Patent US3915644A successfully refreshed from Google Patents.
US3915644A
Expired / Lapsed
US
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Method and apparatus for determining concentrations by the analysis of reaction rates in continuously and discontinuously flowing samples
Assignee: Cenco Medican Industries Inc
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Filing: 1974-03-26
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Granted: 1975-10-28
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Expires: 1994-03-26
Abstract
Abstract A method and apparatus for determining the concentration of a substance in a fluid is disclosed. The substance is mixed with one or more other components in a duct to form a reaction mixture of which at least one physical or chemical property undergoes a measurable change during a certain time span after formation of the mixture, the rate of change being dependent upon the concentration of the substance. Appropriate detecting and analyzing devices are utilized to transform the rate of change in the property into an indication of the concentration.
Inventors
- 👤 Willem Walraven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:40
CPC Classifications
G; G01; G01N; G01N31/00; Y; Y10; Y10S; Y10S435/00; Y10S435/808
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
186 words
A METHOD OF DETERMINING THE CONCENTRATION OF A SUBSTANCE IN A FLUID COMPRISING: PASSING A REAGENT THAT REACTS IN THE PRESENCE OF THE SUBSTANCE OF WHICH THE CONCENTRATION IS BEING MEASURED THROUGH A CONDUIT AT A PREDETERMINED CONSTANT VELOCITY, INSERTING A SAMPLE OF THE FLUID INTO THE CONDUIT FOR A DESIGNATED PERIOD OF TIME TO FORM A REACTION MIXTURE, MEASURING A PHYSICAL OR CHEMICAL PROPERTY WHICH IS KNOWN TO CHANGE DURING THE REACTION OF THE REAGENT AT A RATE DETERMINED BY THE CONCENTRATION OF THE SUBSTANCE AT SPACED SITES ALONG THE CONDUIT DOWNSTREAM OF THE POINT WHERE THE SAMPLE OF THE SUBSTANCE IS INTRODUCED INTO THE CONDUIT SO THAT THE REACTION STATES AT THE SITES DIFFER DURING CERTAIN TIME PERIODS BY A CONSTANT AMOUNT REPRESENTING A FIXED TIME DIFFERENTIAL OF THE REACTION, DETERMINING THE DIFFERENCE BETWEEN THE MEASUREMENTS AT THE SPACED SITES DURING A TIME WHEN THE REACTION STATES AT THE SITES ARE SUCH THAT CONSTANT MEASUREMENTS ARE PRODUCED AND COMPARING THE DIFFERENCE IN THE MEASUREMENTS OF THE REACTION MIXTURE WITH THE DIFFERENCE WHEN ONLY THE REAGENT IS PRESENCE TO DETERMINED THE CONCENTRATION OF THE SUBSTANCE.
Claim 2
Independent Claim
186 words
A METHOD OF DETERMINING THE CONCENTRATION OF A SUBSTANCE IN A FLUID COMPRISING: PASSING A REAGENT THAT REACTS IN THE PRESENCE OF THE SUBSTANCE OF WHICH THE CONCENTRATION IS BEING MEASURED THROUGH A CONDUIT AT A PREDETERMINED CONSTANT VELOCITY, INSERTING A SAMPLE OF THE FLUID INTO THE CONDUIT FOR A DESIGNATED PERIOD OF TIME TO FORM A REACTION MIXTURE, MEASURING A PHYSICAL OR CHEMICAL PROPERTY WHICH IS KNOWN TO CHANGE DURING THE REACTION OF THE REAGENT AT A RATE DETERMINED BY THE CONCENTRATION OF THE SUBSTANCE AT SPACED SITES ALONG THE CONDUIT DOWNSTREAM OF THE POINT WHERE THE SAMPLE OF THE SUBSTANCE IS INTRODUCED INTO THE CONDUIT SO THAT THE REACTION STATES AT THE SITES DIFFER DURING CERTAIN TIME PERIODS BY A CONSTANT AMOUNT REPRESENTING A FIXED TIME DIFFERENTIAL OF THE REACTION, DETERMINING THE DIFFERENCE BETWEEN THE MEASUREMENTS AT THE SPACED SITES DURING A TIME WHEN THE REACTION STATES AT THE SITES ARE SUCH THAT CONSTANT MEASUREMENTS ARE PRODUCED AND COMPARING THE DIFFERENCE IN THE MEASUREMENTS OF THE REACTION MIXTURE WITH THE DIFFERENCE WHEN ONLY THE REAGENT IS PRESENCE TO DETERMINED THE CONCENTRATION OF THE SUBSTANCE.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1 wherein said measuring step comprises measuring the opacity of the reagent and the reaction mixture.
Claim 4
Dependent Claim
39 words
A method as claimed in claim 1 wherein said passing and inserting steps further comprise moving the reaction mixture through parallel branches of the conduit with differing flow rates, a measurement site being located in each of the branches.
Claim 5
Dependent Claim
22 words
A method as claimed in claim 1 wherein said passing step further comprises passing another liquid through the conduit with the reagent.
Claim 6
Dependent Claim
30 words
A method as claimed in claim 1 wherein said passing step further comprises varying the flow through the conduit to adjust the time difference between measurements at the measuring sites.
Claim 7
Dependent Claim
31 words
A method as claimed in claim 1 wherein said passing step further comprises stopping the flow through the conduit to reduce the effects of flow phenomena and shift the measuring times.
