Abstract: A gas sensing element is disclosed as having a measuring gas chamber to which measuring gases are admitted, a diffusion resistance portion for introducing measuring gases to the measuring gas chamber under diffusion resistance, a sensor cell for detecting a specified gas concentration of measuring gases, and an oxygen pump cell for adjusting an oxygen concentration in the measuring gases. The sensor cell includes a measuring electrode, placed facing the measuring gas chamber, and a reference electrode formed in pair with the measuring electrode. The oxygen pump cell includes an inner pump electrode placed facing the measuring gas chamber, and an outer pump electrode formed in pair with the inner pump electrode. The diffusion resistance portion is placed in an area inside of external end walls of the inner pump electrode to be exposed to the measuring gas chamber.

Abstract: A gas sensor control device is disclosed as including a sensor cell having a negative terminal, to which a current-voltage converter is connected, and a differential amplifier is connected to the current-voltage converter to provide a current measured result applied to a microcomputer. The current-voltage converter has an opposite-to-sensor terminal to which another differential amplifier is connected. A sensor-side terminal of the current-voltage converter and another differential amplifier is electrically connected to each other via an electric pathway having a sensor-current flow disabling pathway in which a switch circuit is provided. Closing the switch circuit allows a potential difference between both terminals of the current-voltage converter is zeroed. With the switch circuit closed, the microcomputer calculates an element current correcting value, while detecting an electromotive force of the sensor cell based on which a failure is determined.

Abstract: A ceramic laminate body, a gas sensor element employing such a ceramic laminate body and related manufacturing method are disclosed as including first and second ceramic sheets, made of material compositions different from each other, and an intermediate bonding layer, bonding the first and second ceramic sheets to each other so as to form a closed hollow space between the first and second ceramic sheets. The intermediate bonding layer has a multilayer structure including first and second unit intermediate layers laminated on each other such that innermost end portions of the first and second unit intermediate layers are displaced from each other to adapt a difference in degreasing contraction rates of associated component parts.

Abstract: A gas sensing element is disclosed as having a measuring gas chamber to which measuring gases are admitted, a diffusion resistance portion for introducing measuring gases to the measuring gas chamber under diffusion resistance, a sensor cell for detecting a specified gas concentration of measuring gases, and an oxygen pump cell for adjusting an oxygen concentration in the measuring gases. The sensor cell includes a measuring electrode, placed facing the measuring gas chamber, and a reference electrode formed in pair with the measuring electrode. The oxygen pump cell includes an inner pump electrode placed facing the measuring gas chamber, and an outer pump electrode formed in pair with the inner pump electrode. The diffusion resistance portion is placed in an area inside of external end walls of the inner pump electrode to be exposed to the measuring gas chamber.

Abstract: A gas sensor control device is disclosed as including a sensor cell having a negative terminal, to which a current-voltage converter is connected, and a differential amplifier is connected to the current-voltage converter to provide a current measured result applied to a microcomputer. The current-voltage converter has an opposite-to-sensor terminal to which another differential amplifier is connected. A sensor-side terminal of the current-voltage converter and another differential amplifier is electrically connected to each other via an electric pathway having a sensor-current flow disabling pathway in which a switch circuit is provided. Closing the switch circuit allows a potential difference between both terminals of the current-voltage converter is zeroed. With the switch circuit closed, the microcomputer calculates an element current correcting value, while detecting an electromotive force of the sensor cell based on which a failure is determined.

Abstract: A ceramic laminate body, a gas sensor element employing such a ceramic laminate body and related manufacturing method are disclosed as including first and second ceramic sheets, made of material compositions different from each other, and an intermediate bonding layer, bonding the first and second ceramic sheets to each other so as to form a closed hollow space between the first and second ceramic sheets. The intermediate bonding layer has a multilayer structure including first and second unit intermediate layers laminated on each other such that innermost end portions of the first and second unit intermediate layers are displaced from each other to adapt a difference in degreasing contraction rates of associated component parts.

Abstract: This invention provides a method of manufacturing a ceramic heater which includes the steps of: preparing a ceramic heater base member; applying a platinum paste to a surface of the heater base member so as to form a heater pattern on the surface; applying a ceramic paste to the surface of the heater base member so as to form an insulating layer that covers the heater pattern on the surface; and firing the heater base member with the heater pattern and the insulating layer formed thereon, wherein in the firing step, differences among maximum shrinkage percentages of the heater base member, the heater pattern, and the insulating layer are less than or equal to 5%. With the method, interfacial separation is prevented from occurring at the interfaces among the heater base member, heater pattern, and insulating layer, thus resulting in the ceramic heater having superior insulation properties and durability.

Abstract: A ceramic laminate includes a first ceramic layer and a second ceramic layer which are laminated with each other via a bonding layer. The first ceramic layer has gas permeability. The second ceramic layer has gas impermeability. A method for forming this ceramic laminate includes a step of forming first and second ceramic layer forming green sheets, a step of coating a bonding layer forming paste on the second ceramic layer forming green sheet, and a step of integrally bonding the first ceramic layer forming green sheet with the bonding layer forming paste into a laminated body and then sintering the laminated body.

Abstract: A gas-sensing device is cooled down from 1470° C. to 457° C. after calcination when manufactured. The device comprises a solid electrolyte plate made of partially stabilized zirconia, a measurement electrode disposed on the plate to face an atmosphere of a gas to be measured, and a reference electrode disposed on the plate to face an atmosphere of a reference gas. A gas-permeable diffusion layer is laminated on the plate to cover the measurement electrode. A gas-non-permeable shield layer is laminated on the diffusion layer. A reference-gas-chamber forming plate is laminated on the solid electrolyte plate to form a reference gas chamber. One or more of the shield layer, diffusion layer, and reference-gas-chamber forming plate are made of a material that differs in a contraction percentage from the solid electrolyte plate by an amount of 0.3% or less.

Abstract: A first ceramic sheet and a second ceramic sheet are bonded via an adhesive layer so as to form a closed hollow space between them. A tapered portion with a slant surface is formed at an inner end of the adhesive layer so as to protrude into the closed hollow space. The thickness t1 of the adhesive layer is equal to or smaller than 40 &mgr;m, and the protruding length L1 of the tapered portion is equal to or larger than 2.5 t1.

Abstract: There is provided a hologram with excellent heat resistance. The hologram comprises a hologram film (10) in which a diffraction grating has been recorded, a substrate (11) situated on one side of the hologram film (10) via a bonding material (13), and a polymer film (12) situated on the other side of the hologram film (10) via a bonding material (13), wherein the thickness of the polymer film (12) is no greater than 100 .mu.m. Otherwise, the polymer film (12) is subjected to prior heat treatment. There is further provided a production process for holograms with minimal appearance defects.