Gas sensor
AssigneeDynament Limited
InventorDavid Michael Stuttard
Life of this patent
Estimating the term…
Abstract
A gas sensor of the type that detects the presence of a specific gas by monitoring the absorption of optical radiation transmitted through a chamber containing a sample of gas under test comprises an optical source for emmiting radiation therefrom and a detector sensitive to radiation emitted from the source at opposing ends of a circumferential chamber, having optically reflective surfaces, extending around the periphery of a sensor housing The optical pathway between the source and detector may include a radial portion as well as a circumferential portion to allow one or other of the source and detector to be located in a central chamber of the sensor housing.
Claims25
A gas sensor comprising:
- an optical source for emitting radiation therefrom;
- a detector sensitive to radiation emitted from the source;
- an optical pathway extending between the source and the detector;
- a chamber having optically reflective surfaces defining a substantially circular portion of the optical pathway and a substantially radial portion of the optical pathway;
- and
- at least one reflector oriented generally at an oblique angle to the substantially circular portion of the optical pathway to separate the substantially circular portion of the optical pathway and the substantially radial portion of the optical pathway.
A method of forming a gas sensor comprising the steps of:
- providing an optical source for emitting radiation therefrom,
- providing a detector sensitive to radiation emitted from the source,
- providing an optical pathway extending between the source and the detector,
- providing a chamber having optically reflective surfaces defining a substantially circular portion of the optical pathway and a substantially radial portion of the optical pathway;
- and
- providing at least one reflector oriented generally at an oblique angle to the substantially circular portion of the optical pathway to separate the substantially circular portion of the optical pathway and the substantially radial portion of the optical pathway.
A gas sensor comprising
- an optical source for emitting radiation therefrom;
- a detector sensitive to radiation emitted from the source;
- and
- a circumferential chamber having optically reflective surfaces and extending between the source and the detector, the chamber being defined by outer and inner circumferential walls of a substantially cylindrical housing, the chamber including a first end wall, extending radially between the outer and inner circumferential walls to define a first end of the chamber, and a second end wall, generally radially between the outer and inner circumferential walls and at an oblique angle to a tangent of the outer or inner circumferential walls, to reflect light through a gap in the inner circumferential wall into a central chamber, thereby forming an optical pathway between the source and detector thereby comprising a substantially circumferential portion and a radial portion.
A gas sensor comprising:
- an optical source for emitting radiation therefrom;
- a detector sensitive to radiation emitted from the source;
- a circumferential chamber having optically reflective surfaces and extending between the source and the detector, the chamber being defined by outer and inner circumferential walls of a substantially cylindrical housing;
- and
- a chamber cover forming a closure for the cylindrical housing, the chamber cover including a reflective inner surface in combination with a gas permeable member, the gas permeable member covering an annular portion of the circumferential chamber and comprising a disc having a radius greater than a radius of said inner circumferential wall and less than a radius of said outer circumferential wall.
Dependencies are inferred from the claim text.