Device and method for detecting the presence of test gas
AssigneeVarian, Inc.
InventorsRoberto Carboneri, Sandro Vittozzi
Life of this patent
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Abstract
A device and a method provide a detection of a presence of a test gas. The device comprises a vacuum chamber connected to a vacuum pump equipped with an electronic power supply unit. At least one portion of the chamber is separated from a surrounding outside environment by a membrane selectively permeable to the test gas. A gas flow from the outside environment is guided forcefully over the surface of the membrane via a flow conveyor, which comprises an inlet duct, a diffuser and an outlet duct. The presence of any test gas is detected by the changes in the electrical current to the vacuum pump provided by the power supply.
Claims20
A device for detecting the presence of a test gas comprising:
- a vacuum chamber;
- a vacuum pump connected to said vacuum chamber;
- a membrane (3) selectively permeable to the test gas and separating at least one portion of said chamber from an outside environment;
- an electronic power supply unit connected to said vacuum pump for detecting a presence of the test gas in said chamber;
- and
- a flow conveyor (5;
- 5′) facing and contacting a surface of said selectively permeable membrane (3) for guiding a gas flow along a particular path from the outside environment directly to the surface of said membrane, diffusing it over the surface of said membrane (3) and exhausting to the outside environment.
A method of detecting the presence of a test gas comprising the steps of:
- providing a vacuum chamber associated with a vacuum pump and a pump power supply;
- separating at least one portion of said chamber from an outside environment by a membrane (3) selectively permeable to the test gas;
- providing a flow conveyer, with an inlet duct, a diffuser and an outlet duct;
- disposing the diffuser of said flow conveyer in communication with the inlet duct and facing and contacting a surface of the membrane;
- reducing pressure within said chamber to a lower pressure than a pressure of the outside environment by means of said vacuum pump;
- guiding a gas flow from the outside environment along a particular path directly onto the surface of the membrane by forcing it successively though the inlet duct to the diffuser, diffusing the gas flow over the surface of the membrane and exhausting it via the outlet duct;
- and
- detecting changes in the electric current to the vacuum pump provided by a power supply thereby indicating a presents of any test gas.
Dependencies are inferred from the claim text.