Aerosol particle sensor with axial fan
AssigneeParticle Measuring Systems, Inc.
InventorThomas Bates
Life of this patent
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Abstract
A particle sensor for optically detecting an unconstrained particle suspended in a flowing gas includes a sample chamber having a gas inlet and a gas outlet; a gas flow system for flowing said gas from said gas inlet through said sample chamber to said gas outlet, a source of light; an optical system directing said light through said sample chamber, an optical collection system located to collect light scattered by said particles in the gas, and a detection system 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, which may be a high static pressure fan or a counter-rotating fan. In a 1.0 CFM system, the gas inlet nozzle has an area of 25 square millimeters or more.
Claims29
An optical particle sensor for optically detecting unconstrained particles suspended in a flowing gas, said optical particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a high static pressure axial fan or a counter rotating axial fan for flowing gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles;
- wherein the total pressure drop through said inlet jet nozzle is 3 inches of water or less.
An optical particle counter system including a plurality of particle sensors, each particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a high static pressure axial fan or a counter rotating axial fan for flowing gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles;
- wherein the total pressure drop through said inlet jet nozzle is 3 inches of water or less.
An optical particle sensor for optically detecting unconstrained particles suspended in a flowing gas, said optical particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a high static pressure axial fan or a counter-rotating axial fan for flowing said gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet, said gas flow system having a flow rate of substantially 0.1 CFM (cubic feet per minute) and said inlet jet nozzle having a cross-sectional area of 4 mm2 (millimeters squared) or larger;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles.
An optical particle sensor for optically detecting unconstrained particles suspended in a flowing gas, said optical particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a high static pressure axial fan or a counter-rotating axial fan for flowing said gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet, said gas flow system having a flow rate of substantially 1 CFM (cubic feet per minute) and a gas said inlet jet nozzle having a cross-sectional area of 25 mm2 (millimeters squared) or larger;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles.
A method of detecting unconstrained particles in a flowing gas, said method comprising:
- flowing said gas containing said unconstrained particles using a counter-rotating axial fan;
- directing a laser beam through said gas flow;
- collecting light scattered by said particles in said gas;
- and
- detecting said collected light and outputting a signal that is characteristic of a parameter of said particles.
A method of detecting unconstrained particles in a flowing gas, said method comprising:
- flowing said gas containing said unconstrained particles from a gas inlet through a sample chamber to a gas outlet using a high static pressure axial fan or a counter-rotating axial fan, said gas inlet having a total pressure drop of 3 inches of water or less;
- directing a laser beam through said gas flow;
- collecting light scattered by said particles in said gas;
- and
- detecting said collected light and outputting a signal that is characteristic of a parameter of said particles.
A method of detecting unconstrained particles in a flowing gas, said method comprising:
- flowing said gas containing said unconstrained particles using a high static pressure axial fan;
- directing a laser beam through said gas flow;
- collecting light scattered by said particles in said gas;
- and
- detecting said collected light and outputting a signal that is characteristic of a parameter of said particles.
An optical particle sensor for optically detecting unconstrained particles suspended in a flowing gas, said optical particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a high static pressure axial fan for flowing gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles;
- wherein the total pressure drop through said inlet jet nozzle is 3 inches of water or less.
An optical particle sensor for optically detecting unconstrained particles suspended in a flowing gas, said optical particle sensor comprising:
- a sample chamber having a gas inlet and a gas outlet, wherein said gas inlet includes an inlet jet nozzle;
- a gas flow system comprising a counter-rotating axial fan for flowing gas from said gas inlet through said inlet jet nozzle and said sample chamber to said gas outlet;
- a source of light;
- an optical system directing said light through said sample chamber;
- an optical collection system located to collect light scattered by said particles in said gas flowing through said sample chamber;
- and
- a detection system located to detect light collected by said optical collection system, said detection system including an optical detector producing an electric signal characteristic of said particles;
- wherein the total pressure drop through said inlet jet nozzle is 3 inches of water or less.
Dependencies are inferred from the claim text.