Abstract: A gas sensor element is provided which is designed to measure the concentration of hydrogen-containing gas accurately. The sensor element includes an oxygen pump cell working to keep the concentration of oxygen contained in measurement gasses entering a measurement gas chamber at a low concentration level and a hydrogen-containing gas measurement cell. The hydrogen-containing gas measurement cell is made up of a proton-conductive solid electrolyte body and a first and a second gas measurement electrode affixed to the proton-conductive solid electrolyte body. The first gas measurement electrode is exposed to the measurement gas chamber and serves to produce a signal between the first and second gas measurement electrodes as a function of the concentration of the hydrogen-containing gas.

Abstract: An objective gas is successively introduced into first and second chambers which are connected via a narrow passage. A first monitor cell, provided on a surface of the first chamber, generates an electromotive force representing an oxygen concentration in the first chamber. A second monitor cell, provided on a surface of the second chamber, generates an electromotive force representing an oxygen concentration in the second chamber. A voltage applied to a pump cell is controlled based on the electromotive forces obtained from the first and second monitor cells.

Abstract: A gas sensor includes a measurement gas chamber into which a measurement gas is introduced. An oxygen pumping cell adjusts an oxygen concentration in the measurement gas chamber. An oxygen monitor cell has a monitor electrode exposed in the measurement gas chamber. The monitor electrode has an oxidizing activity with respect to a specific component of the measurement gas. A sensor cell has a sensor electrode exposed in the measurement gas chamber. The sensor electrode has an oxidizing activity with respect to the specific component of the measurement gas which is lower than the oxidizing activity of the monitor electrode. An oxygen-ion current in the oxygen monitor cell is detected. An oxygen-ion current in the sensor cell is detected. A concentration of the specific component of the measurement gas is detected from a relation between the detected oxygen-ion currents in the oxygen monitor cell and the sensor cell.

Abstract: When producing a ceramic element formed of a metal oxide sintered body as a principal component thereof, this invention contemplates to make further uniform a composition of a ceramic raw material and to reduce the variance of a resistance value of the ceramic element. A production method of the invention comprises a step of preparing a precursor solution by mixing a precursor of a metal oxide in a liquid phase, a step of spraying the precursor solution and obtaining droplet particles, a step of heat-treating the droplet particles and obtaining thermistor raw material powder, and a step of molding and sintering the thermistor raw material powder into a predetermined shape and obtaining a metal oxide sintered body.

Abstract: A gas sensor consists of a pump cell, a monitor cell, and a sensor cell. The sensor cell is supplied with power to produce a sensor cell current. The monitor cell is supplied with power to produce a monitor cell current. A sensor cell and a monitor cell current detector are disposed between a sensor cell electrode exposed to a gas cavity and a sensor cell power supply and between a monitor cell electrode exposed to the gas cavity and a monitor cell power supply, thereby enabling the sensor cell current and the monitor cell current to be measured without addition of electric noises arising from current components flowing from the monitor cell to the sensor cell and vice versa.

Abstract: A gas sensor is disclosed which attains high response speed, low power consumption, superior water splash resistance and a little setting direction dependency and setting angle dependency. In this gas sensor, a measured gas room is provided inside an inner cover, and gas passage holes for leading a measured gas in are provided on side surfaces of the inner cover and an outer cover. The gas passage holes provided on the outer cover are positioned much closer to a top end side than the gas passage hole provided closest to the top end side in the inner cover. Partitions disposed extendedly in an axial direction of the gas sensor are provided between the outer cover and the inner cover.

Abstract: A gas sensor element consists of an oxygen pump cell, an oxygen monitor cell, and a sensor cell. The oxygen monitor cell measures the concentration of the oxygen molecules within the gas cavity which is fed back to the oxygen pump cell for keeping the concentration of oxygen molecules within the gas cavity constant. The sensor cell ionizes a specified oxygen containing gas and produce a signal indicative of the concentration of the specified oxygen containing gas within the gas cavity. The oxygen monitor cell and the sensor cell are disposed at substantially the same location in a direction of flow of the gasses, thereby minimizing a difference in concentration of oxygen molecules around the oxygen monitor cell and the sensor cell for eliminating an error of the signal outputted from the sensor cell arising from a variation in concentration of oxygen molecules within the gas cavity.

