Standards Development

Scope

This document specifies characteristics of a light scattering aerosol spectrometer (LSAS) which is used for measuring the size, number concentration and number/size distribution of particles suspended in a gas. The light scattering technique described in this document is based upon single particle measurements. The size range of particles measured by this method is between approximately 0,06 µm to 45 µm in diameter.

Instruments that conform to this document are used for the determination of the particle size distribution and particle number concentration at relatively high concentrations of up to 105 particles/cm3.

Application fields include:

— characterization of metered dose inhalers (MDI), dry powder inhalers (DPI) and nebulizers in pharmacy;

— production control of active agents;

— cut-off determination: impactors, cyclones and impingers;

— atmospheric aerosols: bio-aerosols, stables/composting facilities, nebulized droplets, measurements in street tunnels;

— fractional separation efficiency determination of filters.

For the above-mentioned applications, aerosol spectrometers should determine the particle size distribution and particle number concentration as accurately as necessary. For this purpose, they should have appropriate size resolution, sizing accuracy, counting efficiency and flowrate accuracy. These aerosol spectrometers are not suitable for the classification of clean rooms.