JP2012008130A - Analyzer of mixture of gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical sensor array and a method capable of directly detecting nitrogen oxide, hydrocarbon, carbon monoxide, oxygen or the like contained in a multicomponent gas system such as combustion process exhaust gas.SOLUTION: (i) The chemical sensor array is constituted by including processes of: exposing the chemical sensor including at least two arrays of chemical/electroactive materials to the multicomponent gas system; detecting responses; and directly measuring the responses of each chemical/electroactive material. The chemical/electroactive materials are semiconductor materials. The responses to be measured are capacitance, voltage, current, an AC impedance or a DC resistance value.

Description

The present invention is a method and apparatus for the detection and analysis of certain gases, including NO _x , hydrocarbons, carbon monoxide and oxygen in multicomponent gas systems using chemical sensors and chemical sensor arrays. Sensors and sensor arrays use chemically / electroactive materials to detect the presence of individual gases and / or calculate concentrations in a multi-component gas system.

  The use of chemical sensing devices for detecting certain gases is known. Numerous attempts have been made to find materials with selectivity and sensitivity for certain gases. For example, Patent Document 1 discloses a resistance sensor for measuring oxygen. See also Non-Patent Document 1. Obviously, a different material must be used for each gas to be detected. However, if the gas is part of a multi-component system, it is difficult to detect one particular gas using one material due to the cross-sensitivity of the material to the various component gases of the mixture.

An example of a multi-component gas system is flue gas that may contain oxygen, carbon monoxide, nitrogen oxides, hydrocarbons, CO ₂ , H ₂ S, sulfur dioxide, hydrogen, water vapor, halogen and ammonia. See Non-Patent Document 2. In many combustion processes, there is a need to determine whether the exhaust gas meets the requirements established by federal and state air quality regulations in various jurisdictions. Several types of gas sensors have been developed to address this need. Friese et al., Which discloses an electrochemical oxygen sensor, U.S. Pat. No. 6,057,059, Noda et al., U.S. Pat. See U.S. Pat. No. 6,057,089 which discloses a resistance sensor for measuring. For example, two or more of a mixture such as flue gas from the point of data only caused by direct contact with a gas sensor and without having to separate any of the gases in the mixture It would be advantageous to be able to analyze the components simultaneously and calculate the concentration. Prior art methods currently do not meet this need.

  A number of sensors have been disclosed for detecting gases generated from food and from other relatively cold applications. See Non-Patent Document 3. Several arrays of undoped and doped tin oxide sensors have also been disclosed for use in the detection of various combustion gases below 450 ° C. See Non-Patent Document 4, Non-Patent Document 5, and Non-Patent Document 6. However, at higher temperatures and in highly corrosive environments that use chemical sensors to monitor combustion gases, the operating temperature can alter or impair the performance of the sensor array. In such cases, the high temperature environment requires the use of materials that are both chemically and thermally stable and that maintain a measurable response to the gas. The influence of operating temperature on the response of tin oxide based sensor arrays was studied below 450 ° C. See Non-Patent Document 6. However, in addition to what is known in the art so far, the material is capable of directly monitoring the exhaust gases of a multi-component gas system at higher temperatures, as would be encountered in the operation of a combustion gas system, and There is still a need to be able to provide a device.

US Pat. No. 4,535,316 US Pat. No. 5,630,920 U.S. Pat. No. 4,770,760 US Pat. No. 4,535,316

Etch. H. Meixner et al., Sensors and Actuators, B33 (1996) pp. 198-202. Etch. Makesner et al., Fresenius, J.M. Anal. Chem. 348 (1994) 536-541 Kay. K. Albert et al., Chemical Review (Chem. Rev.), 200 (2000) 2595-2626. Sea. C. Di Natal et al., Sensors and Actuators, B20 (1994) pp. 217-224 Je. J. Getino et al., Sensors and Actuators, B33 (1996) pages 128-133. Sea. Jintale et al., Sensors and Actuators, B23 (1995) pp. 187-191

  Addressing this need would allow the use of chemical sensors to measure flue gases, such as automotive exhaust, and determine whether those exhausts meet functional and mandatory requirements. In addition, it has also been surprisingly found that the method and apparatus of the present invention that are useful for analyzing hot gases such as automotive exhaust gas may be used with equal efficacy in the analysis of cold gases.

  The present invention is a method for direct detection of a gas component in a multi-component gas system, comprising: (i) exposing a chemical sensor comprising an array of at least two chemically / electroactive materials to the multi-component gas system; A method is provided comprising the steps of detecting a response and directly measuring the response of each chemically / electroactive material. Preferably the chemical / electroactive material is a semiconductor material and the multi-component gas system is a combustion process exhaust gas. The measured response can be a measurement of capacitance, voltage, current, AC impedance, or DC resistance.

  The present invention is also a chemical sensor for directly detecting the presence of a gas component in a multi-component gas system comprising a substrate, an array of at least two chemically / electroactive materials on the substrate, And a means for detecting a response from the chemically / electroactive material when exposed to the analyte gas component. Preferably the chemical / electroactive material is a semiconductor material and the multi-component gas system is a combustion process exhaust gas. The detected response can be an electrical characteristic such as capacitance, voltage, current, AC impedance, or DC resistance. The device can further include a housing, means for measuring the detected response, and means for analyzing the result of the measured response to identify the presence and / or concentration of the analyte gas component. .

  The present invention also provides a chemical sensor device for directly detecting the presence and / or concentration of a gas component in a multi-component gas system comprising a substrate and at least two chemical / electrical electrodes deposited on the substrate. To identify an array of active materials, means for detecting changes in the electrical properties of the chemically / electroactive material upon exposure to the multi-component gas component, and the presence and / or concentration of the gas component There is also provided a device comprising means for analyzing the result of the detected change in electrical properties and a housing. The chemically / electroactive material may be a semiconductor material.

Another embodiment of the present invention is a gas detection device comprising an array of at least three chemically / electroactive materials, wherein each chemically / electroactive material exhibits a change in electrical resistance upon exposure to a multi-component gas mixture, And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; b) A device that exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to the gas mixture as compared to the resistance before exposure. Yet another embodiment of the present invention provides a multicomponent gas mixture comprising an array as described above and a means for measuring the electrical response of the chemically / electroactive material upon exposure of the array to the gas mixture. It is an analysis device.

  Yet another embodiment of the present invention exhibits electrical response characteristics that differ from each of the other chemically / electroactive materials when each chemically / electroactive material is exposed to the multi-component gas mixture at a selected temperature, A gas detection device comprising an array of at least two chemically / electroactive materials, wherein the electrical response characteristic of at least one material can be quantified as a value, the response value of the material being at least about 1 at a selected temperature. A device that is constant or varies by no more than about 20 percent during exposure of the material to the gas mixture for a period of minutes. Yet another embodiment of the present invention provides a multicomponent gas mixture comprising an array as described above and a means for measuring the electrical response of the chemically / electroactive material upon exposure of the array to the gas mixture. It is an analysis device.

