Ground based in situ observations of filter_3pack at Keldsnor (DK0005R). These measurements are gathered as a part of the following projects CAMP, EMEP and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: aluminium in aerosol (mass_concentration_of_aluminium_in_dry_aerosol_particles_in _air), arsenic in aerosol (mass_concentration_of_arsenic_in_dry_aerosol_particles_in _air), calcium in aerosol (mass_concentration_of_calcium_in_dry_aerosol_particles_in _air), chromium in aerosol (mass_concentration_of_chromium_in_dry_aerosol_particles_in _air), copper in aerosol (mass_concentration_of_copper_in_dry_aerosol_particles_in _air), iron in aerosol (mass_concentration_of_iron_in_dry_aerosol_particles_in _air), lead in aerosol (mass_concentration_of_lead_in_dry_aerosol_particles_in _air), manganese in aerosol (mass_concentration_of_manganese_in_dry_aerosol_particles_in _air), nickel in aerosol (mass_concentration_of_nickel_in_dry_aerosol_particles_in _air), potassium in aerosol (mass_concentration_of_potassium_in_dry_aerosol_particles_in _air), selenium in aerosol (mass_concentration_of_selenium_in_dry_aerosol_particles_in _air), sulphate_total in aerosol (mass_concentration_of_total_sulphateexpressed_as_sulphur_in_dry_aerosol_particles_in_air), sum_nitric_acid_and_nitrate in air+aerosol (mass_concentration_of_sum_nitric_acid_and_nitrate_expressed_as_nitrogen_in_aerosol), zinc in aerosol (mass_concentration_of_zinc_in_dry_aerosol_particles_in _air)