System for detecting fluorescing components in aerosols
AssigneeTSI Incorporated
InventorsPeter P. Hairston, Frederick R. Quant
Life of this patent
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Abstract
An electro-optical aerosol characterizing system includes a continuous wave laser for generating two beams in the red wavelength range, intersecting a particle stream at slightly spaced apart locations. A pulsed UV laser generates a beam that intersects the particle stream at a third location downstream. Laser energy scattered by each particle as it passes the first two locations, is used to compute aerodynamic sizes and UV laser pulsing times, so that in each case the UV beam irradiates the particle at the downstream location. Particles containing biological materials or other fluorescing components emit fluorescence signals in response to the irradiation. Accordingly, the system provides information about particle composition as well as particle size.
Claims40
A process for characterizing particles in aerosols, including:
- causing an aerosol to move along a predetermined path as a stream of successive particles detectable individually at least at first and second different locations along the path;
- accelerating the aerosol along a predetermined segment of the path that includes the first and second locations;
- measuring respective transit times for the particles, with the transit time in each case indicating the time for the respective particle to travel from the first location to the second location;
- intermittently causing excitation energy to intersect the path at a third location downstream of the first and second locations, to individually irradiate each of the particles with the excitation energy, wherein the excitation energy has a frequency within a range selected to trigger a responsive emission by a predetermined constituent;
- and
- responsive to each episode of said irradiating, sensing for the presence of a responsive emission from the particle to facilitate determining whether that particle contains the predetermined constituent.
A particle characterizing system, including:
- a flow generating device for moving an aerosol along a designated path with particles of the aerosol in series, and accelerating the aerosol along a selected segment of the path including first and second different locations along the path;
- a measuring device for measuring transit times indicating respectively for each one of the particles a time for the particle to travel from the first location to the second location;
- an excitation component for generating excitation energy at a frequency within a predetermined excitation frequency range selected to cause an emission by a particle in response to irradiation by the excitation energy, and for causing the excitation energy to intersect the path at a third location downstream of the first and second locations;
- a timing component for causing the excitation component to generate the excitation energy intermittently as the different ones of the particles travel past the third location, thereby to irradiate each of the particles with the excitation energy;
- and
- a sensing component adapted to detect any emission by the particle responsive to the irradiation.
A device for detecting energy emanating from each one of a plurality of particles moving serially along a path as the particles move past a location along the path, including:
- an energy source for causing a first beam of coherent energy and a second beam of coherent energy to intersect a predetermined particle path at respective first and second proximate but different locations;
- an ellipsoidal reflector disposed with respect to the predetermined path to position a first one of its foci along the predetermined path at a selected location proximate the first and second locations;
- and
- a radiant energy detector positioned at a second one of the foci.
A device for studying aerosols with particles traveling serially along a predetermined path, including:
- a first energy source for causing first and second energy beams to intersect an aerosol path at first and second proximate but different locations;
- a second energy source for causing a beam of excitation energy to intersect the path at a third location downstream of the first and second locations;
- a first reflector positioned with respect to the path to receive light emanating from the first and second locations, and shaped to direct the received light toward a first destination;
- a second reflector disposed with respect to the path to receive light emanating from the third location, and shaped to direct the received light toward a second destination;
- a first energy detector disposed at the first destination;
- and
- a second energy detector positioned at the second destination.
Dependencies are inferred from the claim text.