Abstract: A BaSnO.sub.3 exhaust gas sensor and a process for producing the same. Surface reformation of sensor electrodes is done for preventing the deterioration of the sensor response and the corrosion of the electrodes by the Sn in the BaSnO.sub.3. After depositing an oxide film such as La.sub.2 Ti.sub.2 O.sub.7 or MgO on the surface of the electrodes, the electrodes are embedded in BaSnO.sub.3, and the BaSnO.sub.3 is sintered. Through the sintering process, the film of La.sub.2 Ti.sub.2 O.sub.7 or MgO is converted to a conductive complex oxide film by reacting with BaSnO.sub.3. The resultant film contains Ba and Sn elements. CaSnO.sub.3 and SrSnO.sub.3, which are homologous compounds of BaSnO.sub.3, are usable in place of BaSnO.sub.3.

Abstract: A gas detecting device includes a substrate, an insulator layer formed on the substrate, a gas sensitive layer formed the insulator layer, a pair of detection leads formed on the insulator layer, the gas sensitive layer partially overlying the pair of detection leads, a signal derived from the gas sensitive layer being sent to an external circuit through the pair of detection leads, a heater member arranged on the insulator layer in the vicinity of the gas sensitive layer, and an insulation coating layer formed on the pair of detection leads and the heater member, and partially overlying the gas sensitive layer so that the gas sensitive layer is put between the insulator layer and the insulation coating layer, and a portion of an upper surface of the gas sensitive layer is exposed to gas.

Abstract: A method of making a humidity sensor comprises providing a host device constituted by a semi-conductor substrate (10) and a gate insulator (13) of an insulated gate field effect transistor, forming a layer (14) of poly (vinyl) alcohol (PVA) on the exposed surface of the insulator, heat treating the layer to crystallize and stabilize the PVA, and forming a gate electrode (15) on the PVA layer, so that the gate electrode is porous allowing ambient water vapor to be absorbed by the PVA which, in response, undergoes a change of bulk dielectric constant, thereby causing a change in gate capacitance of the transistor resulting in a detectable change of electrical conductivity in the drain source channel.

Abstract: Chemical microsensors are fabricated by applying dithiolene transition metal complexes as thin films to chemiresistor devices using the Langmuir-Blodgett technique. The thin films interact with ambient gases and change electrical conductivity upon exposure to a particular gas or vapor. The film material determines the chemical sensitivity and selectivity. The degree of current change depends on the particular gas or vapor and its concentration. These compounds are different in structure and electrical conductive response to gas or vapors than previous materials used for chemical microsensors. This invention is particularly suited for hydrazine detection.

Abstract: Semiconductors for resistive gas sensors or resistive semiconductor gas sensors with high speed of reaction are disclosed. These semiconductors are appropriate to measure the partial pressure of oxygen and reducing gases in any predetermined measurement range between 10.sup.-30 and about 1 bar or in the whole of this measurement range, their resistance changes being caused by a volume effect. In particular, these semiconductors have a layer less than 100 .mu.m thick, predetermined geometric structure and clearly marked marginal zones. A specially doped semiconductor composed of perowskit having the general formula A'.sub.x A.sub.1-x-Z1 B'.sub.y B.sub.1-y-Z2 O.sub.3 is applied on a substrate with a paste of an organic base material by a thick film technique. By adding or removing at least one element or by using two different semiconductors the characteristic curve is clearly traced.

Abstract: A gas detecting device includes a substrate, an insulating layer supported by the substrate, first and second pairs of detection leads formed on the insulating layer, a heater lead formed on the insulating layer, the first and second pairs of detection leads being heated by passing a heater driving current through the heater lead, a gas sensitive layer formed of a gas sensitive material and provided so as to partially make contact with the first and second pairs of detection leads, and a passivation layer formed so as to cover the first and second pairs of detection leads and the heater lead. A gas detection signal is output from the gas sensitive layer through one of the first and second pairs of detection leads. A gas detecting system including the above gas detecting device is also provided.

Abstract: Excellent electrical connection between a female contact and an electrode terminal of an oxygen sensor can be assured for a long period of use even when the oxygen sensor is exposed to vibrations and/or humid atmosphere, by providing an oxygen sensor, comprising electrodes, a sensor element which generates an electromotive force or which changes its electric resistance value between the electrodes depending on oxygen concentration of a gas to be measured, electrode terminals arranged on the sensor element and connected to the electrodes, and a metallic accommodating member accommodating the sensor element, comprising; a female contact electrically connected to the electrode terminal; a ceramic housing electrically insulating the female contact from the metallic accommodating member; a resilient member pressing the ceramic housing; and a caulking ring pressing the resilient member to exhibit its resilient power; the female contact, the ceramic housing, the resilient member and the caulking ring forming a conse

Abstract: The present invention relates, a compound for use with selective detectors of the semiconductor resistance type which detect for nitrogenous reducing gases in the atmosphere, especially ammonia and gases containing NH and/or NH.sub.2 groups, said compound comprising the gallium nitride and, oxynitrides of tetrahedral structure according to the general formula: ##EQU1## in which: .quadrature. represents a hole, and 0.ltoreq.x.ltoreq.0.3.

Abstract: An oil-leakage sensor formed from a porous water-repellent resin admixed with fine electrically conductive carbon particles coated with a water-repelling layer.

Abstract: A gas sensing element, such as may be used to sense the presence of oxygen contained in the exhaust from a burner or internal combustion engine, whereby, by preventing the re-sintering of functional layers of the sensing element, a deterioration of the performance of the element under high-temperature operating conditions is prevented. The inventive sensing element includes a ceramic susbtrate, an electrode layer formed on the ceramic substrate, a first functional layer overlying the ceramic susbtrate and the electrode layer and which contains a transition metal oxide as a main component, and a second functional layer that cover the first functional layer and which contains 1 to 30 wt % of an anti-sintering agent and has a transition metal oxide as a main component.

Abstract: A ceramic heater including a ceramic body and a heater element formed on the ceramic body. The heater element has a heat-generating portion formed of a cermet containing a ceramic material and a metal material which principally consists of at least one noble metal, electrical lead portions formed of a metallic material which principally consists of at least one base metal, or formed of a cermet containing a ceramic material and said metallic material, and connecting portions connecting said heat-generating portion to said electrical lead portions.

Abstract: An oxygen sensor having construction of an upper open end portion plugged with a grommet through which lead wires are taken out of a protecting metallic cover. A resin grommet of a heat resistant resin such as Teflon, polyimide or the like is fitted in the upper open end portion of the metallic cover with a portion of the grommet being extended from upper open end portion of the metallic cover. A heat resistant non-metallic tube such as Teflon, polyimide, silicone rubber, fluororubber tube is closely fitted on the periphery of the extended portion of the resin grommet and the periphery of the upper end portion of the metallic cover and a metallic tube being closely fitted on the periphery of a portion of the non-metallic tube which is fitted on at least the metallic cover.

Abstract: A sensor comprising a metal heat generating member formed with a heat-resistant insulating coating of Al.sub.2 O.sub.3 or the like over its surface, and an atmosphere-sensitive layer of SnO.sub.2 or the like supported on the coating. The insulating coating is formed, for example, by alumina sol coating and thermal decomposition, or plasma CVD of an aluminum compound. The sensitive layer is formed, for example, by the thermal decomposition of an organic compound of tin, vacuum evaporation or sputtering of tin, or printing of SnO.sub.2 on the heat generating member when the member is in the form of a flat plate. At least one electrode is connected to the sensitive layer for deriving an output from the layer in response to a combustible gas, humidity or the like.

Abstract: A sensor having a pair of sensor units, one of which is a detecting sensor unit and the other of which is a reference sensor unit, wherein each of the units comprises a substrate with a hollow portion, a thin insulating layer with a bridge, cantilever or diaphragm shape disposed on the substrate, a sensitive film disposed on the bridge, cantilever or diaphragm portion of the thin insulating layer, and a pair of electrodes being in contact with the sensitive film, the sensitive film section of the detecting sensor unit being exposed to an atmosphere to be measured so that the electrical resistance of the sensitive film changes with a variation in the physical quantity of the atmosphere to be detected, and the sensitive film section of the reference sensor unit being sealed within a shielding container so that the electrical resistance of the sensitive film is not influenced by a variation in the physical quantity of the atmosphere outside of the container, whereby the absolute physical quantity of the atmosphe

Abstract: An apparatus comprising a chemically sensitive sensor material, having an electrical resistance or dielectric constant which changes under the effect of the gases or vapors. According to the invention, this sensor material, which comprises either hydrophobic metal complexes, or a mixture of at least one phthalide and at least one acidic compound, serves as resistance or as dielectric material. These sensor materials change their ion mobility and/or their ionic concentration under the effect of gases or vapors, thereby changing their resistance or capacitance. The change in resistance or the change in capacitance can expediently be converted into a frequency change by a multivibrator. Thus, one obtains an especially simple and very effective sensor for gases and vapors.

