The criteria for determining the location of sampling points for the measurement of sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air shall be those listed in Annex VI. The minimum number of sampling points for fixed measurements of concentrations of each relevant pollutant shall be as laid down in Annex VII and they shall be installed in each zone or agglomeration within which measurement is required if fixed measurement is the sole source of data on concentrations within it.
