Pulsed air sampler
AssigneeFemtometrics, Inc.
InventorWilliam D. Bowers
Life of this patent
Estimating the term…
Abstract
A device samples chemicals adsorbed to a surface by applying a pulse of fluid to desorb the particles adhered to the surface. After the pulse of fluid, the region above the surface is enriched with particles dislodged from the surface. Suction is applied in the region above the surface to collect these dislodged particles, which are then transferred to a chemical detector for detection, identification, and quantification. A pulsed air sampler collects particles adhered to a surface and delivers the particles to a chemical sensor. An outlet ejects a fluid, preferably gas, pulse to dislodge particles from the surface and thereby enrich the density of particles above the surface. An inlet collects the dislodged particles for delivery to the chemical sensor.
Claims38
An apparatus for detecting particles that are adhered to a surface, comprising:
- an assembly having an outlet which ejects fluid for desorbing said particles from said surface, and having an inlet which collects a fluid sample comprising said desorbed particles;
- a chemical detector connected to receive said fluid sample;
- and
- a suction pump connected to draw the fluid sample across said chemical detector at a flow rate of 50-1000 cubic centimeters per minute.
A method for collecting particles that are adhered to a surface and are to be detected using a chemical detector, comprising:
- ejecting fluid into said surface thereby desorbing said particles from said surface;
- drawing a fluid sample comprising said desorbed particles into an inlet;
- and
- passing said fluid sample through a passageway extending between the inlet and a chemical detector at a flow rate of 50-1000 cubic centimeters per minute.
A method for collecting particles that are adhered to a surface and are to be detected using a chemical detector, comprising:
- periodically blowing fluid onto said surface thereby desorbing said particles from said surface;
- and
- drawing said desorbed particles into an inlet,
- wherein said drawing and said blowing are alternated.
A portable apparatus for collecting particles that are adhered to a surface, comprising:
- an assembly comprising a handle portion for positioning said apparatus, and a bottom portion having at least one outlet which ejects fluid for desorbing said particles from said surface, and at least one inlet which collects a fluid sample comprising said desorbed particles;
- wherein said at least one outlet is oriented to direct substantially all of said fluid in a first direction and said at least one inlet is oriented to draw substantially all of the fluid sample in a second direction which is opposite to the first direction;
- and
- wherein said fluid in said first direction comprises a fluid pulse at a sufficiently low flow rate and time to enrich the air adjacent said inlet with desorbed particles when said bottom portion is positioned in spaced juxtaposition with said surface, and wherein the fluid sample is drawn at a flow rate of about 50 to 1000 cubic centimeters per minute to prevent substantial dilution of the fluid sample.
Dependencies are inferred from the claim text.