FINE PARTICLE COUNTER

摘要

This invention provides a fine particle counter that can measure fine particles, which float in a gas phase, are of nanometer size, and have a very low number concentration, under a wide range of pressure conditions from pressurized conditions to low pressure conditions, with high accuracy. An internal space in a mixing part (3) for contact mixing between saturated vapor of a high-boiling solvent generated in a saturator (2) constituting a condensation nucleus detector (1) and fine particles of nanometer size floating in an aerosol comprises a narrowest flow passage part of a circular shape in section located at the center part between the lower end face, into which a carrier gas is introduced, and the upper end face, through which the carrier gas is discharged, a truncated cone-shaped diameter reduction part in such a form that the sectional shape is circular and the diameter is gradually reduced from the lower end face side toward the narrowest flow passage part side, and a reversed truncated cone-shaped diameter increase part in such a form that the sectional shape is circular and the diameter is gradually increased from the narrowest flow passage part side toward the upper end face side. An aerosol introduction hole in communication with an aerosol introduction tube (8) is located in the narrowest flow passage part.