Claim 8
Independent Claim
209 words
An apparatus for determining the concentration of a substance in a fluid comprising: a source of a reagent that reacts with the substance of which the concentration is being measured; a conduit; pump means to force said reagent through said conduit at a predetermined constant velocity; a supply of the fluid containing the substance; a sample extracting means to draw fluid from said supply for a designated period of time, said pump means inserting the fluid into said conduit to form a reaction mixture; first and second spaced measuring sites in said conduit; measuring means at said measuring sites to measure a property of the liquid flowing through said conduit, said property being a property that is known to change during reaction of said reagent at a rate determined by the concentration of the substance; detecting means to produce a signal indicative of the difference between the measurements at said measuring sites; and comparing means to compare the output of said detecting means when only reagent is in the conduit and the output of said detecting means when said reaction mixture is at said measuring sites and the measurements of said measuring means at both sites is constant to thereby determine the concentration of the substance in the fluid.
Claim 9
Independent Claim
209 words
An apparatus for determining the concentration of a substance in a fluid comprising: a source of a reagent that reacts with the substance of which the concentration is being measured; a conduit; pump means to force said reagent through said conduit at a predetermined constant velocity; a supply of the fluid containing the substance; a sample extracting means to draw fluid from said supply for a designated period of time, said pump means inserting the fluid into said conduit to form a reaction mixture; first and second spaced measuring sites in said conduit; measuring means at said measuring sites to measure a property of the liquid flowing through said conduit, said property being a property that is known to change during reaction of said reagent at a rate determined by the concentration of the substance; detecting means to produce a signal indicative of the difference between the measurements at said measuring sites; and comparing means to compare the output of said detecting means when only reagent is in the conduit and the output of said detecting means when said reaction mixture is at said measuring sites and the measurements of said measuring means at both sites is constant to thereby determine the concentration of the substance in the fluid.
Claim 10
Dependent Claim
14 words
Apparatus as claimed in claim 7 wherein said pump means is a tubing pump.
Claim 11
Dependent Claim
28 words
Apparatus as claimed in claim 7 wherein: said conduit comprises parallel branches having different flow rates therein; and one of said measuring sites is located in each branch.
Claim 12
Dependent Claim
40 words
Apparatus as claimed in claim 7 wherein said measuring means comprises: a light source; and a photoelectric cell at each of said measuring sites, each of said cells positioned with said conduit between the photoelectric cell and said light source.
Claim 13
Dependent Claim
37 words
Apparatus as claimed in claim 7 wherein said comparing means comprises a recorder to register the output of said detecting means and provide a graphical representation so that the concentration of said substance may be readily determined.
Claim 14
Dependent Claim
45 words
Apparatus as claimed in claim 7 wherein said pump means is also connected to said conduit downstream of said measuring sites preventing free drainage from said conduit, whereby stopping said pump means fixes the conditions in said conduit by eliminating the effects of flow phenomena.
Claim 15
Independent Claim
291 words
An apparatus for determining the concentration of a substance in a fluid comprising: a source of a reagent that reacts in the presence of the substance of which the concentration is being measured; a conduit; a tubing pump to force said reagent through said conduit at a predetermined constant velocity; a supply of the fluid containing the substance of which the concentration is being measured; a sample extracting means to draw fluid from said supply for a designated period of time, said tubing pump inserting the fluid into said conduit to form a reaction mixture; first and second measuring sites located along said conduit with a predetermined spacing therebetween; a light source located in the vicinity of said measuring sites; a first photoelectric cell located on the side of said conduit opposite said light source at said first measuring site; a second photoelectric cell located on the side of said conduit opposite said light source at said second measuring site, said first and secoNd photoelectric cells detecting changes in the opacity of the liquid in said conduit, the opacity of the liquid changing during reaction of said reagent at a rate determined by the concentration of the substance; detecting means to produce a signal indicative of the difference between the voltage potentials produced by said photoelectric cells; adjusting means to set said difference signal produced by said detecting means at a desired level prior to production of said reaction mixture; and recording means to continuously register said difference signal produced by said detecting means in a graphical representation so that the concentration of the substance may be readily determined by comparing the graphical representations when only said reagent is in said conduit and when said reaction mixture is in said conduit.
Claim 16
Independent Claim
291 words
An apparatus for determining the concentration of a substance in a fluid comprising: a source of a reagent that reacts in the presence of the substance of which the concentration is being measured; a conduit; a tubing pump to force said reagent through said conduit at a predetermined constant velocity; a supply of the fluid containing the substance of which the concentration is being measured; a sample extracting means to draw fluid from said supply for a designated period of time, said tubing pump inserting the fluid into said conduit to form a reaction mixture; first and second measuring sites located along said conduit with a predetermined spacing therebetween; a light source located in the vicinity of said measuring sites; a first photoelectric cell located on the side of said conduit opposite said light source at said first measuring site; a second photoelectric cell located on the side of said conduit opposite said light source at said second measuring site, said first and secoNd photoelectric cells detecting changes in the opacity of the liquid in said conduit, the opacity of the liquid changing during reaction of said reagent at a rate determined by the concentration of the substance; detecting means to produce a signal indicative of the difference between the voltage potentials produced by said photoelectric cells; adjusting means to set said difference signal produced by said detecting means at a desired level prior to production of said reaction mixture; and recording means to continuously register said difference signal produced by said detecting means in a graphical representation so that the concentration of the substance may be readily determined by comparing the graphical representations when only said reagent is in said conduit and when said reaction mixture is in said conduit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |