StationsClassification
If concentrations of atmospheric components(immissions) exceed certain levels, it is a risk to human health. To reduce risk the emissions need to be reduced and the efficiency should be monitored in real-time.As contagious atmospheric gases and other components are emitted from various sources, it is necessary to know the most effective way to reduce the emissions.
The objective of this study is to determine the effect of different emission sources on local immissions in urban environment from immission-measurements at fixed sampling stations.
#General background:
Local immissions are measured in the European Union at sampling stations by law.
Emissions are reported from power-plants,industry and other sources. Traffic-emissions are estimated using average emission parameters (Handbook for Emission Factors for Road Transport;HBEFA) in combination with quantity of fuel sold and mileage estimates.
The distribution of the emissions - immissions - are calculated from emissions using computer simulations. The results of the simulations are concentration values (immissions) per volume element. These are generally no real-time data.
The accuracy of simulations is limited by the availability and quality of input data, which are to a large extend average values. Computing-power or computing-time determines the minimum size of the volume elements.The calculation of the dependence on time of day is an even more expensive.
Hence immissions need to be measured at points of interest. Local immissions are measured in the European Union at sampling stations by law (EU RICHTLINIE 2008/50/EG).
This study is limited to the analysis of the effect of Nitrogendioxide ($NO_2$) emissions on $NO_2$-immissions.
Real-time
For these measurements a standard EN 14211 is defined. The method is sensitive to detect low concentrations,however the quantum efficiency is low requiring amplification and careful calibration, to assure the required measurement quality of better than 15%.