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US 5,312,761 AGranted
Method for measuring trace quantity of oxygen in gas
AssigneeNippon Sanso Corporation
InventorsTakashi Suzuki, Kenkichi Itoh, Hajime Sasaki
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AssigneeNippon Sanso Corporation
InventorsTakashi Suzuki, Kenkichi Itoh, Hajime Sasaki
Estimating the term…
The present invention relates to a method and an apparatus for measuring trace quantity of oxygen in a gas by reacting yellow phosphorus vapor and oxygen in a sample gas, and measuring the intensity of the light emitted by the reaction. Together with the sample gas, a constant amount of oxygen is continuously supplied to a reaction chamber so as to react with the yellow phosphorus vapor, and the intensity of the light emitted is measured. The oxygen concentration in the sample gas is determined from the difference between the value measured as above and the intensity of the light emitted by the reaction between the yellow phosphorus vapor and the added oxygen, or from the oxygen concentration obtained from the measured value and the concentration of the added oxygen. The constant amount of oxygen to be added is supplied by supplying a constant amount of a preliminarily prepared oxygen-containing gas together with the sample gas or by providing an oxygen permeating membrane in the yellow phosphorus vapor supplying system so as to supply the oxygen by the permeation of the oxygen in atmosphere. The small amount of oxygen with a concentration of several ppb in the sample gas can be continuously measured with high precision.
In a method for measuring a trace quantity of oxygen in a gas comprising reacting yellow phosphorus vapor with the oxygen in a sample of said gas to provide light and measuring the quantity of the oxygen in the sample of said gas based on the measured intensity of the light emitted by the reaction, said measured intensity having a non-linear detector response in the range of 0-100 parts-per-billion wherein the improvement comprises continuously supplying a constant amount of oxygen together with the sample of the gas, the amount of oxygen continuously supplied being effective to shift the intensity of the light emitted by the reaction to a range in which the non-linear detector response is substantially removed wherein the measured intensity is the light emitted by the reaction of the yellow phosphorus vapor and both the oxygen in the sample and the oxygen continuously supplied with the sample.
In a method for measuring a trace quantity of oxygen in a gas comprising reacting yellow phosphorus vapor with the oxygen in a sample of said gas to provide light and measuring the quantity of the oxygen in the sample of said gas based on the measured intensity of the light emitted by the reaction, said measured intensity having a non-linear detector response in the range of 0-100 parts-per-billion wherein the improvement comprises continuously supplying a constant amount of oxygen together with the sample of the gas, the amount of oxygen continuously supplied being effective to shift the intensity of the light emitted by the reaction to a range in which the non-linear detector response is substantially removed wherein the measured intensity is the light emitted by the reaction of the yellow phosphorus vapor and both the oxygen in the sample and the oxygen continuously supplied with the sample and determining an oxygen concentration from the difference between the measured amount of light and an intensity emitted by a reaction between the yellow phosphorus vapor and the oxygen continuously supplied.
In a method for measuring a trace quantity of oxygen in a gas comprising reacting yellow phosphorus vapor with the oxygen in a sample of said gas to provide light and measuring the quantity of the oxygen in the sample of said gas based on the measured intensity of the light emitted by the reaction, said measured intensity having a non-linear detector response in the range of 0-100 parts-per-billion wherein the improvement comprises continuously supplying a constant amount of oxygen together with the sample of the gas, the amount of oxygen continuously supplied being effective to shift the intensity of the light emitted by the reaction to a range in which the non-linear detector response is substantially removed wherein the measured intensity is the light emitted by the reaction of the yellow phosphorus vapor and both the oxygen in the sample and the oxygen continuously supplied with the sample;
Dependencies are inferred from the claim text.