Yet another embodiment of the invention is that each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to a multi-component gas mixture at a selected temperature. The array of chemical / electroactive materials shown, wherein at least one chemical / electroactive material is M ¹ O _x , M ¹ _a M ² _b O _x and M ¹ _a M ² _b M ³ _c O _x , where M ¹ is selected from the group consisting of Ce, Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independent Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, Sc, Si, Sn, Sr, Ta, Ti, T selected from the group consisting of m, V, W, Y, Yb, Zn, and Zr, but M ² and M ³ are not the same in M ¹ _a M ² _b M ³ _c O _x , a, b and each c is independently from about 0.0005 to about 1, and x is a number sufficient to balance the oxygen present with the charge of other elements in the compound. An array. Yet another embodiment of the present invention provides a multicomponent gas mixture comprising an array as described above and a means for measuring the electrical response of the chemically / electroactive material upon exposure of the array to the gas mixture. It is an analysis device.

Yet another embodiment of the invention is that each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the multi-component gas mixture at a selected temperature. A gas detection device comprising an array of first and second chemical / electroactive materials, wherein the chemical / electroactive material is (i) the first material is M ¹ O _x and the second material is M ¹ _a M ^2. _b O _x ,
(Ii) The first material is M ¹ O _x and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iii) The first material is M ¹ _a M ² _b O _x and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iv) the first material is first M ¹ O _x and the second material is second M ¹ O _x ;
(V) the first material is the first M ¹ _a M ² _b O _x , the second material is the second M ¹ _a M ² _b O _x , and (vi) the first material is the first M ¹ _a M ² _b M ³ _c O _x and the second material is the second M ¹ _a M ² _b M ³ _c O _x (where M ¹ is Ce, Co, Cu, Fe, Ga) , Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb
, Sc, Si, Sn, Sr, Ta, Ti, Tm, V, W, Y, Yb, Zn, and Zr, but M ² and M ³ are M ¹ _a M ² _b M ³ _c O _x is not the same, a, b and c are each independently about 0.0005 to about 1, and x is used to balance the oxygen present with the charge of other elements in the compound. Enough)
A device selected from pairing in the group consisting of: Yet another embodiment of the present invention provides a multicomponent gas mixture comprising an array as described above and a means for measuring the electrical response of the chemically / electroactive material upon exposure of the array to the gas mixture. It is an analysis device.

  Yet another embodiment of the present invention provides: (a) at least two chemistries where each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the gas mixture. A multi-component gas mixture analyzer comprising: an array of electroactive materials; and (b) means for individually measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture. The apparatus may also optionally include means for measuring the temperature of the array and means for digitizing the electrical response and temperature measurements.

  Yet another embodiment of the present invention is a device for calculating the concentration of at least two individual analyte gas components in a multi-component gas mixture, wherein (a) each chemically / electroactive material is exposed to the gas mixture. Sometimes an array of at least three chemically / electroactive materials that exhibit different electrical response characteristics than each of the other chemically / electroactive materials, and (b) exposure of the array to only unseparated components of the gas mixture An apparatus that sometimes includes means for measuring the electrical response of each chemical / electroactive material and (c) means for calculating the concentration of individual analyte gas components from the electrical response of the chemical / electroactive material. is there.

  Yet another embodiment of the present invention provides that (a) each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture. An array of chemically / electroactive materials; (b) means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture; and (c) (i) at least two of the first group. Detecting the presence of a subgroup of gases in the mixture from the responses of two chemically / electroactive materials, and (ii) the presence of individual component gases in the mixture from the responses of at least two chemically / electroactive materials of the second group And an analysis device for a multi-component gas mixture.

Yet another embodiment of the present invention provides:
(A) providing an array of at least two chemically / electroactive materials wherein each chemically / electroactive material exhibits an electrical response different from each other chemically / electroactive material upon exposure to a gas mixture;
(B) exposing the array to a gas mixture;
(C) measuring the electrical response of each chemically / electroactive material individually upon exposure of the array to the gas mixture;
(D) measuring the temperature of the gas mixture independently of measuring the electrical response of the chemically / electroactive material;
(E) digitizing electrical response and temperature measurements, and including a method for analyzing a multi-component gas mixture.

Yet another embodiment of the present invention provides:
(A) an array of at least three chemically / electroactive materials, wherein each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture, comprising at least When one chemically / electroactive material is at a temperature of about 400 ° C. or higher, (i) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm, and (ii) Providing an array in the gas mixture that exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to the gas mixture as compared to the pre-exposure resistance;
(B) measuring the electrical response of each chemically / electroactive material upon exposure of the array to unseparated components of the gas mixture;
(C) calculating the respective concentrations of the individual analyte gas components from the electrical response of the chemically / electroactive material, and at least two different components in the multicomponent gas mixture having a temperature of about 400 ° C. or higher. Includes a method for calculating the concentration of individual analyte gas components.

Yet another embodiment of the present invention provides:
(A) Each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture at a selected temperature, and the electrical response characteristics of at least one material An array of at least two chemically / electroactive materials that can be quantified as a value, wherein the value of the response of the material is exposed to the gas mixture for a period of at least about 1 minute at a selected temperature Providing an array that is constant or varies by no more than about 20 percent;
(B) measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture.

  Yet another embodiment of the present invention provides that (a) each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture. Providing an array of chemically / electroactive materials; (b) measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture; (c) (i) a first group of The presence of subgroup gases in the mixture from the response of at least two chemically / electroactive materials, and (ii) the presence of individual component gases in the mixture from the responses of at least two chemically / electroactive materials in the second group. This is a method for analyzing a multi-component gas mixture by a detecting step.

Draw an array of chemically / electroactive materials. FIG. 6 is a schematic illustration of a pattern of interdigitated electrodes overlaid with a dielectric top layer that forms sixteen wells in an array of chemically / electroactive materials. Depicts electrode patterns, dielectric patterns, and sensor material patterns in an array of chemically / electroactive materials.

  The present invention is a method and apparatus for direct detection of one or more analyte gases in a multi-component gas system under variable temperature conditions. “Direct sensing” means being exposed to a mixture of gases that make up a multi-component gas system, such as in a gas stream through which an array of gas sensing materials flows. The array may be placed in the gas mixture, more particularly in the source of the gas mixture, if necessary. Alternatively, the array may be in a chamber where the gas mixture is directed from its source elsewhere. When gas is directed into the chamber in which the array is located, the gas mixture may be placed into and removed from the chamber by piping, conduits or other suitable gas transfer device.

A response may be obtained upon exposure of the gas sensing material to the multi-component gas mixture, which response will be a function of one or more concentrations of the analyte gas itself in the gas mixture. The sensor material will be exposed to each of the analyte gases at substantially the same time, and the analyte gas is physically removed from the multi-component gas mixture for analysis of the mixture to be performed and / or one or more components thereof. It doesn't have to be separated. The present invention can be used for example for hydrocarbons such as oxygen, carbon monoxide, nitrogen oxides, butane, CO ₂ , H ₂ S, sulfur dioxide, halogens, hydrogen, water vapor and ammonia at variable temperatures in automotive exhaust. Can be used to detect and / or measure the concentration of combustion gases.

  The present invention is therefore useful at higher temperatures found in automotive exhaust systems, typically in the range of about 400 ° C to about 1000 ° C. In addition, there are various other combustion processes to which the present invention may be applied, including diesel engines and home heating. These applications typically require the detection of gases such as nitrogen oxides, ammonia, carbon monoxide, hydrocarbons and oxygen at ppm to percent levels in highly corrosive environments. The present invention may also be used in other gas systems such as those found in manufacturing processes, waste streams, and environmental monitoring, or in systems where odor detection is important and / or in the medical, agricultural or food and beverage industries. It is also useful for detecting gases in systems at lower temperatures.

