US3713994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical air pollution monitoring device and method of use thereof
Assignee: United States Atomic Energy Commission
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Filing: 1971-03-16
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Granted: 1973-01-30
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Expires: 1991-03-16
Abstract
Abstract An electrochemical monitoring device has been provided for measuring air pollutants. A thin layer of electrolyte solution is exposed on one side to the atmosphere and on the other side to a mercury pool electrode. Electrochemical reactions which take place at the mercury electrode surface due to the presence of certain pollutants alter the current flow through the mercury pool at a given voltage, thereby providing an indication of the amount of the particular pollutant under study. Since certain important pollutants undergo electrochemical reactions with mercury at different potentials and other pollutants react chemically with mercury, several methods of operation can be used. In one method, selective current responses are obtained for the detection and determination of different pollutants by varying the mercury electrode potential. In a second method, the products of chemical or electrochemical reaction are accumulated in the thin layer of solution or at the electrode surface, and are periodically determined by current coulometric measurement. These two methods can be used jointly and supplement each other.
Inventors
- 👤 W Shults
- 👤 J Kuempel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:00
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
A device for electrochemical monitoring of pollutants in a gaseous medium, comprising: a non-conductive housing having a reservoir compartment therein exposed to said gaseous medium; a mercury pool electrode formed in said reservoir compartment; a porous member disposed in said reservoir compartment and having a surface thereof contiguous with said mercury pool electrode; an electrolyte solution held in suspension by said porous member in contact with the surface of said mercury pool electrode on one side of said porous member and exposed to said gaseous medium on the opposite side of said porous member; a reference electrode disposed in said housing in contact with said electrolyte solution; and means for contrOlling the voltage of said mercury pool electrode relative to said reference electrode and measuring the current flow through said electrolyte solution over said mercury pool electrode as an indication of particular pollutants present in said gaseous medium.
Claim 2
Independent Claim
148 words
A device for electrochemical monitoring of pollutants in a gaseous medium, comprising: a non-conductive housing having a reservoir compartment therein exposed to said gaseous medium; a mercury pool electrode formed in said reservoir compartment; a porous member disposed in said reservoir compartment and having a surface thereof contiguous with said mercury pool electrode; an electrolyte solution held in suspension by said porous member in contact with the surface of said mercury pool electrode on one side of said porous member and exposed to said gaseous medium on the opposite side of said porous member; a reference electrode disposed in said housing in contact with said electrolyte solution; and means for contrOlling the voltage of said mercury pool electrode relative to said reference electrode and measuring the current flow through said electrolyte solution over said mercury pool electrode as an indication of particular pollutants present in said gaseous medium.
Claim 3
Dependent Claim
23 words
The device as set forth in claim 1 further including means for providing a preselected flow of electrolyte solution through said porous member.
Claim 4
Dependent Claim
108 words
The device as set forth in claim 2 wherein said voltage controlling and current measuring means includes an auxiliary electrode disposed in said housing in contact with said electrolyte solution at a point so as to obtain current flow through said electrolyte solution between said mercury pool electrode and said auxiliary electrode, a voltammeter having a controlled voltage output connected electrically to said mercury pool electrode and first and second current sensing inputs connected respectively to said reference electrode and said auxiliary electrode, and a recording means connected to said voltammeter for recording said current flow through said electrolyte at selected voltages applied to said mercury pool electrode.
Claim 5
Dependent Claim
17 words
The device as set forth in claim 3 wherein said reference electrode is composed of saturated calomel.
Claim 6
Dependent Claim
128 words
The device as set forth in claim 2 wherein said means for providing a flow of electrolyte solution through said porous member includes a restricted capillary tube having one end connected in fluid communication with said reservoir compartment for controlling the flow of electrolyte solution to said compartment an exit tube connected in fluid communication with said reservoir compartment at a point so as to allow flow of said electrolyte solution over said mercury pool electrode and a vacuum system connected to the other end of said exit tube so as to pump excess solution from said compartment, thereby providing an even flow of fresh electrolyte solution over said mercury pool electrode to prevent excess concentration of reaction products formed at the mercury electrode and electrolyte solution interface.
Claim 7
Dependent Claim
36 words
The device as set forth in claim 5 wherein said porous member is a filter paper disc and said reservoir compartment is cylindrical in cross section and of a volume to contain said filter paper disc.
Claim 8
Independent Claim
131 words
A method for measuring pollutants in a gaseous medium, comprising the steps of: establishing an electrochemical cell composed of a mercury pool electrode and a layer of electrolyte solution disposed over a surface of said mercury pool electrode and exposed to said gaseous medium; directing a stream of said gaseous medium containing pollutants to be measured onto said exposed area of said electrolyte; pumping said electrolyte solution over said mercury pool electrode at a rate sufficient to prevent excess concentration of reaction products formed at the mercury pool electrode and electrolyte solution interface; applying a voltage to said mercury pool electrode to produce electrochemical reaction with a particular pollutant being measured; and measuring the current flow in said electrolyte solution as an indication of quantity of said particular pollutant being measured.
Claim 9
Independent Claim
131 words
A method for measuring pollutants in a gaseous medium, comprising the steps of: establishing an electrochemical cell composed of a mercury pool electrode and a layer of electrolyte solution disposed over a surface of said mercury pool electrode and exposed to said gaseous medium; directing a stream of said gaseous medium containing pollutants to be measured onto said exposed area of said electrolyte; pumping said electrolyte solution over said mercury pool electrode at a rate sufficient to prevent excess concentration of reaction products formed at the mercury pool electrode and electrolyte solution interface; applying a voltage to said mercury pool electrode to produce electrochemical reaction with a particular pollutant being measured; and measuring the current flow in said electrolyte solution as an indication of quantity of said particular pollutant being measured.
References Cited (Backward Citations)
US3031385A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |