CLASSIFYING SYSTEM AND FINE PARTICLE MEASURING DEVICE

摘要

A classifying system for retrieving a specified particle size range after being classified. In a preferable embodiment, an electric field for classifying charged fine particles according to electric mobility is generated by a center electrode (3) and an outside electrode (4). A sheath gas supply unit (7) is provided at the upper portion of a housing (1). An aerosol supply unit (11), having an introducing port (11a) on the outside electrode (4) side in a classifying region (5) and supplying charged aerosol at a constant flow rate from the introducing port (11a), is provided. A large-particle-size-side discharge unit (13), having a discharge port (13a) on the outside electrode (4) side and discharging that part of charged fine particles in classified charged aerosol that has at least a specified particle size at a constant flow rate along with part of sheath gas, is provided on the downstream side in a sheath gas flow in the classifying region (5). A detector (18) for detecting as an electric quantity the remaining number of charged fine particles fed along with sheath gas is disposed at the lower portion of the housing (1).