  The present invention utilizes an array of sensing materials to analyze the gas mixture and / or its components, eg, detecting the presence of one or more individual analyte gas components in the system, and / or Calculate their concentration. “Array” means at least two different materials that are spatially separated, for example as shown in FIG. The array may include, for example, 3, 4, 5, 6, 8, 10, or 12 gas sensing materials, or other larger or smaller numbers of gas sensing materials as desired. Preferably, at least one sensor material is provided for each individual gas or subgroup in the mixture to be analyzed. However, it may be desirable to provide more than one sensor material that responds to individual gas components and / or certain subgroups in the mixture. For example, a group of at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 sensors, one or more individual component gases in the mixture and / or one or more It could be used to detect the presence of these subgroups of gases and / or calculate their concentrations. A different group of sensors, which may or may not have components in common, could be used for this purpose. A sub-group gas that is an analyte as a sub-group may or may not contain an individual gas that is itself an analyte as a component. Preferably, the molar percentage of the main component of each gas sensing material is different from the others.

  The sensing material used is a chemically / electroactive material. A “chemical / electroactive material” is a material that has an electrical response to at least one individual gas in a mixture. Some metal oxide semiconductor materials, mixtures thereof, or mixtures of metal oxide semiconductors with other inorganic compounds are chemically / electroactive and are particularly useful in the present invention. Each of the various chemically / electroactive materials used herein is preferably of a different type and / or degree than each of the other chemically / electroactive materials upon exposure to the mixture and / or analyte gas. Shows an electrically detectable response. As a result, an appropriately selected array of chemically / electroactive materials can interact with the analyte gas, detect the analyte gas, or in the mixture, despite the presence in it of interfering gases of no interest. Can be used to analyze multi-component gas mixtures, such as by measuring the presence and / or concentration of one or more analyte gases.

The present invention is useful for detecting those gases that are expected to be present in a gas stream. For example, gases expected to be present in the combustion process include oxygen, nitrogen oxides (such as NO, NO ₂ , N ₂ O or N ₂ O ₄ ), carbon monoxide, hydrocarbons (C _n H _{2n + 2} And also saturated or unsaturated, or optionally substituted with heteroatoms, such as its cyclic or aromatic analogs), ammonia or hydrogen sulfide, Sulfur, CO ₂ or methanol is included. Other such gases include alcohol vapors, solvent vapors, hydrogen, water vapor, those derived from saturated and unsaturated hydrocarbons, ethers, ketones, aldehydes, carbonyls, biomolecules and microorganisms. The component of the multi-component gas mixture as the analyte may be an individual gas such as carbon monoxide or some of a subgroup, such as nitrogen oxide (NO _x ). , Not all of the gases contained in the mixture, or a combination of one or more individual gases and one or more subgroups. If the sub-group gas is an analyte, the chemical / electroactive material will respond to the overall concentration within the multi-component gas mixture of the combined sub-group components.

  Obtaining information related to the composition content of the gas mixture using these sensor materials, such as gas concentration measurements, can be obtained upon exposure of the material to a mixture containing one or more analyte gases. It can be based on a change in electrical properties, such as at least one, but preferably each and every AC impedance. Analysis of the gas mixture can also be done with respect to the degree of change in other electrical properties of the sensor material, such as capacitance, voltage, current or AC or DC resistance. The change in DC resistance may be measured, for example, by measuring the change in temperature at a constant voltage. One change in these exemplary properties of the sensor material is a function of the partial pressure of the analyte gas in the gas mixture, which in turn determines the concentration at which analyte gas molecules will be adsorbed onto the surface of the sensor material. Thus, this affects the electrical response characteristics of the material. By using an array of chemically / electroactive materials, at least one in a multi-component gas system with a respective response pattern exhibited by the material upon exposure to a mixture containing one or more analyte gases. The presence of the species gas can be detected simultaneously and directly and / or its concentration can be measured simultaneously and directly. The present invention can now be used to measure the composition of a gas system. This concept is illustrated schematically in FIG. 1 and illustrated below.

  To illustrate, consider the theoretical example below for exposure of sensor material to a mixture containing analyte gas. If a response is obtained, the event is represented as a plus (+), and if no response is obtained, the event is represented as a minus (-). Material 1 responds to gas 1 and gas 2 but does not show any response to gas 3. Material 2 responds to gas 1 and gas 3 but does not show any response to gas 2 and material 3 responds to gas 2 and gas 3 but does not show any response to gas 1.

  Therefore, if an array of materials 1, 2 and 3 gives the following response to an unknown gas:

The unknown gas will then be identified as gas 2. The response of each sensor material is a function of the partial pressure within the mixture of analyte gases, and hence its concentration or the total concentration of subgroup analyte gases, and the response is quantified or recorded as a processable value, such as a numerical value. I can do it. In such cases, one or more response values can be used to generate quantitative information regarding the concentration in the mixture of one or more analyte gases. In multi-component gas systems, chemometrics, neural networks or other pattern recognition methods can be used to calculate the concentration of one or more gases in the mixture of the system.

Although the chemical / electroactive material can be of any type, semiconductor metal oxides such as ZnO, TiO ₂ , WO ₃ , and SnO ₂ are particularly useful. These specific materials are advantageous because of their chemical and thermal stability. The chemically / electroactive material can be a mixture of two or more semiconductor materials, or a mixture of semiconductor materials with inorganic materials, or combinations thereof. The semiconductor material is an insulator, such as but not limited to alumina or silica, and can be deposited on a suitable solid substrate that is stable under the conditions of a multi-component gas mixture. The array then takes the form of a sensor material as it is deposited on the substrate. Other suitable sensor materials include bulk or thin film type single or polycrystalline semiconductors, amorphous semiconductor materials, and semiconductor materials that are not made of metal oxides.

Chemical / electroactive materials used as sensor materials in the present invention are, for example, the formula M ¹ O _x , M ¹ _a M ² _b O _x , or M ¹ _a M ² _b M ³ _c O _x.
(Where
M ¹ , M ² and M ³ are metals that form stable oxides when fired above 500 ° C. in the presence of oxygen;
M ¹ is selected from groups 2-15 of the periodic table and lanthanides
M ² and M ³ are independently selected from groups 1-15 and lanthanide of the periodic table, but M ² and M ³ are not the same in M ¹ _a M ² _b M ³ _c O _x ,
a, b, and c are each independently in the range of about 0.0005 to about 1, and
x is a number sufficient to balance the oxygen present with the charge of other elements in the compound)
Or a mixture thereof.

A metal oxide containing two or more metals does not have to be a compound or a solid solution, but can be a mixture of individual metal oxides. They may exhibit a compositional gradient and may be crystalline or amorphous. Suitable metal oxides are
1) A resistance of from about 1 to about 10 ⁶ ohm-cm, preferably from about 1 to about 10 ⁵ ohm-cm, more preferably from about 10 to about 10 ⁴ ohm-cm when at a temperature of about 400 ° C. or higher. Having a rate,
2) one that exhibits a chemical / electrical response to at least one gas of interest, and 3) one that is stable and has mechanical integrity, i.e. can be bonded to a substrate and is in operation. It does not decompose at temperature. The metal oxide may also contain minor or minor amounts of hydration and elements present in the precursor material.

