Ground based in situ observations of low_vol_sampler at Virolahti II (FI0017R). These measurements are gathered as a part of the following projects EMEP, CAMPAIGN and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: ammonium in pm1 (mass_concentration_of_ammonium_in_pm1_in_air), ammonium in pm10 (mass_concentration_of_ammonium_in_pm10_in_air), ammonium in pm25 (mass_concentration_of_ammonium_in_pm2p5_in_air), calcium in pm1 (mass_concentration_of_calcium_in_pm1_in_air), calcium in pm10 (mass_concentration_of_calcium_in_pm10_in_air), calcium in pm25 (mass_concentration_of_calcium_in_pm2p5_in_air), chloride in pm1 (mass_concentration_of_chloride_in_pm1_in_air), chloride in pm10 (mass_concentration_of_chloride_in_pm10_in_air), chloride in pm25 (mass_concentration_of_chloride_in_pm2p5_in_air), magnesium in pm1 (mass_concentration_of_magnesium_in_pm1_in_air), magnesium in pm10 (mass_concentration_of_magnesium_in_pm10_in_air), magnesium in pm25 (mass_concentration_of_magnesium_in_pm2p5_in_air), nitrate in pm1 (mass_concentration_of_nitrate_in_pm1_in_air), nitrate in pm10 (mass_concentration_of_nitrate_in_pm10_in_air), nitrate in pm25 (mass_concentration_of_nitrate_in_pm2p5_in_air), pm10_mass in pm10 (mass_concentration_of_pm10_ambient_aerosol_particles_in_air), pm1_mass in pm1 (mass_concentration_of_pm1_ambient_aerosol_particles_in_air), pm25_mass in pm25 (mass_concentration_of_pm2p5_ambient_aerosol_particles_in_air), potassium in pm1 (mass_concentration_of_potassium_in_pm1_in_air), potassium in pm10 (mass_concentration_of_potassium_in_pm10_in_air), potassium in pm25 (mass_concentration_of_potassium_in_pm2p5_in_air), sodium in pm1 (mass_concentration_of_sodium_in_pm1_in_air), sodium in pm10 (mass_concentration_of_sodium_in_pm10_in_air), sodium in pm25 (mass_concentration_of_sodium_in_pm2p5_in_air), sulphate_total in pm1, sulphate_total in pm10 (mass_concentration_of_sulphate_total_in_pm10_in_air), sulphate_total in pm25 (mass_concentration_of_sulphate_total_in_pm2p5_in_air)