Abstract: The present invention is directed towards a low power, solid state gas sensor and method of making the same. The sensor comprises a heating element formed from a wire coiled about an axis, a sensing whisker placed inside the heating coil substantially in plane with said axis, and a metal oxide semiconductor material whose resistance varies with the object gas concentration. The gas sensors of this type operate at less than 150 mA. In addition, gas sensors of the present invention exhibit a substantially linear response over a significant concentration of the object gas.

Abstract: A gas sensing thick film is positioned on an insulating substrate in contact with a pair of electrodes. A non-porous glass layer surrounds the film to stabilize it on the substrate. A heating element maintains the film at a preselected elevated temperature. The gas sensing thick film has a response characteristic for a preselected target gas to be detected which is enhanced by impregnating the film with platinum or palladium chlorine free compounds. The response characteristic of the gas sensing film is further increased by promoting combustion of interference gases on an outer filter layer fabricated of either conductive or nonconductive material. The incorporation of an insulating material between the gas sensing film and the outer filter layer also serves to increase the relative response of the gas sensing film to a preselected target gas.

Abstract: A sensor for a gas detector is provided that detects the presences of the gas when the gas reacts with a distributed Rc notch network to cause a shift in operating frequency and notch depth. A metallic/metallic oxide gas sensitive discontinuous film acts as the distributive resistive element in the RC notch network. The gas changes the conductivity of the film and this causes the network to react. In the preferred embodiment, a copper/cuprous oxide film detects organophosphorus compounds.

Abstract: A gas sensor using an n-type metal oxide semiconductor and a method for manufacturing such a gas sensor is provided. More particularly, a gas sensor for detecting an inflammable gas and a method for manufacturing the same.

Abstract: A solid state thin film detection and measurement apparatus for halogen gas components such as chlorine in a gas mixture is described. The detection cell employs plural response modes to the halogen gas including response to the thermal effect of a halogen and thin film reaction and response to the thermal and ion diffusion effects of the halogen reaction with a halide supporting substrate member. These plural responses are manifested by an electrical resistance change in the thin film element and this change is sensed with a four-lead measurement arrangement. The use of plural measurement cells each of a different composition and computerized multiplexing of thin film resistance signals is included as are identification of possible thin film and substrate compositions.

Abstract: In accordance with the present invention a microdevice 10 is set forth for gas sensing. The microdevice 10 includes a conductive substrate 12 having an insulator layer 14 on a surface 16 thereof, the insulator layer 14 having an opening 18 therethrough exposing a portion 20 of the surface 16. A conducting member 22 is in contact with the insulator layer 14. The member 22, the insulator layer 14 and the portion 20 of the surface 16 define an ionization chamber 28. Gas can flow through the ionization chamber 28. A potential difference is applied between the substrate 12 and the member 22. The current flowing between the substrate 12 and the member 22 is measured. A microdevice 10 as disclosed herein uses very little power and has very high sensitivity.

Abstract: An electrolytic oxygen sensor in which the atmosphere is admitted to one side of the solid electrolyte through an air-permeable spacer through a dual concentric tube structure. Holes are formed in the inner tube to complete the air flow to the atmosphere. The small size of the holes prevent the entry of water and oil contaminants.

Abstract: A resistance ceramic heater including a ceramic substrate, and a heating element which has a resistance heat-generating portion, and electrical leads connected to the heat-generating portion for energizing the heat-generating portion to generate heat. The heat-generating portion consists of a plurality of electrically resisitive heat-generating conductors formed in parallel connection with each other and in series connection to the electrical leads, and a plurality of connecting conductors which connects the heat-generating conductors, at a plurality of connection points on each of the heat-generating conductors. The connecting points are spaced apart from each other along the length of each heat-generating conductor. An electrochemical element and an oxygen analyzer or sensor which uses the ceramic heater are also disclosed.

Abstract: Gas species are detected with a capacitor having a solid, ionic dielectric excited by an AC voltage in the ramp from 0.01-30 Hz, with an amplitude of 1-100 millivolts to allow physisorption processes and/or with an AC voltage in the same frequency range and amplitudes from 0.01-3 volts to achieve chemisorption reactions. The AC impedance of the capacitor is detected for both physisorption and chemisorption excitation to determine gas species and concentration. In chemisorption, diode like action occurs, and is detected by AC harmonic detection processes. The surface of the dielectric on which the gas is incident is overlaid with a grid or porous electrode, fabricated of inert metal or a catalyst which causes the capacitor to enable preferential adsorption by the dielectric of certain materials, to indicate the presence of certain gases. Plural capacitors, having different absorption characteristics in response to different gases facilitates detection of plural gases.