In some preferred embodiments, the metal oxide material includes:
M ¹ is selected from the group consisting of Ce, Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and / or M ² and M ³ Are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr , Rb, Ru, Sb, Sc, Si, Sn, Sr, Ta, Ti, Tm, V, W, Y, Yb, Zn, and Zr, but M ² and M ³ are M ¹ _a M ² _b M ³ _c O _x may not be the same.

In some other preferred embodiments, the metal oxide includes
M ¹ O _x is Ce _a O _x , CoO _x , CuO _x , FeO _x , GaO _x , NbO _x , NiO _{x
, PrO x, RuO x, SnO} x, Ta a O x, TiO x, TmO x, WO x, YbO x, ZnO x, ZrO x, Ag added Monoiri _SnO x, Ag added Monoiri _ZnO x, Pt added Monoiri TiO _x ZnO _x with frit additive, NiO _x with frit additive, SnO _x with frit additive, or WO _x with frit additive, and / or M ¹ _a M ² _b O _x is Al _a Cr _b O _x , Al _a Fe _{b O x, Al a Mg b} O x, Al a Ni b O x, Al a Ti b O x, Al a V b O x, Ba a Cu b O x, Ba a Sn b O x, Ba a Zn b _{O x, Bi a Ru b O} x, Bi a Sn b O x, Bi a Zn b O x, Ca a Sn b O x, Ca a Zn b O x, C _{d a Sn b O x, Cd} a Zn b O x, Ce a Fe b O x, Ce a Nb b O x, Ce a Ti b O x, Ce a V b O x, Co a Cu b O x, Co _{a Ge b O x, Co a} La b O x, Co a Mg b O x, Co a Nb b O x, Co a Pb b O x, Co a Sn b O x, Co a V b O x, Co a _{W b O x, Co a Zn} b O x, Cr a Cu b O x, Cr a La b O x, Cr a Mn b O x, Cr a Ni b O x, Cr a Si b O x, Cr a Ti _{b O x, Cr a Y b} O x, Cr a Zn b O x, Cu a Fe b O x, Cu a Ga b O x, Cu a La b O x, Cu a Na b O x, Cu a Ni b _{O x, Cu a Pb b O} x, Cu a Sn b O _{x, Cu a Sr b O x} , Cu a Ti b O x, Cu a Zn b O x, Cu a Zr b O x, Fe a Ga b O x, Fe a La b O x, Fe a Mo b O x _{, Fe a Nb b O x,} Fe a Ni b O x, Fe a Sn b O x, Fe a Ti b O x, Fe a W b O x, Fe a Zn b O x, Fe a Zr b O x, _{Ga a La b O x, Ga} a Sn b O x, Ge a Nb b O x, Ge a Ti b O x, In a Sn b O x, K a Nb b O x, Mn a Nb b O x, Mn _{a Sn b O x, Mn a} Ti b O x, Mn a Y b O x, Mn a Zn b O x, Mo a Pb b O x, Mo a Rb b O x, Mo a Sn b O x, Mo a _{Ti b O x, Mo a Zn} b O x, Nb a _{Ni b O x, Nb a Ni} b O x, Nb a Sr b O x, Nb a Ti b O x, Nb a W b O x, Nb a Zr b O x, Ni a Si b O x, Ni a Sn _{bO x} , Ni _a Y _b O _x , Ni _a Zn _b O _x , Ni _a Zr _b O _x , Pb _a Sn _b O _x , Pb _a Zn _b O _x , Rb _a W _b O _x , Ru _a Sn _{b O x, Ru a W b O} x, Ru a Zn b O x, Sb a Sn b O x, Sb a Zn b O x, Sc a Zr b O x, Si a Sn b O x, Si a Ti b O _x , Si _a W _b O _x , Si _a Zn _b O _x , Sn _a Tab _b O _x , Sn _a Ti _b O _x , Sn _a W _b O _x , Sn _a Zn _b O _x , Sn _a Zr _b O _x , Sr _a Ti _b O _x , Ta _a Ti _b O _x , Ta _{a Zn b O x, Ta a} Zr b O x, Ti a V b O x, Ti a W b O x, Ti a Zn b O x, Ti a Zr b O x, V a Zn b O x, V a _{Zr b O x, W a Zn} b O x, W a Zr b O x, Y a Zr b O x, Zn a Zr b O x, frit added Monoiri _Al a _Ni b _{O x,} frit added Monoiri _Cr a Ti _b O _x, frit added Monoiri _Fe a _La b _{O x,} frit added Monoiri _Fe a _Ni b _{O x,} frit added Monoiri _Fe a _Ti b _{O x,} frit added Monoiri _Nb a _Ti b _{O x,} frit added Monoiri _Nb a _{W b} O _x , Ni _a Zn _b O _x with frit additive, Ni _a Zr _b O _x with frit additive, Sb _a Sn _b O _x with frit additive, Ta with frit additive _a Ti _b O _x , or Ti _a Zn _b O _x with frit additive, and / or M ¹ _a M ² _b M ³ _c O _x is Al _a Mg _b Zn _c O _x , Al _a Si _b V _c O _{x, Ba a Cu b Ti c} O x, Ca a Ce b Zr c O x, Co a Ni b Ti c O x, Co a Ni b Zr c O x, Co a Pb b Sn c O x, Co a Pb _{b Zn c O x, Cr a} Sr b Ti c O x, Cu a Fe b Mn c O x, Cu a La b Sr c O x, Fe a Nb b Ti c O x, Fe a Pb b Zn c O x _{, Fe a Sr b Ti c O} x, Fe a Ta b Ti c O x, Fe a W b Zr c O x, Ga a Ti b Zn c O x, La a Mn b Na c O x, La a Mn b Sr _c O _{x Mn a Sr b Ti c O x} , Mo a Pb b Zn c O x, Nb a Sr b Ti c O x, Nb a Sr b W c O x, Nb a Ti b Zn c O x, Ni a Sr b Ti _{c O x, Sn a W b} Zn c O x, Sr a Ti b V c O x, Sr a Ti b Zn c O x, or _Ti a _W b _Zr c may be included as an _{O x.}

In some other preferred embodiments, the metal oxide material is in an array of first and second chemical / electroactive materials, wherein the chemical / electroactive material is (i) the first material is M ¹ O _x and the second material is M ¹ _a M ² _b O _x .
(Ii) The first material is M ¹ O _x and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iii) The first material is M ¹ _a M ² _b O _x and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iv) the first material is first M ¹ O _x and the second material is second M ¹ O _x ;
(V) the first material is the first M ¹ _a M ² _b O _x , the second material is the second M ¹ _a M ² _b O _x , and (vi) the first material is the first M ¹ _a M ² _b M ³ _c O _x and the second material is the second M ¹ _a M ² _b M ³ _c O _x (where M ¹ is Ce, Co, Cu, Fe, Ga) , Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, Sc, Si, Sn, Sr, Selected from the group consisting of Ta, Ti, Tm, V, W, Y, Yb, Zn, and Zr, where M ² and M ³ are M ¹ _a M ² _b M ³ _c O _x are not the same, a, b and c are each independently about 0.0005 to about 1 and x is the charge of other elements in the compound Is enough to balance)
What is selected from the pairing in the group consisting of may be included.

