Abstract

In this report the results of an evaluation of the technical performance of the Dutch National Air Quality Monitoring Network in 1990 are presented. The average brute component efficiences, i.e. a measure for the availability of measuring data, are: - for the automatically measured components [CO, NOx, O3, SO2] 97% ; - for the meteorological parameters [global radiation, temperature, wind direction, wind speed] 96% ; - for aerosols etc. [black smoke, acidifying compounds, metals, tsp.] 97% ; - for the chemical composition of precipitation [i.a. acidifying compounds, heavy metals] 95%. Current Dutch legislation requires the measurement of a number of components in such way that only a minimal loss of data is tolerated. The number of stations which did not meet the legal requirements in 1990 are: 3 for CO [12% of the total number of stations], 2 for NO2 [5%], 11 for SO2 [13%], O for lead aerosol and 6 for black smoke [30%]. In general, considerable improvement has been achieved in comparison to 1989. Nevertheless, for certain activities [black smoke and chemical composition of precipitation logistical procedures have to be redefined to improve efficiency and/or quality of the measurements.