Abstract: An oil leakage sensor element is provided wherein a plurality of electrical conductors are contained within and separated from each other by a continuously porous polytetrafluoroethylene (PTFE) material containing from 15 to 40 weight percent carbon particles, the carbon particles having irregular shapes and average diameter between 10 and 30 millimicrons, at least a portion of the exterior surfaces of the carbon particles being exposed at the pore walls of the PTFE and extending into the pores. The porous PTFE material is preferably obtained by stretching an extruded, unsintered PTFE film containing the carbon particles, after removal of lubricant, to a draw ratio of 1.5 times or less. The sensor element, in use, is connected between electrodes which, in turn, are connected to an alarm device. Preferably, the sensor is connected to elongate conductors (wires) such that the direction of stretch of the material is aligned with the lengthwise direction of the conductors.

Abstract: A laminar gas-sensitive thick film consisting of ceramic semiconductor and metallic catalyzer is formed across a pair of electrodes carried by a ceramic substrate, and the nature of metallic catalyzer on an outer surface layer of the thick film is different from that of metallic catalyzer in that portion of the thick film which is in the proximity of the electrodes.

Abstract: An electrical sensor and sensor material for detecting the presence of an organic liquid by contact that is not sensitive to the presence of organic vapors from the liquid. The sensor material includes a relatively large concentration of electrically conductive particles within a swellable matrix.

Abstract: An alcohol selective gas sensor including a detecting electrode and a semiconductor detecting element in contact with the detecting electrode, the semiconductor detecting element comprising tin oxide (SnO.sub.2) and a metal oxide of at least one of alkaline earth metals (Be, Mg, Ca, Sr, Ba) carried by the tin oxide, the metal oxide being contained in an amount of about 0.5 mol % or above.

Abstract: An air/fuel ratio sensor has a porous alumina substrate, a limiting current type oxygen detecting section on the porous alumina substrate for detecting the air/fuel ratio in the fuel lean region, a resistance-variable type oxygen detecting section on the porous alumina substrate for detecting the excess air ratio .lambda. when .lambda. is equal to one, a gas decomposition type hydrogen detecting section on the porous alumina substrate for detecting the air/fuel ratio in the fuel rich region and a heater for heating the respective detecting sections to the optimum temperature in operation, whereby the sensor can detect the air/fuel ratio over all the fuel rich and lean regions.

Abstract: Temperature responsive apparatus includes a housing having a pair of spaced-apart probes, each receiving a different thermistor. The housing includes a one-piece hollow plastic shell having the pair of spaced apart probes formed integral therewith. The entire hollow interior of the shell, including the probes, is filled with plastic material to encapsulate the thermistors received within the probes.

Abstract: An element for detecting internal faults in an insulating gas charged electrical apparatus comprises a substrate disposed in the electrical apparatus charged with an insulating gas, a pair of electrodes disposed on the substrate, and a thin metal film covering the pair of electrodes and the exposed surface of the substrate. This film is capable of producing fluorides with low conductivity upon reacting with a decomposed gas produced by internal faults of the electrical apparatus. Since the thin metal film exhibits high response characteristics readily in reaction with even a trace amount of a decomposed gas, it is possible to promptly detect faults occurring in the electrical apparatus, such as a partial discharge or local heating. In addition, a device for detecting internal faults in an insulating gas charge electrical apparatus using the internal fault detection element utilizes an optical signal for transmitting signals.

Abstract: A gas sensor comprises a photovoltaic cell which, upon exposure to light, develops a photovoltage or photocurrent which varies as a function of the type of gas sorbed. The cell includes in order a conductor, an N-type light-absorbing semiconductor, and a thin light-transmitting gas-absorbing metal Schottky layer having electrical properties which vary with the type of gas sorbed therein.

Abstract: An apparatus and a method is provided for determining the equilibrium of the partial pressures of two gases having different thermal conductivities. The apparatus includes a single sensor adapter to be contacted by the two gases, and heated by a flow of electrical current through the sensor. A circuit is provided for maintaining the sensor at a constant level of electrical resistance and hence at a constant temperature. The sensor, in addition, is connected as one leg of a bridge circuit, the output of which represents changes occurring in the thermal conductivity of a mixture of the gases.