  The semiconductor material may optionally contain one or more additives to promote adhesion to the substrate or to change the conductivity, resistance or selectivity of the sensor material. Examples of additives for promoting adhesion are frit that is crushed glass, or crushed inorganic material that changes to glass or enamel upon heating. Exemplary frits include those referred to as F2834, F3876, F2967, KH770, KH710 and KH375, available from DuPont iTechnologies. These may be used in amounts up to 30 volume percent of the composition from which the sensor material is made. Examples of additives for changing conductivity, resistance or selectivity include Ag, Au or Pt as well as frit.

  If necessary, the sensor material may also contain, for example, an additive that catalyzes the oxidation of the gas or enhances the selectivity for a particular analyte gas, or converts n-semiconductor to p-semiconductor or vice versa. One or more dopants may be included. These additives may be used in amounts up to 30 weight percent of the composition from which the sensor material is made. Any frit or other additive used does not need to be distributed uniformly or homogeneously throughout the sensor material as it is manufactured, but is localized on or near that particular surface as desired. May be. Each chemically / electroactive material may be covered with a porous dielectric overlayer, if desired. A preferred overlayer is QM44 from DuPont Eye Technologies.

  Any method of attaching the chemically / electroactive material to the substrate is suitable. One technique used for deposition is to apply a semiconductor material onto an alumina substrate on which electrodes are screen printed. The semiconductor material can be deposited on the top surface of the electrode by hand-coating the semiconductor material onto a substrate, nanopipeding the material into a well, thin film deposition, or thick film printing. Most techniques are followed by a final firing to sinter the semiconductor material.

Screen printing methods for electrodes and substrates with chemically / electroactive materials are illustrated in FIGS. FIG. 2 depicts a method of using a mating electrode overlaid with a dielectric to form a void hole into which a chemically / electroactive material can be deposited. FIG. 3 depicts an electrode screen pattern for an array of 6 materials printed on both sides of the substrate to provide a 12 material array chip. Two of the electrodes are in parallel, so that it only holds six unique materials. Counting down from the top surface of the array shown in FIG. 3, the top two materials can only be accessed simultaneously by the split electrodes they are in contact with. Below that for dielectrics that are screen-printed on top of the electrodes on both sides of the substrate to prevent contamination of the material by contact with the gas mixture, such as soot deposits that can cause shorts There is a screen pattern. Below that is a screen pattern for real semiconductor materials. This is printed in a hole in the dielectric on the top surface of the electrode. If more than one material is used in the array, each material is printed one by one.

  The electrical response is measured for each chemically / electroactive material upon exposure of the array to the gas mixture, and means for measuring the response include conductors interconnecting the sensor material. The conductors are in turn connected to electrical input and output circuit components, including data collection and manipulation devices as appropriate to measure and record the response exhibited by the sensor material in the form of an electrical signal. Response values, such as resistance related measurements, may be indicated by the size of the signal. Whether the analyte is one or more gases and / or one or more subgroups of gases, one or more signals are generated by the array of sensors for each analyte component in the mixture. It may be.

  The electrical response is measured separately for each individual chemical / electroactive material from that of each of the other chemical / electroactive materials. This can be done, for example, by having each chemically / electroactive material later access to current using a multiplexer to provide a differentiated signal between one material and another in the time domain or frequency domain. Can be achieved. Consequently, it is preferred that no chemically / electroactive material be connected in series circuit with any other such material. An electrode through which current is passed to the chemically / electroactive material can nevertheless be laid out to contact two or more materials. The electrode may be in contact with all, less than all, chemically / electroactive materials in the array. For example, if the array has twelve chemically / electroactive materials, the electrodes are each configured of 2, 3, 4, 5 or 6 (or more in each case more) groups of chemically / electroactive materials. May contact the element. The electrodes will preferably be laid out to allow current to be passed sequentially through each component of such group of chemically / electroactive materials.

  A conductor such as a printed circuit may be used to connect a power supply to the sensor material, and when a voltage is applied to the sensor material, a corresponding current is generated through the material. The voltage may be AC or DC, but the magnitude of the voltage will typically be kept constant. The resulting current is proportional to both the applied voltage and the resistance of the sensor material. The response of the material in either form of current, voltage or resistance is measured, and means for doing so include precision analog resistors, filter capacitors and commercial analog circuits such as operational amplifiers (such as OPA4340) Parts are included. Since voltage, current, and resistance are each a known function of the other two electrical characteristics, a known quantity for one characteristic may be easily converted to that of another characteristic.

Resistance may be measured, for example, in connection with digitization of the electrical response. Means for digitizing the electrical response include analog-to-digital (A / D) converters, such as those known in the art, including, for example, electrical and circuit components that involve the operation of a comparator. May be. The electrical response in the form of a voltage signal that occurs as described above as a result of applying a voltage to the sensor material is used as an input to a comparator portion (such as LM339). The other input to the comparator is driven by a linear ramp created by charging the capacitor with a constant current source consisting of an operational amplifier (such as LT1014) and an external transistor (such as PN2007A). The lamp is controlled and monitored by a microcomputer (such as T89C51CC01). The second comparator portion is also driven by the ramp voltage, but is compared to an accurate reference voltage. The microcomputer captures the length of time from the start of the ramp to the activation of the comparator and generates a signal based on the counted time.

  The resistance of the sensor material is then calculated as a value by the microcomputer from the ratio of the time signal resulting from the voltage output of the material to the known test voltage and ultimately the time signal corresponding to the resistance as a function of the test voltage. Or quantified. A microprocessor chip such as T89C51CC01 can be used for this function. The microprocessor chip also serves as a means for measuring the change in resistance of the sensor material by comparing the resistance measured as above with the value of the resistance previously measured.

  Electrical properties such as impedance or capacitance may be measured, for example, by the use of circuit components such as impedance meters, capacitance meters or inductance meters.

  Means for digitizing the temperature of an array of chemically / electroactive materials are described above, eg, converting a signal representative of a physical property, a temperature measuring device state or condition into a signal based on a count time Such parts can be included.

  In one embodiment, the analysis of the multi-component gas mixture is completed upon the occurrence of an electrical response, such as resistance, in the manner described above. Since the measurement of resistance exhibited by the sensor material upon exposure to the gas mixture is a function of the partial pressure in the mixture of one or more component gases, the measured resistance provides useful information regarding the composition of the gas mixture To do. The information may indicate, for example, the presence or absence in a mixture of a particular gas or subgroup of gases. However, in other embodiments, to obtain information regarding the relative concentration in the mixture of one or more specific component gases or subgroups, or in the mixture of one or more specific component gases or subgroups. It may be preferable to manipulate or further manipulate the electrical response in the manner necessary to calculate the concentration.

  Means for obtaining information on the relative concentration in the mixture of one or more individual component gases and / or one or more subgroups of gases, or one or more individual component gases and / or Means for detecting the presence in a mixture of subgroups or calculating the actual concentration include signal pre-processing and post-output processing as well as PLS (projection onto potential systems) models, back-propagation neural circuits Modeling algorithms that incorporate either a network model or a combination of the two may be included. Signal preprocessing includes operations such as principal component analysis, single linear transformation and scaling, log and natural log transformation, discrimination of raw signal values (eg, resistance), and discrimination of logarithmic values. It is not limited. The algorithms include models whose parameters have been previously determined and empirically model the relationship between the preprocessed input signal and information related to the gas concentration of the species. Post-output processing includes, but is not limited to, all of the operations listed above, and vice versa.

  The model is built using equations, where constants, coefficients or other factors are used to identify individual sensor materials to specific individual gases or subgroups that are expected to exist as components in the mixture to be analyzed. Derived from a predetermined value specific to an accurately measured electrical response. The equation may be constructed in any way that takes into account the temperature as a separate and separate value from the electrical response exhibited by the sensor material upon exposure to the gas mixture. Each individual sensor material of the array differs from each of the other sensors in its response to at least one of the constituent gases or subgroups in the mixture, and each of these different responses of the sensor is measured and used in the model Is used to construct the resulting equation.

The analyte gas contained in the mixture to which the chemical / electroactive material will be exposed is one or more mixed with an inert gas such as a single gas, a combined subgroup of gases, or nitrogen Gas or subgroup. Certain such gases are donor gas and acceptor gas. These donate electrons to semiconductor materials, such as carbon monoxide, H ₂ S and hydrocarbons, or semiconductors, such as O ₂ , nitrogen oxides (commonly expressed as NO _x ), and halogens. Either gas that accepts electrons from the material. When exposed to a donor gas, the n-type semiconductor material decreases in electrical resistance and increases current, and therefore it will show an increase in temperature due to I ² R heating. When exposed to an acceptor gas, an n-type semiconductor material will increase in electrical resistance and decrease current, and therefore will exhibit a decrease in temperature due to I ² R heating. The reverse occurs in each case for p-type semiconductor materials.

  The shape of the sensor material, such as its thickness, characteristics such as its thickness, the choice of compound or composition for use as a sensor, and the voltage applied to the array are required. It can vary depending on the sensitivity being used. The sensor material is preferably connected in parallel with a circuit in which a voltage of about 1 to about 20 volts, preferably about 1 to about 12 volts is applied to the sensor material. When analyzing a multi-component gas mixture, each chemical / electroactive sensor material in the array is in contact with each of the other chemical / electroactive materials in the array upon exposure to a mixture containing one or more analyte gases. Preferably exhibit different electrical response characteristics.

As stated, the types of electrical response characteristics that may be measured include AC impedance or resistance, capacitance, voltage, current or DC resistance. Resistance is preferably used as the electrical response characteristic of the sensor material, and the resistance is measured to perform an analysis of the gas mixture and / or components therein. For example, suitable sensor materials are at least about 1 ohm-cm, preferably at least about 10 ohm-cm, and still less than about 10 ⁶ ohm-cm, preferably at a temperature of about 400 ° C. or higher, preferably It may have a resistivity of about 10 ⁵ ohm-cm or less, more preferably about 10 ⁴ ohm-cm or less. Such a sensor material also preferably has a resistance of at least about 0.1 percent, preferably at least about 1 percent, when exposed to the gas mixture at a temperature of about 400 ° C. or higher, compared to the resistance without exposure. It may be characterized as an indication of change.

  Regardless of the type of response characteristic measured for the purpose of analyzing the mixture and / or the gas component therein, a sensor material is used in which the quantified value of the response characteristic is stable over time. It is desirable. When the sensor material is exposed to a mixture containing the analyte, the concentration of the analyte is a function of the composition of the specific gas mixture in which it is contained, and the value of the response of the sensor material is to the mixture over time at a constant temperature. Preferably remain constant or vary only slightly during the exposure. For example, the value of the response, even if it varies, is a period of at least about 1 minute, or preferably at least about 1 hour, preferably at least about 10 hours, more preferably at least about 100 hours, most preferably at least about 1000 hours. Will vary by no more than about 20 percent, preferably no more than about 10 percent, more preferably no more than about 5 percent, and most preferably no more than about 1 percent. One advantage of sensor materials of the type described above is that they are characterized by this kind of stability of response.

In applications where the gas mixture is at a temperature above about 400 ° C., the temperature of the sensor material and the array may be substantially measured only by the temperature of the gas mixture containing the gas analyte, and preferably is exclusively dependent on that temperature. Measured. This is typically a variable temperature. When higher temperature gases are being analyzed, it is desirable to equip the array with a heater to quickly bring the sensor material to the lowest temperature. However, once analysis has begun, the heater (if used) is typically switched off, providing no method for maintaining the sensor material at a preselected temperature. Thus, the temperature of the sensor material increases or decreases as much as the temperature of the surrounding environment increases or decreases. The ambient environment, and thus the temperature of the sensor and array, is typically measured (or derived from) only substantially the temperature of the gas mixture to which the array is exposed.

  In applications where the gas mixture is below about 400 ° C., it may be preferable to maintain the sensor material and array at a preselected temperature of about 400 ° C. or higher. This preselected temperature may be substantially constant or is preferably constant. The preselected temperature may be about 500 ° C. or higher, about 600 ° C. or higher, or about 700 ° C. or higher. This may conveniently be done with heaters built into the array in a manner known in the art. The temperature of the gas mixture may also be less than about 300 ° C, less than about 200 ° C, or less than about 100 ° C.

  Changes in the temperature of the array may be indicated by changes in the electrical response characteristics of the semiconductor material, such as a quantified value of resistance. At a constant partial pressure in the gas mixture, the value of the electrical response characteristic of the sensor material may change with changes in the temperature of the array and thus the material. This change in the value of the electrical response characteristic may be measured for the purpose of measuring or measuring the degree of change in temperature, and thus the value for temperature. It is preferred, but not required, that this measurement of temperature be made independently of information related to the composition content of the gas mixture. This is done by not using a sensor that provides compositional information for the additional purpose of measuring temperature, and possibly by connecting the temperature measuring device with the sensor material in a parallel circuit rather than in series. be able to. Means for measuring temperature include thermocouples or pyrometers built into the array of sensors. If the temperature measurement device is a thermistor that is typically a material that does not respond to the analyte gas, the thermistor is preferably manufactured from a material different from the material from which any of the gas sensors are manufactured. Regardless of the temperature or how the temperature change is measured, the temperature value or the quantified temperature change is preferably the desired input, in digitized form, from which the gas mixture and / or Analysis of the components therein may be performed.

  In the method and apparatus of the present invention, unlike the various prior art, it is not necessary to separate the constituent gases of the mixture for the purpose of performing the analysis, for example by means of a membrane or an electrolytic cell. When analyzing by means of the present invention, it is not necessary to use a reference gas, for example for the purpose of returning the response or analysis result to a baseline value. In the meantime, the sensor material is a mixture containing the analyte gas and / or subgroups, except for preliminary tests where a standardized response value is to be attributed to the exposure of each individual sensor material to each individual analyte gas. Only exposed to. The sensor material is not exposed to any other gas to obtain a response value for comparison with that obtained from exposure to the mixture containing the analyte. Therefore, analysis of the mixture is performed only from the electrical response obtained upon exposure of the chemically / electroactive material to the mixture containing the analyte. No information about the analyte gas and / or subgroup is inferred by exposure of the sensor material to any gas other than the analyte itself as contained within the mixture.