Abstract: This invention provides a reducing-atmosphere-resistant thermistor element, the resistance of which does not greatly change even when the element is exposed to a reducing atmosphere, and which has high accuracy and exhibits excellent resistance value stability. The thermistor element has a construction in which an oxygen occlusion-release composition, having oxygen occlusion-release characteristics, such as CeO2 is dispersed in a composition containing a mixed sintered body (M1 M2)O3.AOx as a principal component. The oxygen occlusion-release composition emits absorbed oxygen in a reducing atmosphere and suppresses migration of oxygen from the composition constituting the element. Therefore, the resistance value does not greatly change even when the element is exposed to a reducing atmosphere, and the element can accurately detect the temperature for a long time. The present invention can thus provide a temperature sensor having high reliability.

Abstract: A highly accurate reduction resistant thermistor exhibiting stable resistance characteristics even under conditions where the inside of a metal case of a temperature sensor becomes a reducing atmosphere, wherein when producing the thermistor comprised of a mixed sintered body (M1 M2)O3·AOx, the mean particle size of the thermistor material containing the metal oxide, obtained by heat treating, mixing, and pulverizing the starting materials, is made smaller than 1.0 &mgr;m and the sintered particle size of the mixed sintered body, obtained by shaping and firing this thermistor material, is made 3 &mgr;m to 20 &mgr;m so as to reduce the grain boundaries where migration of oxygen occurs, suppress migration of oxygen, and improve the reduction resistance.

Abstract: An element portion of a thermistor element is composed of a mixed sintered body (MM′)O3·AOx of a composition of a complex perovskite oxide presented as (MM′)O3, and a metallic oxide presented as AOx. In said complex perovskite oxide (MM′)O3, M is at least one element selected from the elements of the groups 2A and 3A excluding La in the Periodic Table, and M′ is at least one element selected from the elements of the groups 3B, 4A, 5A, 6A, 7A and 8 in the Periodic Table. Said metallic oxide AOx is a heat-resistant, metallic oxide having a melting point of 1300° C. and more, and a resistivity of AOx itself at 100° C. in the form of a thermistor element is 1000&OHgr; or more.

Abstract: An objective gas is successively introduced into first and second chambers which are connected via a narrow passage. A first monitor cell, provided on a surface of the first chamber, generates an electromotive force representing an oxygen concentration in the first chamber. A second monitor cell, provided on a surface of the second chamber, generates an electromotive force representing an oxygen concentration in the second chamber. A voltage applied to a pump cell is controlled based on the electromotive forces obtained from the first and second monitor cells.

Abstract: A gas sensor has a housing, a gas sensing element held by the housing and having a gas contact portion and an element cover for covering the gas contact portion. The element cover has a double pipe structure formed by layering an outer pipe and an inner pipe. The outer pipe has an outer bottom portion having an outer bottom hole and an outer side portion having plural outer side holes. The inner pipe has an inner bottom portion having an inner bottom hole and an inner side portion having plural inner side holes disposed not to overlap the outer side holes. A spacing D of 0.2-1.0 mm is formed between the outer bottom portion and the inner bottom portion. As a result, flow resistance in the spacing D is relatively high, and the sample gas sufficiently and more smoothly flows toward the gas sensing element. Therefore, the element cover prevents condensed water from entering the inside of the gas sensor and improves response of the gas sensor.

