Extending traceability in airborne particle size distribution measurements beyond 10 µm : Counting efficiency and unit-to-unit variability of four aerodynamic particle size spectrometers
The aim of this study was to establish traceable number concentration measurements of airborne particles beyond 10 μm in particle size. To this end, the primary standards for particle number concentration at the National Metrology Institutes of Switzerland and Japan were further developed to extend their measurement capabilities. Details on the upgraded setup are provided. An inter-comparison of t