Abstract Apparatus for determining the oxygen demand of combustible materials in aqueous dispersions and for determining the total carbon content of aqueous systems. The apparatus comprises a combustion tube surrounded by controlled heating means. The combustion tube has sample insertion means and reference gas including oxygen inlet means at an entry end, sample expansion zone and catalyst disposed within the tube, an oxygen detector cell disposed within the tube and gas outlet means coupled to the exit end of the tube. The gas outlet means is coupled to carbon dioxide detection means. Readout means are coupled to both detectors. The reference gas passes through a closed path in the oxygen detector prior to its insertion at the entry end of said combustion tube.
Apparatus in accordance with claim 8, wherein an infra-red detector assembly is coupled to said means for withdrawing gas at said exit end, thereby providing an output signal which is a function of the total carbon content of said sample.
Claim 2
Dependent Claim
23 words
Apparatus in accordance with claim 8, wherein said oxygen detector and said sample are each heated to approximately the same temperature during operation.
Claim 3
Dependent Claim
22 words
Apparatus in accordance with claim 8, wherein said means for heating said combustion tube is a temperature controllable furnace surrounding said tube.
Claim 4
Dependent Claim
33 words
Apparatus in accordance with claim 8, wherein said detector tube is made of a mixture comprising zirconium oxide and calcium oxide and its inner and outer wall surfaces contain a porous platinum coating.
Claim 5
Dependent Claim
16 words
Apparatus in accordance with claim 2, wherein a readout device is coupled to said infra-red detector.
Claim 6
Dependent Claim
26 words
Apparatus in accordance with claim 8, wherein said catalyst is a combustion supporting catalyst which holds oxygen available for reaction on contact with a reducing material.
Claim 7
Dependent Claim
23 words
Apparatus in accordance with claim 1, wherein said means for introducing and withdrawing reference gas from said porous tube extend through said header.
Claim 8
Dependent Claim
20 words
Apparatus in accordance with claim 1, wherein said means for withdrawing gas at said exit end extends through said header.