Abstract: To retain a plate-like sensing element, for example made of ceramic, in position within a metallic housing without danger of breakage or loosening under conditions of vibrations or shock or wide swings of temperature and substantial temperature gradients, a metallic housing has a longitudinal opening wherein in which two sealing elements are located, for example made of aluminum oxide. The sealing elements are formed, each, with an internal pocket, for example extending conically outwardly towards their meeting surfaces, to form a chamber. The chamber is filled with a resiliently compressible powder or pulverized material, for example talcum, and separates the elements by a gap (31) extending outwardly to the walls of the metallic housing. The sensor element is passed through slits formed in the end regions of the sealing elements (26, 27) and is retained in position by the compressible powder or pulverized material.

Abstract: An exhaust gas sensor in which a metal oxide semiconductor containing at least one member of a group of elements consisting of Sn, Fe, Ni and Co and Pt electrodes having ZrO.sub.2, deposited in the grain boundary are used. Such metal oxide semiconductors include, for example, SnO.sub.2, BaSnO.sub.2, BaSnO.sub.3, SrSnO.sub.3, and CaSnO.sub.3. The exhaust gas sensors are manufactured by mixing such compounds as BaCO.sub.3, SrCO.sub.3 or CaCO.sub.3 with SnO.sub.2 in equimolar ratio to react them in air at 1200.degree. C. for four hours. The compounds thus obtained were pulverized and Pt electrodes with ZrO.sub.2 were imbedded therein, then were molded into sensor chips. The chips thus molded were baked by heating in air. After the chip has been sintered the exhaust gas sensor was assembled. It comprised an insulating substrate of alumina, etc. having a recess provided at one end thereof in which the aforementioned sensor chip was housed.

Abstract: Gas species are detected with a capacitor having a solid, ionic dielectric excited by an AC voltage in the range from 0.01-30 Hz, with an amplitude of 1-100 millivolts to allow physisorption processes and/or with an AC voltage in the same frequency range and amplitudes from 0.01-3 volts to achieve chemisorption reactions. The AC impedancae of the capacitor is detected for both physisorption and chemisorption excitation to determine gas species and concentration. In chemisorption, diode like action occurs, and is detected by AC harmonic detection processes. The surface of the dielectric on which the gas is incident is overlaid with a grid or porous electrode, fabricated of inert metal or a catalyst which causes the capacitor to enable preferential adsorption by the dielectric of certain materials, to indicate the presence of certain gases. Plural capacitors, having different adsorption characteristics in response to different gases facilitates detection of plural gases.

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 moisture sensor which includes a moisture sensitive material and electrodes in communication with the moisture sensitive material, the moisture sensitive material containing a substantially electrically insulating substance derived from a colloidal dispersion and, distributed in or on the substance, an electrically conducting substance.

Abstract: A moisture sensitive material prepared by cross-linking cellulose acetate through at least one selected from the group consisting of compounds containing two or more isocyanate groups; compounds containing two or more epoxy groups; compounds containing two or more carboxyl groups ##STR1## and acid anhydrides of carboxylic acids.

Abstract: A first layer of titanium or tin is vapor deposited upon opposing major surfaces on the ceramic sensor. A second layer consisting of platinum, palladium or ruthenium is deposited over the first layer. The structure is then preferably annealed in air in order to crystallize the external layer to roughen the exterior surface and enhance adhesion. Lead wires, preferably made of Nichrome, are attached to the opposing surfaces by applying a conductive paste to the wire and surface functions, and firing the structure. The conductive paste provides a relatively low resistance, strong, mechanical bond between the lead wires and the roughened external surfaces of the structure. The first layer facilitates bonding of the second layer to the ceramic. The first and second layers cooperate to protect the ceramic from the potentially harmful glass frit contained in the conductive paste.

Abstract: A thermo-electrically regulated adsorptive sensing device comprising a gas adsorptive sensing element having a stratum of adsorbently sensitive particles, a thermistor for sensing the temperature of the sensing element, a thermo-electric module for controlled cooling and heating of the sensing element, a heat sink, and a controller unit for applying variable amounts of electrical current through the thermo-electric module to appropriately heat or cool the sensing element in a rapid, controlled and accurate fashion. The thermo-electric module may be operated either to maintain the stratum of particles of the sensing element within about 1.degree. (0.6.degree. C.) of the optimal sensing temperature or operated to heat the particles in a controlled fashion to a relatively high purging temperature at which the gas is relatively rapidly desorbed, and then cool the particles in a controlled fashion to a relatively lower sensing temperature at which the gas is relatively rapidly adsorbed by the particles.

