Abstract: An electrochemical element comprising a laminar structure which includes a porous first layer of fully-stabilized zirconia ceramic, a second layer of partially-stabilized zirconia ceramic, and at least one pair of electrodes. At least one of the at least one pair of electrodes is disposed between the first and second layers, and in contact with the first layer.

Abstract: An electrochemical device such as an oxygen sensor comprising: a plurality of solid electrolyte bodies; at least one pair of electrodes, each pair being disposed such that the electrodes are held in contact with the solid electrolyte bodies separately; at least one conductor sandwiched by two adjacent conductors of the solid electrolyte bodies; and at least one electrical insulation layer. A substantive portion of at least one side of the conductor indirectly contacts one of the two adjacent solid electrolyte bodies via the electrical insulation layer which is disposed therebetween, whereby the conductor is protected from direct contact with the associated solid electrolyte body. The insulation layer further serves to prevent noises which could otherwise be produced due to leakage current from the conductor. The conductor may be a lead connected to one of the electrodes, or to a heater for heating a portion of the solid electrolyte body adjacent the electrodes.

Abstract: An electrochemical device such as an oxygen sensor comprising a plurality of solid electrolyte bodies, at least one pair of electrodes, each pair being disposed such that the electrodes are held in contact with the solid electrolyte bodies separately, at least one conductor sandwiched by two adjacent ones of the solid electrolyte bodies, and at least one electrical insulation layer. A substantive portion of at least one side of the conductor indirectly contacts with one of the two adjacent solid electrolyte bodies via the electrical insulation layer which is disposed therebetween, whereby the conductor is protected from direct contact with the associated solid electrolyte body. The insulation layer further serves to prevent noises which could otherwise be produced due to leakage current from the conductor. The conductor may be a lead connected to one of the electrodes, or a heater for heating a portion of the solid electrolyte body adjacent to the electrodes.

Abstract: A method of manufacturing an electrochemical device having an electrochemical cell including a planar solid electrolyte body and at least two electrodes disposed in contact with the solid electrolyte body. The method comprising: forming a first unfired ceramic layer on one side of an unfired structure of the electrochemical cell, the first unfired ceramic layer being given a porous structure by firing thereof; forming a second unfired ceramic layer on the other side of the unfired structure of the electrochemical cell, the second unfired ceramic layer having substantially the same property of firing shrinkage as the first unfired ceramic layer; and co-firing the unfired structure of the electrochemical cell, the first and second unfired ceramic layers. The two unfired ceramic layers may be formed on opposite sides of an unfired structure of an electrochemical cell assembly which includes plural cells, for example, an oxygen pumping cell and an oxygen sensing cell.

Abstract: An electrochemical element including a planar solid electrolyte body, and at least pair of electrodes including a first electrode and a second electrode which are disposed on the planar solid electrolyte body. The element has a thin flat space which has a predetermined diffusion resistance to a measurement gas and which communicates with an external space in which the measurement gas exists. The first electrode is disposed so that it is substantially exposed to the measurement gas in the thin flat space. The element includes a bridging member which is interposed between two opposed flat surfaces which partially define the thin flat space. The bridging member substantially determines the thickness of the thin flat space. The bridging member is formed by firing a mixture consisting of a filler material which disappears upon firing thereof, and ceramic grains which are fired into the bridging member.

Abstract: An electrochemical device for dealing with a measurement gas in an external measurement-gas space, including an electrochemical sensing element having a pumping cell and a sensing cell. The pumping cell has a first planar solid electrolyte body, and a first and a second electrode disposed on corresponding areas of opposite surfaces of the first solid electrolyte body. The sensing cell has a second planar solid electrolyte body, and a third and a fourth electrode disposed on the second solid electrolyte body. The sensing element has an internal measurement-gas space communicating with the external measurement-gas space, so that the measurement gas is introduced into the internal measurement-gas space with a predetermined diffusion resistance. The first and third electrodes are substantially exposed to the internal measurement-gas space. A reference gas is accommodated in a reference-gas space to which the second and fourth electrodes are substantially exposed to the reference-gas space.

