DISPOSITIVO PER LA MISURAZIONE DINAMICA DELLA DENSITA' DELLE PARTICELLE IN UNA CORRENTE GASSOSA

The invention relates to a device for measuring the density of particles in a flow of gas. The flow of gas flows through a measurement tube composed of an outer tube and an inner tube (1, 4), a dead-zone chamber (7) being defined between these two tubes and opening in the gas flow downstream of a measurement line (8). An annular body (13) encircling the measurement tube (5) contains optical windows (18, 19) associated with light guides (20, 21) connected to a light source and to an analysis unit. Inlets (22, 24) for sweeping (flushing, purging) air are provided in chambers (16, 17) arranged in front of the windows (18, 19). The sweeping air is supplied preferably by means of an air pump set to a constant mass flow rate, so as to guarantee precise measurement over a wide range of parameters. Field of application: measurement of the opacity of gases.