Abstract: An oxygen concentration sensor having an oxygen ion conductive solid electrolyte member forming a gas diffusion restricted region into which a measuring gas is introduced, includes a pump current source for supplying a pump current across a pair of electrodes sandwiching the solid electrolyte through a current detection element and a heater for heating the solid electrolyte. By an arrangement in which the current detection element is connected to one of the pair of electrodes facing the gas diffusion restricted region, error of measurement due to leakage of a drive current of the heater is prevented.

Abstract: An air/fuel ratio sensor has an oxygen sensor cell including a primary measuring element in direct contact with a gas such as exhaust gases of an automotive engine, and an oxygen pump cell formed by inner and outer electrodes and a cover of an oxygen ion conductive solid electrolyte which confines the primary measuring element within a gas diffusion control space, and which has a small gas diffusion hole. The primary measuring element is formed with a central opening whose center lies right below the gas diffusion hole, in order to reduce a burden imposed on the oxygen pump cell and prevent overshoot in a sensor response characteristic.

Abstract: A limited current type oxygen sensor comprises a solid electrolyte element formed from material having high oxygen-ion conductivity such as yittria-stabilized zirconia. Electrodes are provided on the top surface and the bottom surface of the element and are formed by calcining a mixture of small ceramic particles that are relatively sinter-retardant as compared with oxygen-ion conducting ceramics, of 200 .ANG. in average particle size fine precious metal particles, and a binder. A cover is provided over the second electrode and the cover includes at least one diffusion orifice that permits ambient gas to diffuse toward the second electrode.

Abstract: An oxygen concentration detection apparatus includes a detection unit having a pair of oxygen-ion conductive solid electrolyte walls forming first and second gas retaining chambers on which first and second sets of electrodes, which are designed to operate alternatively, are provided. First and second current supply circuits are provided for alternatively supplying first and second pump currents respectively on the first and second sets of electrodes. Between the current supply circuits and the sets of electrodes respectively, a first variable resistor and a second variable resistor are provided so that adjustment operations are enabled separately for obtaining an accurate overall output signal characteristic of the oxygen concentration detection apparatus.

Abstract: An air/fuel ratio sensor having two units of probe is disclosed each of which comprises two sensing elements, each having a pair of porous electrodes on oppostie sides of an oxygen ion-conductive solid electrolyte; a gas compartment which is formed in contact with one porous electrode for each sensing element and which communicates with the gaseous atmosphere of interest by way of a gas diffusion limiting portion; and an internal reference oxygen source which is formed in contact with one sensing element on the porous electrode side which is opposite the side where said gas compartment is provided. The oxygen source communicates with the outside by way of a leakage resisting portion. The gas compartment in the first unit of probe communicates directly with the gaseous atmosphere of interest by way of a first gas diffusion limiting portion while the gas compartment in the second unit of probe communicates with the gas in the first unit of probe by way of a second gas diffusion limiting portion.

Abstract: The invention relates to a gas sensor having first and second solid electrolyte cells each of which has a solid electrolyte plate, e.g. a zirconia plate, and a pair of porous electrode layers formed on the opposite surfaces of the plate, spacing means to hold the first and second cells in a narrowly spaced, opposite and parallel arrangement and to define a gas chamber, which admits a gas atmosphere subject to measurement, within the gap between the two cells such that the inner electrode layers of the two cells face each other across the gas chamber and means to appropriately restrict diffusion of the gas atmosphere into the gas chamber. Usually one of the two solid electrolyte cells is used as a concentration cell and the other as an ion pump.

Abstract: A proton conductor gas sensor operable at room temperature for detecting hydrogen or carbon monoxide, and a gas detecting method using the sensor. A pair of electrodes connected to a proton conductor are short-circuited to cause protons to travel through the conductor utilizing the difference in activity between the electrodes or the difference in gas permeability between the electrode and an atmosphere containing the gas to be detected. The potential difference produced in the interior of the conductor by the travel of the protons is obtained as the output of the sensor. This output is in proportion to the concentration of the gas and low in humidity dependence.

Abstract: An air-fuel ratio in the lean range is detected by measuring a limiting current when oxygen diffused to a first electrode is pumped to a second electrode via a solid electrolyte. A stoichiometric air-fuel ratio is detected from electromotive force between first and third electrodes when oxygen is pumped from the first electrode to the third electrode. The invention is characterized by use of such three electrodes. Furthermore, an air-fuel ratio in a rich range is detected by either sending oxygen from the first electrode to the third electrode via the solid electrolyte and measuring a current when the electromotive force between the first and third electrodes is controlled to be constant, or measuring a current when the air-fuel ratio range is judged as "rich" from this electromotive force and the polarity of the impressed voltage at the time of lean detection is reversed.

Abstract: A pump cell element, for an air-fuel ratio sensor, comprising an oxygen ion conductive zirconia solid electrolyte, a pair of layer electrodes coated on the both surface areas of a measuring portion, and ceramic coating layers each coated on each of said electrodes, at least one of said coating layers disposed on the electrode of a minus side of the pump cell element being provided uniformly and dispersedly with through-pores having a converted diameter of 20-500 .mu.m with an average opening percentage of said through-pores is 5-20%. Blackening at the cathode is effectively eliminated.

