| 摘要 |
A particle sensor(106) for optically detecting an unconstrained particle suspended in a flowing gas includes a sample chamber (135) having a gas inlet (115) and a gas outlet (162); a gas flow system (120) for flowing said gas from said gas inlet through said sample chamber to said gas outlet, a source (134) of light; an optical system (310, 319) directing said light through said sample chamber, an optical collection system (330) located to collect light scattered by said particles in the gas, and a detection system (340) located to detect the collected light. The total pressure drop through said gas flow system is 3 inches of water or less. The gas flow system includes an axial fan (128), which may be a high static pressure fan or a counter-rotating fan. In a 1.0 CFM system, the gas inlet nozzle (130) has an area of 25 square millimeters or more. |
