Patent ID: 9395281
Filing Date: 2016-07-19
CPC Classification: G01N

Claim Text:
1. An apparatus for measuring a size and number concentration of airborne particles, the apparatus comprising: an elongated gap extending through the apparatus, being bounded on opposing sides by first and second substantially planar surfaces, wherein each of the planar surfaces has a width; a sheath inlet admitting a sheath flow of fluid into the elongated gap, the sheath flow moving away from the sheath inlet in a first flow direction; a mobility separator section downstream of the sheath inlet in the first flow direction, having an electrode forming at least part of the first planar surface of the elongated gap, and a ground plate forming at least part of the second planar surface of the elongated gap, the ground plate being opposed to the electrode; a growth cell downstream of the mobility separator section in the first flow direction, the growth cell including a conditioning section that exposes the sheath flow to at or below ambient temperature; an initiator section downstream of the conditioning section in the first flow direction, wherein the first and second planar surfaces of the elongated gap in the initiator section each comprises a water-saturated evaporative source, the initiator section further comprising a first heat source to expose the sheath flow to a temperature elevated above ambient; and an equilibrator section downstream of the initiator section in the first flow direction, wherein the first and second planar surfaces of the elongated gap in the equilibrator section each comprises a water-saturated evaporative source, the equilibrator section comprising: an observation port through which aerosol particles in the sheath flow illuminated by the laser light are observable.