Abstract: An electrochemical device including a sensing element of laminar structure for determining the concentration of a component of a gas, comprising a first electrochemical cell including a first solid electrolyte body, and a first and a second porous electrode disposed on the first solid electrolyte body, a second electrochemical cell including a second solid electrolyte body, and a third and a fourth porous electrode disposed on the second solid electrolyte body, and a ceramic layer having a high electric resistance and sandwiched between the first and second electrochemical cells. In another aspect of the invention, the first solid electrolyte body is porous. In this case, the first and third electrodes are exposed to substantially the same atmosphere. In either case, the first and second, or third and fourth electrodes are disposed in alignment on opposite surfaces of the first or second solid electrolyte body. In the former case, the first and second cells serve as a pumping and sensing cell, respectively.

Abstract: Zirconia powder is formed by dry grinding, and a slurry of the zirconia powder with a nonaqueous solvent is shaped and fired.

Abstract: An electrochemical device of a laminar structure for determining the concentration of a component in a measurement gas, comprising: a pumping cell including a first and a second electrode disposed on a first planar solid electrolyte body; a sensing cell including a third and a fourth electrode disposed on a second planar solid electrolyte body; and a thin flat space to which the first and third electrodes are exposed and which communicates with an external space in which the measurement gas exists. The thin flat space has a diffusion resistance to the component in the measurement gas introduced through an inlet thereof.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

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: A measuring electrode is mounted on one side surface of a solid electrolyte, while a reference electrode is mounted on a separate solid electrolyte and disposed so as to face the opposite side surface of said one solid electrolyte across a gap.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

Abstract: A process of manufacturing an electrochemical device including a pumping cell having a first and a second electrode, and a sensing cell having a third and fourth electrode such that the electrodes are disposed on at least one solid electrolyte body, and the second and fourth electrodes are exposed to the atmosphere in an internal cavity formed in the device. The process comprises a step of interposing an insert consisting essentially of a sublimable material in the cavity to be formed during superposition of green sheets or layers of the solid electrolyte bodies and electrodes into an unfired laminar structure, such that the insert is disposed opposite to the unfired layers of the second and fourth electrodes, and further comprises a step of co-firing the unfired laminar structure incorporating the insert so as to cause the insert to disappear through sublimation.

Abstract: Zirconia powder is formed by dry grinding, and slurry of the zirconia powder with nonaqueous solvent is shaped and fired.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

Abstract: In an electrochemical device having an electrochemical cell with electrodes mounted on a solid electrolyte layer and a heater carried by a ceramic high-electric layer, a resistance ceramic layer is disposed between the solid electrolyte layer and the ceramic layer.

Abstract: In a heating system for heating a ceramic body suitably adapted for, but not limited to, a detector to measure the oxygen concentration of a gaseous mixture such as automobile exhaust gas by using the principle of an oxygen concentration cell made of an oxygen ion conductive solid electrolyte body with electrodes mounted on opposite surfaces thereof, the inventive heater or detector and the method use AC voltage electrode means provided on the solid electrolyte body to apply an AC voltage thereto for heating the heater or detector.

Abstract: A heating element comprises a resistor comprising a plurality of fine particles or thin films having a negative temperature coefficient of electrical resistance, and highly resistant region layers interposed between the fine particles or thin films, at least two separate electrodes arranged in contact with different particles or layers of the resistor, and means for applying across said electrodes an AC electric voltage, said means operable at AC frequencies which are not lower than a frequency whose complex impedance characteristics which when graphed in the manner shown in FIG. 4 hereof correspond to point B of said graphed complex impedance characteristics. This heating element has the following merits that it can be formed into an optional shape, is low in the power consumption, can be rapidly heated, has temperature self-adjusting performance and temperature detecting performance and is excellent in the durability.

Abstract: The disclosed heater with solid electrolyte has a resistor embedded in or tightly secured to a solid electrolyte and an AC power source connected to the resistor, so that heat is generated both in the resistor by an alternating current from the AC power source and in the solid electrolyte by an alternating current flowing therethrough depending on the temperature-sensitive resistance of the solid electrolyte being heated by the resistor.