Abstract: An impactor, system and method for performing real-time measurements of particles in aerosol gases. The impactor comprises a plurality of cascading stages having impaction plates, mass-measurement mechanisms retained on the impaction plates, and a nozzle plate. A signal line associated with each of the plurality of cascading stages is configured to relay signals from the mass-measurement mechanism of the associated stage to a computer-based system configured to receive the transmitted signals from the signal lines, and to correlate changes in the resonant frequencies to particle concentrations in real time.

Abstract: A method and apparatus for generating aerosol particles that are substantially uniform in size said apparatus includes a droplet generator comprised of a metal capillary for a liquid to flow through to form a liquid stream flowing into a gas stream. The metal capillary is vibrated by a piezoelectric ceramic at a substantially constant frequency to cause the liquid stream to breakup into droplets that are substantially uniform in size in the gas stream, the gas stream being maintained at a velocity in the range between approximately 10% to 100% of the speed of sound.

Abstract: A method and apparatus are disclosed for exposing particles in a gas in order to cause the charge on the particles to change, the apparatus comprising a chamber having a conductive wall with a gas inlet and a gas outlet. An electrode with an exposed tip is in the chamber, the electrode being held at a different potential from the ground potential. The electrode is connected to a source of voltage sufficient to cause a corona discharge to occur forming ions in the chamber, and creating a region with a high electric field intensity and another region in which the electric field intensity is lower. The inlet and outlet define a gas flow path from the inlet to the outlet such that the gas flow path passes mainly through the region with the lower electric field intensity.

Abstract: A method and apparatus for generating aerosol particles that are substantially uniform in size said apparatus includes a droplet generator comprised of a metal capillary for a liquid to flow through to form a liquid stream flowing into a gas stream. The metal capillary is vibrated by a piezoelectric ceramic at a substantially constant frequency to cause the liquid stream to breakup into droplets that are substantially uniform in size in the gas stream, the gas stream being maintained at a velocity in the range between approximately 10% to 100% of the speed of sound.

Abstract: The present disclosure describes a method and apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: The present disclosure describes an apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: The present disclosure describes an apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: A method for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: The present disclosure describes a method and apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: A method and apparatus are disclosed for exposing particles in a gas in order to cause the charge on the particles to change, the apparatus comprising a chamber with an inlet for the gas to enter and an outlet for the gas to exit. The chamber is surrounded by an enclosure with a conductive wall, the wall being held at a ground potential. An electrode with an exposed tip is in contact with the gas in the chamber, the electrode being held at a different potential from the ground potential. The electrode is connected to a source of voltage sufficient to cause a corona discharge to occur forming ions in the chamber, and creating a region of space with a high electric field intensity and another region of space in which the electric field intensity is lower. The inlet and outlet define a gas flow path from the inlet to the outlet such that the gas flow path passes mainly through the region with the lower electric field intensity.

Abstract: The present disclosure describes a method and apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.

Abstract: The present disclosure has an apparatus for detecting fibers in a gas flowing along a passageway. A laser beam is provided at one end of the passageway and the beam is directed along a length of the passageway through which the gas flows. An electrode system, as disclosed, a quadrupole electrode system is mounted along the passageway to cause fibers carried in the gas to oscillate in a detection zone. A photo detector is positioned laterally of the passageway and detects light scattered by the oscillating fibers and projected through an opening in the passageway to provide an output signal that is a function of the light scattered by the fibers in the detection zone.

Abstract: The present disclosure has an apparatus for detecting fibers in a gas flowing along a passageway. A laser beam is provided at one end of the passageway and the beam is directed along a length of the passageway through which the gas flows. An electrode system, as disclosed, a quadrupole electrode system is mounted along the passageway to cause fibers carried in the gas to oscillate in a detection zone. A photo detector is positioned laterally of the passageway and detects light scattered by the oscillating fibers and projected through an opening in the passageway to provide an output signal that is a function of the light scattered by the fibers in the detection zone.

Abstract: A sampler for removing a sample of gas from a flue or stack utilizes virtual impactor principles, together with a gas jet ejector to insure that the surfaces are kept free of particles. The gas that is, discharged from the sampler thus is not changed in character by contact with particles that may adhere to surfaces of the sampler.

Abstract: A sampler for removing a sample of gas from a flue or stack utilizes virtual impactor principles, together with a gas jet ejector to insure that the surfaces are kept free of particles. The gas that is discharged from the sampler thus is not changed in character by contact with particles that may adhere to surfaces of the sampler.