The present invention is therefore a method and apparatus for the direct detection of the presence and / or concentration of one or more gases in a multi-component gas system, selected for detecting gases in a multi-component gas stream Methods and apparatus are provided comprising at least two chemically / electroactive materials. The multi-component gas system can be essentially any temperature that is neither low nor high enough for the sensor material to decompose or otherwise malfunction the sensor device. In one embodiment, the gas system may be at a lower temperature, such as room temperature (about 25 ° C.) or otherwise in the range of about 0 ° C. to less than about 100 ° C., but in another embodiment the gas mixture is It may be at a higher temperature, such as in the range of about 400 ° C to about 1000 ° C.

  The present invention is applicable to gas mixtures that may be at higher temperatures, such as those found in combustion streams such as automobile, diesel engine or home heater exhaust or exhaust. However, the present invention is also at lower temperatures, such as in manufacturing processes, waste streams, and environmental monitoring, or in systems where odor detection is important and / or, for example, in the medical, agricultural or food and beverage industries It can also be applied to other source gas mixtures, such as in the system. An array of chemically / electroactive materials could be used, for example, to complement the gas chromatograph results or to calibrate the gas chromatograph. Thus, the gas mixture is about 100 ° C. or higher, about 200 ° C. or higher, about 300 ° C. or higher, about 400 ° C. or higher, about 500 ° C. or higher, about 600 ° C. or higher, about 700 At or above, or about 800 ° C. or above, but still below about 1000 ° C., below about 900 ° C., below about 800 ° C., below about 700 ° C., below about 600 ° C. Having a temperature that is less than about 500 ° C, less than about 400 ° C, less than about 300 ° C, less than about 200 ° C, or less than about 100 ° C.

  The present invention further provides a means for measuring, measuring and recording the response exhibited by each of the chemically / electroactive materials present in the array upon exposure to the gas mixture. For example, any means that will measure, measure and record changes in electrical properties can be used. This may be, for example, a device that can measure the change in AC impedance of the material as a function of the concentration of adsorbed gas molecules at their surface. Other means for measuring electrical properties may be suitable devices used for measuring capacitance, voltage, current or DC resistance, for example. Alternatively, the change in temperature of the sensing material may be measured and recorded. The chemical sensing method and apparatus may further provide a means for measuring or analyzing the mixture and / or the detection gas such that the presence of the gases is confirmed and their concentrations are measured. These means can include, for example, an instrument or device capable of performing chemometrics, neural networks or other pattern recognition methods. The chemical sensor device will further comprise a housing for the array of chemically / electroactive materials, detection means, and analysis means.

  The present invention is also a chemical sensor for directly detecting the presence and / or concentration of one or more gases in a multicomponent gas system comprising a substrate and one or more predetermined An array of at least two chemically / electroactive materials selected to detect gas and means for detecting changes in electrical properties in each of the chemically / electroactive materials present upon exposure to the gas system; A chemical sensor is also provided.

  The array of sensor materials should be able to detect the analyte in spite of the competitive reaction brought about by the presence of several other components of the multicomponent mixture. For this purpose, the present invention uses an array of multi-sensor materials, each of which has a different sensitivity to at least one of the gas components of the mixture to be detected, as described herein. . A sensor having the required sensitivity and capable of operating to produce analytical measurements and results of the type described above is then determined by selection of the appropriate composition of the material from which the sensor is manufactured. can get. Various compositions of materials suitable for this purpose are described above. The number of sensors in the array is typically greater than or equal to the number of individual gas components to be analyzed in the mixture.

The gas mixture to be analyzed may be exhausted by the process or may be the product of a chemical reaction that is sent to the device. In such cases, the apparatus of the present invention may further comprise means for utilizing the electrical response of the array, and optionally temperature measurements, for the purpose of controlling the process or device.

  Means for utilizing the electrical response of the sensor material, and optionally temperature measurement, to control the process or device include, for example, to control the chemical reaction of combustion that occurs in an internal combustion engine or to the engine itself Or a decision making routine for controlling the associated part or device.

  Combustion is a process in which the chemical reaction of the oxidation of hydrocarbon fuel occurs in the engine cylinder. An engine is a device to which the result of the chemical reaction is sent, which is the force produced by the combustion reaction for the work necessary to move the piston in the cylinder. Another example of a process that discharges a multicomponent mixture of gases is a chemical reaction that occurs in a fuel cell, and other examples of devices to which the product of the chemical reaction is sent are boilers such as those used in furnaces or for power generation Or a chimney scrubber to which waste gas is sent for pollution control treatment.

  In the case of an engine, a microcomputer (such as T89C51CC01) performs a number of decision-making routines with respect to various parameters of the combustion process or with respect to the operating characteristics of the engine in order to control the combustion process or the operation of the engine itself. . The microcomputer gathers information about the composition content of the engine exhaust and does so by obtaining the response of the array of chemically / electroactive materials exposed to the exhaust stream, and possibly temperature measurements. Information is temporarily stored in random access memory, and then the microcomputer adds one or more decision making routines to the information.

  The decision-making routine utilizes one or more algorithms and / or mathematical operations to manipulate the learned information and the desired state or situation to be handled by specific parameters of the process or by the operating characteristics of the device Brings decisions in the form of values that are equivalent. Based on the results of the decision-making routine, the instructions are provided or controlled by a microcomputer that provides adjustment of process parameters or device operating characteristics states or conditions. In the case of a process embodied by a chemical reaction of combustion, the process can be controlled by adjusting the parameters of the reaction, such as the relative amount of reactant supplied to it. The flow of fuel or air to the cylinder can be increased or decreased, for example. In the case of the engine itself, the device to which the result of the combustion reaction is sent, control can be achieved by adjusting the engine's operating characteristics such as torque or engine speed.

  The following non-limiting examples are intended to illustrate the invention but are in no way intended to limit it. In the examples provided below, the “chip” is used to describe an alumina substrate comprising an electrode, a sensing material, and a dielectric if a dielectric is used. The notation “X% A: MO” means that another inorganic compound (A) has been added to the metal oxide (MO) at the specified concentration (X% on an atomic basis). The term “frit” is used to describe a mixture of inorganic compounds that usually form glass at a certain temperature.

  Exemplary techniques that may be used to manufacture sensor materials and to measure signals using infrared (IR) thermographic and AC impedance methods are described below.

IR Thermographic Samples and Measurements The change in impedance of the sensor material when exposed to a gas or gas mixture may be measured by measuring the temperature change of the material sample by techniques such as infrared thermographic imaging. .

A. Array Chip Fabrication The interdigitated electrode pattern shown in FIG. 2 is screened onto an alumina substrate (obtained from Coors Tek, 96% alumina, 1 inch × 0.75 inch × 0.025 inch) Blank array chips were produced by printing. A semi-automatic screen printer (ETP electro-dial, series L-400) was used. Electrode paste is available from DuPont Eye Technologies, product # 5715. The electrode screen used (obtained from Microcircuit Engineering Corporation) had an emulsion thickness of 0.5 mil. After screen printing, the parts were dried in a convection oven at 120 ° C. for 10 minutes and then fired. Firing was performed in air using a 10 zone belt Lindberg furnace with a cycle time of 30 minutes and a peak temperature of 850 ° C. for 10 minutes. After firing the electrode onto the substrate, the dielectric (DuPont Eye Technologies, Product # 5704) pattern shown in FIG. 2 is applied to a screen (Microcircuit Engineering Corporation) having an emulsion thickness of 0.9 mil. Used to screen print on one side of the electrode. The parts were then dried at 120 ° C. for 10 minutes and fired using the same firing cycle as described above.

