US 5,222,389 AGranted

Multi-channel gas sample chamber

AssigneeGaztech International Corporation

InventorJacob Y. Wong

Life of this patent

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Abstract

A gas sample chamber for use in a gas analyzer consists of an elongated hollow tube having an inwardly-facing specularly-reflective surface that permits the tube to function also as a light pipe for conducting radiation from a source to a detector through the sample gas. A number of apertures in the wall of the elongated hollow tube permit the sample gas to enter and exit. Particles of smoke and dust of a size greater than 0.1 micron are kept out of the chamber by use of a semi-permeable membrane that spans the apertures in the hollow tube. Condensation of the sample gas components is prevented by heating the sample chamber electrically to a temperature above the dew point of the component of concern. In one embodiment, at least one detector are spaced around the periphery of the elongated hollow tube adjacent one end of it. In another embodiment, at least one detector are spaced along the length of the elongated hollow tube.

Claims6

Dependent claims

A multi-channel diffusion-type gas sample chamber for conducting radiation through a gas, comprising in combination:

an elongated hollow tube having a wall, composed of a gastight material, and having an inwardly-facing specularly-reflective surface that conducts radiation introduced at one end of said elongated hollow tube toward the other end with high efficiency by means of multiple reflections from said inwardly-facing specularly-reflective surface, said elongated hollow tube having a plurality of apertures extending through the wall and located intermediate the ends of said elongated hollow tube, said elongated hollow tube further having a plurality of detector ports extending through the wall of said elongated hollow tube;
and,
a sheet of a semi-permeable membrane covering each of said plurality of apertures, said sheet permitting airborne particles smaller than a specific size to diffuse through it into and out of the space within said elongated hollow tube and preventing airborne particles larger than said specific size from entering said space.

Dependencies are inferred from the claim text.

Facts

Application: 07/816,596Filed 31 Dec 1991 · continuation in part
Priority: 2 Apr 1990
Granted: 29 Jun 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

G01N 1/2258
Sampling from a flowing stream of gas: in a stack or chimney
G01N 21/05
Cuvette constructions: flow-through cuvettes
G01N 21/3504
Using infrared light: for analysing gases, e.g. multi-gas analysis
G01N 33/0011
General constructional details of gas analysers, e.g. portable test equipment: sample conditioning

Family

Serial503,216Parent of this continuation-in-part · filed 2 Apr 1990
Serial604,615Parent of this continuation · filed 26 Oct 1990
US 5,060,508 AParent of this continuation-in-part · filed 29 Oct 1991
Serial793,990Parent of this continuation-in-part · filed 18 Nov 1991
US 5,163,332 AParent of this continuation-in-part
US 5,222,389 AThis patent

From the US filing history. Foreign family members aren’t listed.