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US 4,288,749 AGranted
Method and apparatus for measuring oxygen concentration
AssigneeGenerale de Fluide
InventorFernand R. C. Murtin
Life of this patent
Estimating the term…
Abstract
A process for measuring the concentration of oxygen in a gaseous mixture, and particularly for determining the percentage of oxygen in the exhaust gases of an internal or external combustion engine, and ionization probes for the carrying out of this process.
Claims11
Apparatus for measuring the oxygen concentration in a gas comprising:
- an ionization-probe comprising an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- a high voltage DC source connected to said flat electrode for providing current to said flat electrode at a voltage sufficiently high to generate successive electric discharges between said electrodes at substantially atmospheric pressure;
- regulating means for holding substantially constant the ratio of the voltage of said DC source to the current in said pointed electrode as oxygen concentration varies;
- and
- processing circuitry connected to said pointed electrode for measuring the average value of the current flowing therein.
2 more elements
A method for measuring the oxygen concentration in a gaseous mixture comprising the steps of:
- passing said gaseous mixture through an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- applying to one of said electrodes a voltage sufficiently high to generate successive electric discharges producing ionization of said gaseous mixture at substantially atmospheric pressure;
- measuring the average value of the current flowing between said electrodes;
- and
- regulating said applied voltage so as to maintain substantially constant the ratio of said applied voltage to said current flowing between said electrodes as oxygen concentration varies.
2 more elements
A method for measuring the oxygen concentration in a gaseous mixture comprising the steps of:
- passing said gaseous mixture through an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- applying to one of said electrodes a voltage sufficiently high to generate successive electric discharges producing ionization of said gaseous mixture at substantially atmospheric pressure;
- measuring the frequency of electric discharges appearing between said electrodes;
- and
- regulating said applied voltage so as to maintain substantially constant the ratio of said applied voltage to the current flowing between said electrodes as oxygen concentration varies.
2 more elements
Apparatus for measuring the oxygen concentration in a gaseous mixture comprising:
- an ionization-probe comprising an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- a high voltage DC source connected to said flat electrode, said high voltage being sufficiently high to automatically generate successive electric discharges between said electrodes at substantially atmospheric pressure;
- regulating means receiving the current flowing in said pointed electrode and comprising integration and amplifier means for regulating the voltage of said source in response of variations of said current as oxygen concentration varies;
- and
- processing circuitry connected to said pointed electrode for measuring the average value of the current flowing therein.
2 more elements
A method for measuring the oxygen concentration in a gaseous mixture comprising the steps of:
- (a) passing said gaseous mixture through an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- (b) applying to one of said electrodes a DC voltage sufficiently high to generate successive electric discharges producing ionization of said gaseous mixture at substantially atmospheric pressure;
- (c) measuring the average value of the current flowing in the other electrode as oxygen concentration varies;
- and
- (d) regulating said applied voltage in response to variations of said average value of said current flowing in said other electrodes.
2 more elements
A method for measuring the oxygen concentration in a gaseous mixture comprising the steps of:
- (a) passing said gaseous mixture through an ionization cell having a substantially flat electrode and a pointed electrode disposed substantially perpendicular to said flat electrode at a short distance therefrom;
- (b) applying to one of said electrodes a DC voltage sufficiently high to generate successive electric discharges producing ionization of said gaseous mixture at substantially atmospheric pressure;
- (c) regulating said applied voltage in response to variations of the average value of the current flowing in the other of said electrodes as oxygen concentration varies;
- and
- (d) measuring the frequency of electric discharges appearing between said electrodes.
2 more elements
Dependencies are inferred from the claim text.