Abstract: Methods and apparatus for classifying and/or discriminating particles in an aerosol. An example method involves delivering a flow of the aerosol through a nozzle into a sampling volume and directing a plurality of light beams onto an interaction plane in the sampling volume. The plurality of light beams may each be made up of light having one of a corresponding plurality of different wavelengths. For example, the wavelengths may include wavelengths of visible and infrared light or visible, near infrared and short wave infrared light. The method may detect intensities of light from the plurality of light beams that has been scattered at the interaction plane by particles of the aerosol at a plurality of different scattering angles. The resulting data is processed to characterize and/or discriminate the particles.

Abstract: Methods and apparatus for classifying and/or discriminating particles in an aerosol. An example method involves delivering a flow of the aerosol through a nozzle into a sampling volume and directing a plurality of light beams onto an interaction plane in the sampling volume. The plurality of light beams may each be made up of light having one of a corresponding plurality of different wavelengths. For example, the wavelengths may include wavelengths of visible and infrared light or visible, near infrared and short wave infrared light. The method may detect intensities of light from the plurality of light beams that has been scattered at the interaction plane by particles of the aerosol at a plurality of different scattering angles. The resulting data is processed to characterize and/or discriminate the particles.

Abstract: An apparatus for monitoring particulate matter includes a fluid flow passage. Some embodiments include a cartridge defining a part of the fluid flow passage extending from a cartridge inlet to a cartridge outlet and a particle size selector in the fluid-flow passage between the cartridge inlet and the cartridge outlet. The particle size selector comprises a curve section in the fluid flow passage where the flow of fluid undergoes a change in direction and an impact surface extending transversely to the fluid flow passage on an outside of the curve. A particle counter is located downstream from the particle size selector. A pump is connected to drive a flow of a fluid containing the particulate matter through the fluid flow passage. The apparatus may be made compact. Embodiments may be worn and used to monitor exposure of persons to particulate matter.

Abstract: An apparatus for monitoring particulate matter includes a fluid flow passage. Some embodiments include a cartridge defining a part of the fluid flow passage extending from a cartridge inlet to a cartridge outlet and a particle size selector in the fluid-flow passage between the cartridge inlet and the cartridge outlet. The particle size selector comprises a curve section in the fluid flow passage where the flow of fluid undergoes a change in direction and an impact surface extending transversely to the fluid flow passage on an outside of the curve. A particle counter is located downstream from the particle size selector. A pump is connected to drive a flow of a fluid containing the particulate matter through the fluid flow passage. The apparatus may be made compact. Embodiments may be worn and used to monitor exposure of persons to particulate matter.

Abstract: Apparatus and methods for size-specific detection of particles entrained in fluids are provided. A particle size selector separates particles entrained in a sample fluid stream using a curved channel. Shroud fluid streams are interposed between the sample fluid stream and walls of the channel. Centrifugal forces arising from fluid flow through the curved channel separate differently-sized particles into different transverse sections of the channel. A detector downstream from the particle size selector specifically detects particles in one or more transverse sections of the channel.

Abstract: Apparatus and methods for size-specific detection of particles entrained in fluids are provided. A particle size selector separates particles entrained in a sample fluid stream using a curved channel. Shroud fluid streams are interposed between the sample fluid stream and walls of the channel. Centrifugal forces arising from fluid flow through the curved channel separate differently-sized particles into different transverse sections of the channel. A detector downstream from the particle size selector specifically detects particles in one or more transverse sections of the channel.