Abstract: A gas concentration detecting device for detecting the concentration of a component, such as an oxygen in an exhaust gas of an internal combustion engine. The device has a concentration detecting body 2 for detecting the oxygen and a cover 3 of a double wall structure which is for encircling the portion of the detecting body opened to the flow of the exhaust gas to be detected. The cover 3 has, at its axial tip end wall, a plurality of holes 33 and 34 arranged in such a manner that one of the holes functions as a gas inlet hole and the other hole functions as a gas outlet hole in order to cause the gas to be smoothly ventilated. The cover has, at its side, a wall of a closed structure with no hole for the passage of the gas, which is effective for preventing the cover 3 and the detecting body 2 from being cooled by the exhaust gas, thereby enhancing a heat retaining capacity, thereby preventing particulates from being deposited.

Abstract: A gas concentration detector using solid electrolyte layers laminated measures a concentration of gas constituents in measuring gas such as exhaust gas of an internal combustion engine without being influenced by oxygen concentration in the measuring gas. The measuring gas is introduced into an inner cavity of the detector and outside air as a reference gas is introduced into an air passage in the detector. Oxygen concentration in the measuring gas in the inner cavity is maintained at a predetermined level by operation of an oxygen pumping cell constituted by an ion conductive solid electrolyte layer and a pair of electrodes formed on both surfaces of the layer. The oxygen concentration in the inner cavity is measured by an oxygen sensor cell having one electrode exposed to the inner cavity and the other electrode exposed to the reference gas.

Abstract: A battery condition detecting method is provided which includes the steps of setting a current required during standard discharge of a battery as a set current, detecting a discharge current and a voltage of the battery, determining a battery voltage when the battery discharges the set current based on the discharge current and the voltage of die battery, and projecting an actual voltage of the battery based on the battery voltage determined.

Abstract: A battery condition detecting method is provided which includes the steps of setting a current required during standard discharge of a battery as a set current, detecting a discharge current and a voltage of the battery, determining a battery voltage when the battery discharge the set current based on the discharge current and the voltage of the battery, and projecting an actual voltage of the battery based on the battery-voltage determined.

Abstract: An air-fuel ratio detecting element is composed of an oxygen pump portion and an oxygen sensor portion which are provided on a single solid electrolyte sheet, a heating element, and a spacer. The oxygen pump portion is composed of a pair first of electrodes provided on opposite sides of the solid electrolyte sheet, and a communication hole which is formed through the solid electrolyte sheet and the electrodes. Electrodes are disposed on the solid electrolyte sheet on the same side as the second electrode, whereby the oxygen sensor portion is formed. The spacer has an opening and a slit-like opening. The heating element 4, the spacer, and the solid electrolyte sheet are stacked from bottom to top, and then the stacked assembly is baked. In this case, they are stacked such that the opening faces the first electrodes and the second electrode.

Abstract: A map charging index representing discharge characteristics of a battery is obtained based on a battery voltage under a predetermined discharging operation. The map charging index indicates 100 at a first battery voltage obtainable immediately after the battery starts the discharging operation from a fully charged condition and also indicates 0 at a second battery voltage obtainable when the battery substantially ceases the discharging operation. An accumulative charging index is calculated by subtracting a charged capacity from a temporary full-charge capacity of the battery. The temporary full-charge capacity is corrected based on a difference between the map charging index and the accumulative charging index, thereby obtaining a corrected full-charge capacity. And, a dischargeable capacity of the battery is calculated by subtracting the discharged capacity from the corrected full-charge capacity.

Abstract: In an oxygen concentration detector which comprises an oxygen ion-conducting solid electrolyte, a pair of electrodes, provided on both sides of the solid electrolyte, as counterposed against each other, at least one of the electrodes being exposed to a sample gas, an oxygen ion-conducting diffusion-resistant layer, provided on the electrode exposed to the sample gas and having a predetermined porosity thereby to promote the diffusion of the sample gas, the present oxygen concentration detector is characterized by an electrically insulating porous layer, made of an electrically insulating material, provided between the electrode exposed to the sample gas and the diffusion-resistant layer and having a lower porosity than that of the diffusion-resistant layer and can accurately detect an oxygen concentration of the sample gas with current-voltage characteristics free from hysteresis.