−3. Over most of this concentration range, with or without the feedback control circuit, the mass concentration of Fe2O3 aerosol was kept within the ±50% variability limit originally set as acceptable for chronic animal exposure conditions.