FINE PARTICLE DETECTOR

摘要

PURPOSE:To detect fine particles in an aerosol stably with high precision by arranging a detection cell through which the aerosol to be measured is passed in an external resonator which resonates with the output of a laser oscillator, and measuring scattered light. CONSTITUTION:The laser output light 6 from the laser oscillator 1 is made incident on the Fabry-Perot optical resonator constituted by placing mirrors 2 and 2' opposite to each other. Laser light 8 is reflected repeatedly between mirrors 2 and 2' to obtain a value nearly equal to the light intensity in the laser resonator. The aerosol 7 to be measured is passed through a detection cell 3 in the resonator from a suction nozzle 4 while crossing the laser luminous flux and discharged through a discharge nozzle 5. Laser light scattered by fine particles in the aerosol is converged through a condenser lens optical system 9 and converted into an electric signal by a photodetector 10.