Devices, systems and methods for detecting particles

Patent metadata

Field	Value
Publication number	US-9915600-B2
Application number	US-201615048199-A
Country	US
Kind code	B2
Filing date	Feb 19, 2016
Priority date	Feb 19, 2016
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A particle detector includes a housing, a light source, and a photo-responsive material. The housing includes a sample inlet and a sample outlet, and encloses a detection cavity. The light source directs irradiating light to particles of a sample fluid flowing in the detection cavity. The photo-responsive material faces the detection cavity, and receives measurement light propagating from the particles in a plurality of measurement light paths angled relative to a longitudinal axis. The particle detector may be utilized to measure scattered light and/or light emitted due to autofluorescence. Fluids sampled may include aerosols, bio-aerosols, and liquids.

First claim

What is claimed is:

1. A particle detector, comprising:
a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity along the longitudinal axis, and to the sample outlet;
a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity; and
a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.

2. The particle detector of claim 1 , wherein the photo-responsive material comprises a semiconductor having a band gap in a range selected from the group consisting of: about 2 eV or less; from about 0.67 eV to about 2 eV; about 1.7 eV or less; from about 0.67 eV to about 1.7 eV; from about 1.1 eV to about 1.7 eV; about 1.1 eV or less; and from about 0.67 eV to about 1.1 eV.

3. The particle detector of claim 2 , wherein the semiconductor comprises crystalline silicon.

4. The particle detector of claim 1 , wherein the detection cavity is generally polygonal and comprises a plurality of planar sides, and the photo-responsive material comprises one or more photo-responsive materials positioned at one or more of the respective sides.

5. The particle detector of claim 1 , wherein the photo-responsive material comprises a plurality of photo-responsive materials, and the plurality of photo-responsive materials comprises at least two photo-responsive materials electrically coupled in series with each other or in parallel with each other.

6. The particle detector of claim 1 , wherein the light source comprises a plurality of light sources.

7. The particle detector of claim 6 , wherein at least one of the light sources is configured for emitting the irradiating light at an irradiating wavelength different from the other light sources.

8. The particle detector of claim 6 , wherein:
the plurality of light sources comprises a first light source and a second light source;
the detection cavity comprises a first detection zone and a second detection zone downstream from the first detection zone;
the first light source is configured for directing a first irradiating light through the first detection zone along the longitudinal axis; and
the second light source is configured for directing a second irradiating light through the second detection zone.

9. The particle detector of claim 8 , wherein the photo-responsive material comprises a first photo-responsive material configured for receiving first measurement light propagating from particles in the first detection zone, and a second photo-responsive material configured for receiving second measurement light propagating from the particles in the second detection zone.

10. The particle detector of claim 8 , wherein the second light source is positioned downstream from the first light source.

11. The particle detector of claim 8 , comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone.

12. The particle detector of claim 8 , wherein the first detection zone and the second detection zone are positioned on the same longitudinal axis.

13. The particle detector of claim 12 , comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone, wherein the second light source is positioned in the housing downstream from the mirror.

14. The particle detector of claim 8 , wherein the longitudinal axis is a first longitudinal axis, the first detection zone is positioned on the first longitudinal axis, and the second detection zone is positioned on a second longitudinal axis oriented at an angle to the first longitudinal axis.

15. The particle detector of claim 1 , wherein:
the housing comprises an axial inlet section on the longitudinal axis between the sample inlet and the detection cavity, and an axial outlet section on the longitudinal axis between the detection cavity and the sample outlet, the axial inlet section and the axial outlet section having respective characteristic dimensions along a transverse direction orthogonal to the longitudinal axis; and
the detection cavity has a characteristic dimension in a range from 0.1% to 200% greater than the characteristic dimension of the axial inlet section and the axial outlet section.

16. The particle detector of claim 1 , comprising a plurality of mirrors in the detection cavity, wherein:
the detection cavity has a dimension along a transverse axis orthogonal to the longitudinal axis; and
the mirrors are configured for reflecting the irradiating light one or more times such that the irradiating light traverses the detection cavity two or more times along directions having a component along the transverse axis.

17. The particle detector of claim 1 , comprising a beam chopper configured for chopping the irradiating light.

18. The particle detector of claim 17 , wherein the beam chopper comprises a fluid moving device configured for moving the sample fluid through the detection cavity.

19. A particle detector, comprising:
a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet, wherein the detection cavity comprises a first detection zone and a second detection zone downstream from the first detection zone;
a first light source configured for directing a first irradiating light to particles of the sample fluid flowing in the first detection zone;
a second light source configured for directing a second irradiating light to particles of the sample fluid flowing in the second detection zone; and
a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.

20. The particle detector of claim 19 , wherein the first light source is configured for emitting the irradiating light at an irradiating wavelength different from the second light source.

21. The particle detector of claim 19 , wherein the photo-responsive material comprises a first photo-responsive material configured for receiving first measurement light propagating from particles in the first detection zone, and a second photo-responsive material configured for receiving second measurement light propagating from the particles in the second detection zone.

22. The particle detector of claim 21 , wherein the photo-responsive material has a configuration selected from the group consisting of:
at least one of the first photo-responsive material and the second photo-responsive material has

Assignees

• Res Triangle Inst

Inventors

• Walls Howard Jerome
• Clayton Anthony Clint
• Newsome Randall J
• Hoertz Paul G

Classifications

• G01N2015/1493

  Particle size · CPC title

• G01N2015/0046

  in gas, e.g. smoke · CPC title

• G01N15/0205

  by optical means · CPC title

• G01N15/1459

  the analysis being performed on a sample stream · CPC title

• G01N2015/1486

  Counting the particles · CPC title