Ground based in situ observations of pm25_mass at Auchencorth Moss (GB0048R) using TEOM. 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: pm25_mass in pm25_volatile (mass_concentration_of_pm25_mass_in_non_refractory_pm2p5_in_air), pm25_mass in pm25_non_volatile (mass_concentration_of_pm25_mass_in_refractory_pm2p5_in_air)