Abstract: A particle detector, having a housing defining a chamber; an air stream injector, producing an airstream in said chamber from air taken from outside said chamber; a light source, producing a light beam that crosses the air stream and wherein said light beam is shaped so that a transverse extent of said light beam has a uniform intensity over said transverse extent of said air stream. Also, a photon detection assembly, including an optical train of lenses, is positioned to accept light from said light beam, emitted by the particles, and to focus this light onto a photon detector. A particle detection assembly detects the particles, responsive to the photon detection assembly. Finally, a particle size estimation assembly estimates size for each detected particle, based on number of photons detected by said photon detection assembly from said particle, as it crosses said light beam.

Abstract: A particle detector, having a housing defining a chamber; an air stream injector, producing an airstream in said chamber from air taken from outside said chamber; a light source, producing a light beam that crosses the air stream and wherein said light beam is shaped so that a transverse extent of said light beam has a uniform intensity over said transverse extent of said air stream. Also, a photon detection assembly, including an optical train of lenses, is positioned to accept light from said light beam, emitted by the particles, and to focus this light onto a a photon detector. A particle detection assembly detects the particles, responsive the photon detection assembly. Finally, a particle size estimation assembly estimates size for each detected particle, based on number of photons detected by said photon detection assembly from said particle, as it crosses said light beam.

Abstract: A particle detector that includes a housing defining a chamber, and an air stream injector, producing an airstream with entrained particles, in the chamber. A light source produces a light beam that intersects with and is wider than the air stream. A light detection assembly detects light generated by scattering of the light beam, by particles in the air stream. A digitizer produces a sequence of scattering digital values, each representing light detected per a first unit of time duration. Additionally, a summing assembly produces a sequence of summed scattering digital values, each equaling a sum of a sequential set of n of the digital values, and wherein successive summed digital values are offset by a the first unit of time duration and overlap by n?1 of the first units of time duration with a nearest neighbor. Finally, a detection assembly processes the summed scattering digital values to detect particles.

Abstract: A method of detecting bioaerosols, including detecting particles and estimating a particle size for each detected particle and determining a fluorescence strength for each detected particle. Comparing particle size and fluorescence strength for each detected particle to arrive at a normalized fluorescence strength per particle and comparing normalized fluorescence strengths over a time period to a maximum threshold, to detect highly fluorescent manmade substances.

Abstract: A particle detector that includes a housing defining a chamber, and an air stream injector, producing an airstream with entrained particles, in the chamber. A light source produces a light beam that intersects with and is wider than the air stream. A light detection assembly detects light generated by scattering of the light beam, by particles in the air stream. A digitizer produces a sequence of scattering digital values, each representing light detected per a first unit of time duration. Additionally, a summing assembly produces a sequence of summed scattering digital values, each equaling a sum of a sequential set of n of the digital values, and wherein successive summed digital values are offset by a the first unit of time duration and overlap by n?1 of the first units of time duration with a nearest neighbor. Finally, a detection assembly processes the summed scattering digital values to detect particles.

Abstract: A method of detecting bioaerosols, including detecting particles and estimating a particle size for each detected particle and determining a fluorescence strength for each detected particle. Comparing particle size and fluorescence strength for each detected particle to arrive at a normalized fluorescence strength per particle and comparing normalized fluorescence strengths over a time period to a maximum threshold, to detect highly fluorescent manmade substances.

Abstract: A particle detector that includes a housing defining a chamber, and an air stream injector, producing an airstream with entrained particles, in the chamber. A light source produces a light beam that intersects with and is wider than the air stream. A light detection assembly detects light generated by scattering of the light beam, by particles in the air stream. A digitizer produces a sequence of scattering digital values, each representing light detected per a first unit of time duration. Additionally, a summing assembly produces a sequence of summed scattering digital values, each equaling a sum of a sequential set of n of the digital values, and wherein successive summed digital values are offset by a the first unit of time duration and overlap by n?1 of the first units of time duration with a nearest neighbor. Finally, a detection assembly processes the summed scattering digital values to detect particles.

Abstract: A particle detector that includes a housing defining a chamber, and an air stream injector, producing an airstream with entrained particles, in the chamber. A light source produces a light beam that intersects with and is wider than the air stream. A light detection assembly detects light generated by scattering of the light beam, by particles in the air stream. A digitizer produces a sequence of scattering digital values, each representing light detected per a first unit of time duration. Additionally, a summing assembly produces a sequence of summed scattering digital values, each equaling a sum of a sequential set of n of the digital values, and wherein successive summed digital values are offset by a the first unit of time duration and overlap by n?1 of the first units of time duration with a nearest neighbor. Finally, a detection assembly processes the summed scattering digital values to detect particles.