Patent ID: 6263744
Filing Date: 2001-07-24
Classification: G01N

Abstract:
A particle detection system, comprising:an input port to receive a gaseous flow having particles;a particle classifier having a particle chamber to receive an input sample flow derived from said gaseous flow, operable to classify said particles according to dimension of said particles and to export classified particles in a sampled output flow and unclassified particles in a unsampled output flow, wherein said particle chamber includes a first inlet to receive said input sample flow, a second inlet to receive a sheath flow derived from said gaseous flow, a sample exit to export said sampled output flow, and an unsampled exit to export said unsampled output flow; anda particle counting device having a flow inlet connected to receive said sampled output flow and a flow exit, operating to measure a number of particles in said sampled output flow;a flow control module to control flow rates of said input sample flow, said sheath flow, said sampled output flow, and said unsampled output flow in a relation with one another, said flow control module including:a first flow conduit connected to receive said gaseous flow and to partition a portion of said gaseous flow as said input sample flow;a second flow conduit, having a particle-eliminating filter therein, disposed to partition another portion of said gaseous flow as said clean sheath flow;whereby said system is operable to obtain a number distribution of said particles in the gaseous sample with respect to said dimension of said particles.