Full Description
This document specifies a process for the electrical diffusion charging of aerosols with subsequentmeasurement of particle charge. With the aid of this method, it is possible to determine the lungdepositedsurface area (LDSA) concentration of particles in ambient air. Depending on the design of theelectrical diffusion charger, the LDSA of particles in the size range of approximately 20 nm toapproximately 300 nm is measurable.
Furthermore, this document specifies design criteria for LDSA measuring aerosol monitors as well asperformance criteria and the associated test procedures. The performance criteria depend on theapplication and they are more stringent when the instrument is operated in an air quality monitoringstation.
In the determination of the LDSA concentration, the share of geometric particle surface areaconcentration is determined that can be deposited in the alveolar region of the human lung. Typicalparticle surface area concentrations with alveolar deposition measured in urban areas range from5 μm
2/cm
3 to 50 μm
2/cm
3.
Instruments based on this measurement principle can be designed to be very compact with a low powerconsumption. This makes them ideally suited for hand-held measurements, other forms of mobileapplication or to measure personal exposure. On the other hand, they can be easily adapted to serve as a stationary instrument in air quality monitoring stations.