Calibration System for Dust Sampling.
Final rept. 1 Oct 73-30 Sep 75,
CINCINNATI UNIV OHIO DEPT OF ENVIRONMENTAL HEALTH
Pagination or Media Count:
An aerosol chamber was designed, constructed and tested with each of three aerosol generators. A Nebulizer was provided for liquid aerosols, a Wright Dust Feed for long-term dust generation, and a Fluidizing Generator for short duration, high concentration dust aerosols. Uniformity of distribution of aerosol was tested with each of the three aerosol generating systems. Samples from side and top ports yielded a maximum coefficient of variation of 7 with typical values of 2. Samples from top ports averaged 95 of those from the side ports. Utility of the chamber for field testing was demonstrated by showing that the performance of Aerotec 34 cyclones and Unico 240 cyclones, operated at their rated flows, varied significantly. Size distributions, determined by an Andersen Sampler, were found to be approximately log-normal with the exception of the Nebulizer aerosol. The mass median diameter aerodynamic diameter was slightly greater in the lower portion of the chamber, confirming the settling of coarser dust suggested by the total mass concentrations from side ports being less than those from top ports. Some deficiencies in ease of sampling resulted in an improved chamber design. This report includes a complete description and detailed operating instructions as well as data and test results. Author
- Test Facilities, Equipment and Methods