Water trap and associated control system

Claim 2

A water trap for a respiration gas analyzer, said water trap comprising: a tapered water separation chamber; a sample inlet port connected to the water separation chamber; a sample outlet port connected to the water separation chamber by a sample outlet conduit; a water collection chamber connected to the water separation chamber; a vacuum port connected to the water collection chamber by a vacuum conduit; and at least one self-sealing filter disposed in at least one of the sample outlet conduit and the vacuum conduit, said self-sealing filter comprising a porous matrix having pores characterized by a pore size less than about 100 microns and means, disposed in the porous matrix, for rendering the porous matrix substantially non-porous when exposed to water, said pores forming the only flow path through the filter.

Claim 3

The invention of claim 1 wherein the porous matrix comprises an ultra high molecular weight polyethylene.

Claim 4

The invention of claim 1 wherein the pore size is in the range of about 15-35 microns.

Claim 5

The invention of claim 1 wherein the means for rendering the porous matrix substantially non-porous comprises cellulose.

Claim 6

The invention of claim 1 wherein the at least one self-sealing filter comprises two self-sealing filters, each positioned in a respective one of the conduits.

Claim 7

The invention of claim 5 wherein the chambers, ports, and conduits are molded in a modular assembly which can be handled as a single unit once assembled.

Claim 8

In a gas analyzer of the type comprising a sample cell, a water trap comprising a separation chamber interconnected with a water collection chamber, a low pressure source, and a conduit system comprising a first conduit for conducting a sample gas from an inlet line to the separation chamber, a second conduit for conducting the sample gas from the separation chamber, through the sample cell to the low pressure source, and a third conduit for conducting a gas from the water collection chamber to the low pressure source, the improvement comprising; means, included in the third conduit, for automatically sealing the third conduit upon contact with water; a pressure sensor coupled to the third conduit to generate a pressure signal indicative of a pressure parameter of a selected portion of the third conduit; means, responsive to the pressure signal, for detecting when the pressure signal is indicative of an abnormally low flow through the third conduit; and means, responsive to the detecting means, for indicating an abnormal condition when the detecting means detects the abnormally low flow; said sealing means comprising a self-sealing filter comprising a porous matrix having pores characterized by a pore size less than about 100 microns and means, disposed in the porous matrix, for rendering the porous matrix substantially non-porous when exposed to water, said pores forming the only flow path through the filter.

Claim 9

In a gas analyzer of the type comprising a sample cell, a water trap comprising a separation chamber interconnected with a water collection chamber, a low pressure source, and a conduit system comprising a first conduit for conducting a sample gas from an inlet line to the separation chamber, a second conduit for conducting the sample gas from the separation chamber, through the sample cell to the low pressure source, and a third conduit for conducting a gas from the water collection chamber to the low pressure source, the improvement comprising; means, included in the third conduit, for automatically sealing the third conduit upon contact with water; a pressure sensor coupled to the third conduit to generate a pressure signal indicative of a pressure parameter of a selected portion of the third conduit; means, responsive to the pressure signal, for detecting when the pressure signal is indicative of an abnormally low flow through the third conduit; and means, responsive to the detecting means, for indicating an abnormal condition when the detecting means detects the abnormally low flow; said sealing means comprising a self-sealing filter comprising a porous matrix having pores characterized by a pore size less than about 100 microns and means, disposed in the porous matrix, for rendering the porous matrix substantially non-porous when exposed to water, said pores forming the only flow path through the filter.

Claim 10

The invention of claim 7 wherein the pressure sensor is indicative of a pressure drop across a selected segment of the third conduit and therefore of flow through the selected segment.

Claim 11

The invention of claim 7 wherein the pressure sensor is indicative of pressure within the selected portion of the third conduit.

Claim 12

The invention of claim 7 wherein the indicating means comprises means for displaying an abnormal condition signal when the detecting means detects the abnormally low flow.

Claim 13

The invention of claim 7 wherein the indicating means comprises means for interrupting operation of the low pressure source.

Claim 14

The invention of claim 7 wherein the low pressure source comprises a plurality of pumps.

Claim 15

The invention of claim 7 wherein the sealing means is disposed in the water trap.

Claim 16

The invention of claim 7 wherein the porous matrix comprises an ultra high molecular weight polyethylene.

Claim 17

The invention of claim 14 wherein the pore size is in the range of about 15-35 microns.

Claim 18

The invention of claim 15 wherein the means for rendering the porous matrix substantially non-porous comprises cellulose.