FIELD: measurement.SUBSTANCE: invention relates to measuring particle concentration and mass concentration in an aerosol. Method comprises a sensor system for measuring particle concentration and mass concentration in an aerosol comprising an optical sensor for measuring a particle concentration and the particle size distribution, mechanical sensor for measuring a mass of collected particles and a controller adapted to monitor the particle concentration and the particle size distribution in the aerosol using the optical sensor, until detection of a particle generating event upon detection of a particle generating event corresponding to a specific combination of information on the particle concentration and the particle size range; mass measurement using a mechanical sensor when a particle generating event is detected and using the mass measurement to calibrate the optical sensor.EFFECT: technical result is the prolonged lifetime of the mechanical sensor and the increased accuracy of the perception of the mass
