Method for dynamical detecting the concentration and size of nano-particles in gases

摘要

Dynamically detecting the size and number of nanometric particles in a gas comprises electrically charging the particles in a unipolar manner; passing a gas containing the particles through one or more electrically insulated porous body; and measuring the electric current produced on the porous bodies by diffusion of the nanometric particles onto the walls of the porous bodies. Preferred Features: A filter is arranged on the porous bodies to collect any remaining particles. The amount of collected particles is calculated by measuring the electrical current on the filter. The gas stream containing the particles are divided into two identical partial streams. The particles are photoelectrically charged in the first partial stream and electrically unipolar charged in the second partial stream. The quotient of the electrical currents is formed on the corresponding porous bodies and/or filters.