International Intercalibration and Intercomparison Measurements of Radon Progeny Particle Size Distribution
Abstract
Because there is no standard method for 222Rn progeny size measurements, verifying the performance of various measurement techniques is important. This report describes the results of an international intercomparison and calibration of 222Rn progeny size measurements involving low pressure impactors (MOUDI and Berner) and diffusion battery systems, as well as both alpha- and gamma-counting methods. The intercomparison was held at the Environmental Measurements Laboratory from June 12-15, 1995. By using various measurement techniques and methods with different data analysis procedures, this intercomparison study allowed for a rigorous evaluation of instrument performance. Five different well-controlled particle sizes (80, 90, 165, 395, and 1200 nm) of near monodisperse condensation Carnauba wax aerosol and two well-defined bimodal size spectra (160 and 365 nm, & 70 and 400 nm) were used. Twenty tests were completed, covering both low and high concentrations of 222Rn and test aerosols. For the single-mode test aerosol, the measurements were found to agree within the size range covered by the test aerosols. The best agreement was found between the two low pressure impactors. Some differences between the impactor technique and the diffusion battery method were observed in the specific peak locations and the resultant geometric mean diameters. For the two bimodal size distribution aerosols, the MOUDI measurements showed two modes, while the other three devices showed a single mode size distribution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1997
- Accession Number
- ADA352401
Entities
People
- Keng-wu Tu
Organizations
- United States Department of Energy