Abstract: A process for removing oxide contaminants from combustion gas, and employing a solid electrolyte reactor, includes:(a) flowing the combustion gas into a zone containing a solid electrolyte and applying a voltage and at elevated temperature to thereby separate oxygen via the solid electrolyte,(b) removing oxygen from that zone in a first stream and removing hot effluent gas from that zone in a second stream, the effluent gas containing contaminant,(c) and pre-heating the combustion gas flowing to that zone by passing it in heat exchange relation with the hot effluent gas.

Abstract: A method of effecting determination whether a measurement gas is a rich-burned exhaust gas or a lean-burned exhaust gas, by using an oxygen concentration sensor which includes at least one solid electrolyte member of an oxygen-ion conductive material, and at least two electrodes, one electrode being an electrode which is exposed to the measurement gas through diffusion-resistance means, the steps of: applying an electric current to the electrode exposed to the measurement gas through the diffusion-resistance means, such that the electric current flows in one of opposite directions depending upon whether the measurement gas is a rich-burned exhaust gas or a lean-burned exhaust gas, so as to maintain an atmosphere adjacent to the electrode exposed to the measurement gas through the diffusion-resistance means to be stoichiometric; and detecting one of a change in the direction of flow of the electric current, and a change in polarity of a voltage which gives the electric current, and thereby effecting the determ

Abstract: An electrochemical element for detecting a component in a gaseous fluid in an external space, including a planar solid electrolyte body, and a first and a second electrode which are disposed in contact with the planar solid electrolyte body and cooperate with the planar solid electrolyte body to form an electrochemical cell. The electrochemical element has a thin flat space which communicates with the external space and which has a predetermined diffusion resistance to the molecules of the component. A thickness of the thin flat space as measured perpendicularly to a plane of the planar solid electrolyte body is larger at an inlet portion thereof at which the thin flat space communicates with the external space, than at a remote portion thereof remote from the inlet portion. The first electrode is located at the remote portion.

Abstract: An oxygen sensor, suited for measuring the concentration of an oxygen gas contained in an exhaust gas of an automobile, comprises a cell and a heater which is mounted for heating the cell. The heater, including an electrically insulating substrate and a heating element embedded in the substrate, has a recess on one surface thereof and a pair of side wall portions formed by forming the recess. The cell comprises a solid-electrolyte body, a detection electrode, a reference electrode and a chamber enclosing the reference electrode except for its opening. The cell is disposed in the recess of the heater and joined to the heater with an intermediate layer being disposed between the cell and the heater and sintered. The intermediate layer has a number of fine cracks and an intermediate thermal expansion coefficient between these of the solid-electrolyte and the substrate.

Abstract: A method of detecting the concentration of a component in gases, by an electrochemical element comprising a pumping cell having a first and a second electrode on a solid electrolyte layer, and a sensing cell comprising a third and a fourth electrode disposed on another solid electrolyte layer, the first and third electrodes being located adjacent to each other, and exposed to the gas to be measured which has been diffused with a predetermined diffusion resistance. A primary pumping current is applied to the pumping cell to control the partial pressure of the component in the atmosphere adjacent to the first and third electrodes. The primary pumping current is controlled so that an electromotive force induced on the sensing cell concides with a predetermined value.

Abstract: A system is provided for measuring the amount of oxygen in exhaust gas emitted by an internal-combustion engine. The system includes an exhaust pipe for conducting engine exhaust gas and a probe for determining the oxygen content of engine exhaust gases. The exhaust pipe has a side wall formed to include an aperture for continuously discharging a portion of the engine exhaust gas flowing through the pipe. The system further includes a support housing for positioning the probe at a location outside of the exhaust pipe in proximity to the side wall aperture so that the probe is exposed to the engine exhaust gas portion discharged through the aperture and for collecting exhaust gas in a space surrounding the probe. The aperture is sized to permit exhaust gas collected in the support housing to be reintroduced into the exhaust pipe so that collected exhaust gas will be exchanged continuously with exhaust gas flowing through the exhaust pipe.

Abstract: An air/fuel ratio detector for use in measuring or controlling oxygen concentration in exhaust gas from a combustion device, comprising a plurality of solid electrolyte, oxygen ion conducting elements and an electronic control unit. The detector output, which is different over a wide range of air/fuel ratios, from fuel-rich to fuel-lean, enables monitoring of engine operating conditions without having to know beforehand whether the air/fuel ratio is fuel-lean or fuel-rich, and may be used as a feedback control in an internal combustion engine.

Abstract: An A/F (Air Fuel) ratio detector providing precise control of the operating A/F ratio of an internal combustion engine whether the engine is operating in the fuel-rich or fuel-lean region or at the theoretical (stoichiometric) point. The detector includes both a pump element and a sensor element, each composed of an oxygen-ion-conductive solid electrolyte having formed on both sides thereof a porous electrode. The pump and sensor elements are disposed facing one another with a small gap therebetween. A wall is disposed parallel to the sensor element on the side opposite the gap and is sealed to the solid electrolyte of the sensor element except at a base portion, thereby defining an air compartment open to the atmosphere. An electric current is passed through the pump element, and the resulting potential produced across the sensor element is taken as an indication of the operating A/F ratio.