Abstract: An air-fuel ratio sensor including a box member having a wall made of oxygen ion-conductive electrolyte having a pair of porous electrodes on opposite sides and a diffusion-limiting portion providing communication between the inside and outside of the box member, and an oxygen gas sensing element formed within the box member by injection and firing. The oxygen gas sensing element has a resistance which varies in accordance with the oxygen partial pressure of the atmosphere in which the sensor is immersed.

Abstract: Combustible gas detecting element for detecting the existence of combustible gas such as methane, ethane, propane iso-butane and hydrogen. The element comprises .alpha.-Fe.sub.2 O.sub.3 containing a small amount of sulfate ion (SO.sub.4.sup.--). By using a precipitation process with urea as a precipitant for preparing the above .alpha.-Fe.sub.2 O.sub.3, remarkably high stability and reliability can be released. Addition of quadrivalent metal of Sn, Zr or Ti to the .alpha.-Fe.sub.2 O.sub.3 greatly enhances the gas sensitivity to those gases. Furthermore the sensitivity to carbon monoxide was also enhanced by adding cadmium (Cd) and/or gold (Au).

Abstract: A gas sensor in which a compound of rhenium is added to tin oxide (SnO.sub.2). Rhenium inhibits the sensor from lowering its resistance over time and in particular increases its durability against overheating. Rhenium is preferably used together with vanadium. Rhenium is preferably added by impregnation in order to maintain temperature characteristic of the sensor.

Abstract: A gas sensor element comprising a film of a semiconducting compound of formula I supported by a non-conductive substrate, the film being disposed between conductors for supplying a current to the film and withdrawing a current therefrom. ##STR1## in which: M represents 2H, Mn, Fe, Co, Ni, Cu, Hg, Cd, Pb, Pt or Pd;R.sub.1 represents H, CH.sub.3, Cl, Br, I, CN, CO.sub.2 H, COOC.sub.n H.sub.2n+1, CONH.sub.2 or NO.sub.2 ;R.sub.2 represents H or CH.sub.3 ; andR.sub.3.sup.a and R.sub.3.sup.b, which may be identical or different represent H, NO.sub.2, Cl, CO.sub.2 H or CH.sub.3 ;provided that when M represents cobalt at least one of R.sub.1, R.sub.2, R.sub.3.sup.a and R.sub.3.sup.b is other than hydrogen.

Abstract: A Sensor for measuring oxygen partial pressures in hot gases includes a semiconducting nonstoichiometric oxide material in the form of a solid solution in uranium dioxide UO.sub.2 of at least one other metal oxide having an oxygen/metal (O/M) ratio of less than two and a uranium/other metal (U/M) ratio such that the material has n-type conductivity. The sensor further includes at least one pair of electrodes contacting the nonstoichiometric oxide material at spaced apart locations for connection to a device for determining the resistance of the material between the electrodes.

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: A gas sensor includes a pair of electrodes printed on an electrically insulating substrate, a sensitive layer deposited on tip portions of the electrodes and a part of the substrate adjacent to the tip portions and bridging the space between the electrodes at the tip portion, and a protective film deposited on the electrodes and a part of the substrate adjacent to the tip portion so that a part of each electrode covered with the sensitive layer is free of the protective film. The sensitive layer is formed by depositing titanium oxide by plasma spraying on the substrate, and then heat-treating the deposited titanium oxide, so as to provide a diffusion reactive layer between the sensitive layer and the substrate and to form fine grooves on the surface of the sensitive layer.

Abstract: A gaseous composition sensor which is a microstructure device comprising a heated planar thin film diaphragm sensor member suspended over a shallow flat bottomed etched pit in a single crystal silicon substrate.

Abstract: A catalytic-combustion sensor has a rigid support having a flat support face, a metallic resistance-type heater film flatly adhered to the support face, and a catalyst film flatly adhered in heat-transmitting connection to the heater film. The heater element is made of platinum or gold and the catalyst film is made of a platinum-group compound such as a palladium-, platinum, rhodium-, or iridium-compound, in an arrangement used to detect methane, although different materials can be used for other gases such as propane or butane. Normally a diffusion-blocking layer overlies the catalyst film. The heater film is a strip following a nonstraight, normally meandering, path on the support face and support is a rigid bar having a back face opposite to the support face and formed thereon in registration with the nonstraight heater film with a rearwardly open groove that reduces the thickness of the bar at the heater film.