The Process Aerosol Monitor PAM 510 determines in realtime the average particle size and number concentration in high-concentration, monodisperse aerosols. The SLG 250/270 Condensation Aerosol Generators from Topas produce such monodisperse aerosols in the size range from 0.2 to 8µm. Both particle size and particle concentration to be generated can be quickly adjusted. The Process Aerosol Monitor PAM 510 was developed for realtime measurement of the parameters mean particle size and particle number concentration. The instrument can directly be connected to the outlet of the aerosol generator series SLG. The system is well suitable for instrument calibration and aerosol research.