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Aerosol Concentration Standard Development
Two experimental systems have been developed to meet the requirements of providing an airborne concentration standard. A series of experiments were undertaken to demonstrate the feasibility of performing a concentration calibration of a typical widely available aerosol analyser (TSI Aerodynamic Particle Sizer (APS)). Well-defined test particles were generated form either a pneumatic medical nebuliser or a Computer Operated Monodisperse Aerosol Generator (COMAG). The airborne test particles were simultaneously sampled by the instrument under calibration and onto a filter to provide a reference airborne concentration. The measured data were analysed by several different methods and corresponding APS counting efficiencies were calculated. The results of each of these approaches are reported and compared. The sources of experimental uncertainties within each approach are highlighted, and the critical measurements are identified to ensure traceability in future use. The feasibility of adopting this approach to the calibration of aerosol analysers for concentration measurements has been clearly demonstrated.
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