Abstract: An oxygen probe for measuring the characteristics of furnace gases. The probe includes electrodes of a long lasting and relatively inexpensive nickel containing alloy. The probe is formed with apertures and internal passages for ventilating the three phase contact zones between gas, electrolyte, and electrodes with furnace gases, thereby minimizing errors due to catalytic reactions at the electrodes. The probe sheath may be composed of the same alloy as the electrodes, and the electrodes may be fabricated as an integral part of the sheath, so that the sheath serves both as a structural member and as an electrical conductor for conducting voltage generated within the electrodes. A gas pump may be used to assure adequate ventilation to the electrode-electrolyte interfaces.

Abstract: An A/F ratio detector capable of accurately and unambiguously detecting the operating A/F ratio of a burner such as an internal combustion engine whether the engine is operating in the fuel-rich region, fuel-lean region or at the theoretical A/F ratio. The detector includes a solid-electrolyte oxygen pump element having a porous electrode formed on both sides of an oxygen-ion-conductive solid electrolyte, and a solid-electrolyte oxygen-concentration-difference-actuated electrochemical cell sensor element disposed to face the pump element with a small gap therebetween and which has two porous electrodes formed on opposite sides of an oxygen-ion-conductive solid electrolyte. An air compartment open to the atmosphere is formed on a side of the electrochemical cell sensor element opposite the small gap.

Abstract: An air-to-fuel ratio sensor of a construction, wherein an oxygen concentration cell having a chamber, at least one side of which is communicative with the atmosphere and an oxygen pump are disposed in mutual confrontation through a clearance chamber, or a spatial chamber having a tiny hole for dispersion, and gas to be measured is introduced into this clearance chamber or the spatial chamber to measure its air-to-fuel ratio from an output of the oxygen concentration cell or a control quantity of the oxygen pump, thereby making it possible to control the internal combustion engine over a wide range other than its theoretical air-to-fuel ratio.

Abstract: A gas chromatograph for measuring the amounts of selected sample gas components such as oxygen and carbon monoxide. The system comprises a high-temperature (600.degree. C.) zirconia cell detector supplied on one side with a continuous stream of oxygen flowing at a constant rate. A voltage source connected to the zirconia cell transports all of this oxygen to the other side of the cell, resulting in a constant background cell current. Sample components from the chromatographic column are injected sequentially into the oxygen stream. When oxygen is injected the cell current increases due to the increase in total oxygen available for transport through the cell. When carbon monoxide is injected, it is fully combusted with the oxygen, and the current correspondingly decreases due to reduction of the oxygen available for transport. The deviation in cell current with reference to the background current is integrated for each component to produce output signals indicating the amount of the component.

Abstract: A method is provided for increasing the porosity of sintered metal coatings on zirconium oxide ceramics comprising the placing of the metallic coated zirconium oxide part in an acid solution, heating the solution to a temperature below the boiling temperature of the acid, maintaining the part in the acid solution for a sufficient period of time to increase the porosity to a predetermined amount, and removing the part from the acid solution.

Abstract: The reference gas of an electrochemical cell is vented into the process gas being measured at a location sufficiently close to the cell to maintain the gas pressure of the reference gas equal to the gas pressure of the process gas. A packing gland for securing a sensor cell within a support member for high temperature applications is also disclosed.

Abstract: An oxygen meter for measuring the oxygen concentration in a measured gas, having a probe type detecting section carrying at its end a solid electrolyte unit constituting a partition wall, so as to produce a signal corresponding to the difference in the oxygen concentration between the inner side and the outer side of the partition wall. The oxygen meter is adapted to be exposed to the flow of the gas to be measured or into a furnace through a hole formed in the furnace wall, thereby to continuously produce a signal representing the oxygen concentration in the gas to be measured.

Abstract: Determining the oxygen content in gases, particularly combustion exhaust gases, uninfluenced by temperature variations of the gases by passing the gases into a first electrical measuring cell having a solid electrolyte and electrodes connected to a current source. A diffusion-limited electric current flow dependent on the oxygen content of the gases is obtained and measured as a first electrical signal. Passing an auxiliary gas with constant oxygen content into a second measuring cell similar to the first cell and under the same conditions and obtaining a second electrical signal. The quotient of the two electrical signals is a measure of the oxygen content of the gases uninfluenced by temperature variations of the gases.

Abstract: The invention concerns a detector for anhydrides, present in the air or stack gases, which comprises a solid state electrolyte element containing oxy-anions of the particular anhydride to be detected. This solid state element is provided with metal areas to which potentiometric measuring means are connected. The detecting element is, preferably, sintered and may consist of one or several juxtaposed solid state compounds, according as the reference source is a gas or a solid state electrode, respectively. The electrolyte element is heated to a temperature not exceeding its fusion point. In addition, particular arrangements are provided to compensate for the oxygen content variations in air due to varying measurement conditions.