Real time infrared aerosol analyzer
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsStanley A. Johnson, Gerald T. Reedy, Romesh Kumar
Life of this patent
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Abstract
Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.
Claims9
Apparatus for analyzing a sample from an aerosol environment, the sample having gaseous elements with suspended particles, comprising,
- means for separating the sample into a plurality of size fractions,
- means for collecting a first fraction in filter means, said collecting means having a first sealed chamber and said filter means being located inside said first chamber,
- means for impacting a second fraction against an internal reflection element to which said second fraction adheres, said impacting means having a second sealed chamber and said internal reflection element being located inside said second chamber, and
- means for analyzing said fractions through infrared spectrophotometry in essentially real time, without removing said filter means from said first chamber, or said internal reflection element from said second chamber,
- said analyzing means including means for emitting infrared light, means for focusing and routing the infrared light through said first and second chambers, means for directing the infrared light alternately through said fractions, and means for measuring the infrared light and identifying the particles.
A method of analyzing a sample from a gaseous environment, the sample having gaseous elements and suspended particles, comprising the steps of
- separating the sample into a plurality of fractions having different size particles,
- capturing particles in a first of said fractions in filter means which collect said first fraction,
- capturing particles in a second of said fractions against an internal reflection element to which said second fraction particles adhere, and
- analyzing said fractions with infrared spectrophotometry in essentially real time by alternating the positions of movable mirrors to direct infrared light emitted from a spectrophotometer alternately through said particle fractions.
Apparatus for analyzing a sample from an aerosol environment, the sample having gaseous elements with suspended particles, comprising,
- means for separating the sample into a plurality of size fractions,
- means for collecting a first fraction in filter means, said collecting means having a first sealed chamber and said filter means being located inside said first chamber,
- means for impacting a second fraction against an internal reflection element to which said second fraction adheres, said impacting means having a second sealed chamber and said internal reflection element being located inside said second chamber, and
- means for analyzing said fractions through infrared spectrophotometry in essentially real time, without removing said filter means from said first chamber, or said internal reflection element from said second chamber, said analyzing means including a plurality of movable mirrors which alternately direct infrared light through said particle fractions, and means for moving said mirrors, whereby said particle size fractions are analyzed alternately in essentially real time.
Apparatus for analyzing a sample from a aerosol environment, the sample having gaseous elements with suspended particles, comprising,
- means for separating the sample into a plurality of fractions each having selected particle sizes,
- a plurality of means for collecting a first selection of fractions in filter means, each fraction being collected in a respective filter means, each collecting means having a first sealed chamber, and each filter means being located inside a respective first chamber,
- a plurality of means for impacting a second selection of fractions against an internal reflection element to which said second selection of fractions adhere, each impacting means having a second sealed chamber and said internal reflection element being located inside a respective second chamber, and
- means for analyzing said fractions through infrared spectrophotometry in essentially real time, without removing said filter means from said first chambers, or said internal reflection element from said second chambers,
- said analyzing means including means for emitting infrared light, means for focusing and routing the infrared light through said first and second chambers, means for directing the infrared light alternately through said fractions, and means for measuring the infrared light and identifying the particles.
Dependencies are inferred from the claim text.