B. Semiconductor metal oxide production and application to array chips About 175 mg of semiconductor metal oxide powder or a mixture of semiconductor metal oxides with suitable glass frit (DuPont Eye Technologies products # F2889 or F3876) or other inorganic compounds Of a semiconducting metal oxide powder was weighed onto a glass slide with about 75 mg of a suitable medium (DuPont Eye Technologies product # M2619) and 1 mg of a suitable surfactant (DuPont Eye Technologies product # R0546). . The media and surfactant were mixed together and the metal oxide powder or mixture was gradually added to the media and surfactant to ensure wetting. If necessary, a suitable solvent (DuPont Eye Technologies product # R4553) was added at this time to reduce the viscosity. The paste was then transferred to an agate mortar and pestle for better mixing. Using a thin pointed wooden applicator, a very small amount of paste was then placed into one of the array chip wells. This procedure was repeated with each of the metal oxide powders or mixture until all of the wells on the array chip were filled. Once the wells on the array chip were filled with paste, the array chip was left in a closed chamber where a low flow of N ₂ gas passed over the chip. The array chip was then dried at 120 ° C. for 10 minutes. Firing was performed in air using a Fisher programmable box furnace at a rate of 1 ° C./min up to 650 ° C. and holding it at that temperature for 30 minutes. The cooling rate was 5 ° C./min to room temperature.

C. Array Chip Wiring Leads were manufactured using approximately 1.5 inches of 0.005 inch platinum wire. One end of the wire was bare and the other end was connected to a female RS232 connector. The bare end of the platinum lead was attached to one of the open conductor pads on the array chip using a conductive paste (Pelco product # 16023). The second lead was attached to the other open conductor pads on the array chip in the same manner. The chip was then dried at 120 ° C. for at least 4 hours.

D. IR Thermography Measurements The test chamber comprised a 2.75 inch cube containing gas flow inlet and outlet valves, a 1 inch MgF window, two thermocouple feedthroughs and two electrical feedthroughs. The electrical feedthrough consists of a sample heater (Advanced Ceramics, Volaelectric heater # HT-42) and a voltage / current measuring device (Keithley Instruments).
Instruments) model # 236) was provided. The gas flow was adjusted using a multi-gas controller (MKS model # 647B). The sample heater was controlled using an apparatus (70 VAC / 700 W phase angle) manufactured by Hampton Controls. The infrared camera (Inframetrics PM390) was focused on the front of the array chip using a 100 μm close-up lens throughout the measurement.

Prior to taking measurements, the samples were placed on the top surface of the sample heater in the test room. The mespin on the lead wire connected to the array chip was then connected to an electrical feedthrough connected to a voltage / current measuring device. The chamber was closed and placed in the IR camera viewing path. Gas (100 sccm N ₂ , 25 sccm O ₂ ) was then allowed to flow into the chamber during sample heating. The sample was then heated to the desired temperature (about 10 ° C./min) and allowed to equilibrate before the voltage / current measurement device was turned on and the voltage applied. The voltage was typically adjusted to pass 10-20 mA of current through the array.

IR thermographic images of the array of materials were taken from the following gases (N ₂ , O ₂ , and 1% CO / 99% N ₂ , 1% NO ₂ /99% N ₂ and 1% C ₄ H ₁₀ /99% N ₂ ) Photographed 20 minutes after each change in the flow. Unless stated otherwise, the contents of all gas mixtures described below are given in volume percent. In order to determine the temperature signal in the examples, the temperature of the materials in 2% O ₂ /98% N ₂ was subtracted from their temperature in the other gas mixtures. A Thermmonitor 95 Pro (Pro), version 1.61 (Thermotechnix Systems, Ltd.) was used to perform the temperature subtraction. When exposed to donor gas, the n-type semiconductor material will show an increase in temperature due to I ² R heating, as the resistivity decreases and the current increases. When exposed to an acceptor gas, the n-type semiconductor material will exhibit a decrease in temperature due to I ² R heating, as the resistivity increases and the current decreases. The reverse occurs for p-type semiconductor materials.

AC impedance sample and measurement Semiconductor Metal Oxide Paste Preparation Semiconductor Metal Oxide Mixtures with about 2-3 grams of semiconductor metal oxide powder or suitable glass frit (DuPont Eye Technologies products # F2889 or F3876) or other inorganic compounds The oxide mixture was weighed with a sufficient amount of a suitable medium (DuPont Eye Technologies product # M2619) to give about 40-70 wt% solids. The materials were then transferred to a blender (Hoover automatic blender, model # M5) where they were mixed together using a spatula until no dry powder remained. If necessary, a suitable surfactant, such as DuPont Eye Technologies product # R0546, was added to reduce the viscosity. Further mixing was done using a 500 gram weight grinder for about 6 passes at 25 revolutions per pass. The finished paste was then transferred to a container until needed.

B. Single Sensor Fabrication Several of the sensing chips were fabricated using a single material rather than an array of sensing materials. Screen an electrode pattern 0.4 inches long and interdigitated with electrodes spaced 0.008 inches onto an alumina substrate (Coors Tech, 96% alumina, 1 inch x 1 inch x 0.025 inch) A single sensing sample chip was manufactured by printing. A semi-automatic screen printer (ETP electro-dial, series L-400) was used. Electrode paste (Product # 5715) is available from DuPont Eye Technologies. The electrode screen (Microcircuit Engineering Corporation) had an emulsion thickness of 0.5 mil. After printing, the paste was dried in a convection oven at 120 ° C. for 10 minutes and then fired. Firing was performed using a 10 zone belt furnace (Lindberg) for a cycle time of 30 minutes and a peak temperature of 850 ° C. for 10 minutes. The sensor material was then screen printed onto the substrate using a 0.5 inch by 0.5 inch aperture screen (Microcircuit Engineering Corporation). This screen had an emulsion thickness of 1.0 mil. After printing the sensor material, the part was dried in a convection oven at 120 ° C. for 10 minutes. At this point, the parts were fired in air at 850 ° C. for 10-45 minutes using a Lindberg tube furnace.

C. Sensor Array Manufacturing A variety of electrodes and sensor arrangements can be used to acquire sensor array AC impedance data. The production of the 12 material array is described immediately below.

  A sensor array chip was fabricated by screen printing an electrode pattern (FIG. 3) onto an alumina substrate (Coors Tech, 96% alumina, 2.5 inch × 0.75 inch × 0.040 inch). A semi-automatic screen printer (ETP electro-dial, series L-400) was used. Electrode paste (Product # 4597) is available from DuPont Eye Technologies. The electrode screen (Microcircuit Engineering Corporation) had an emulsion thickness of 0.4 mil. Note that in FIG. 3, two of the sensor pads are in parallel, so that only six unique sensor material measurements can be made from this electrode arrangement. After printing, the paste was dried in a convection oven at 130 ° C. for 10 minutes and then fired. Firing was performed in air using a 10 zone belt furnace (Lindberg) with a cycle time of 30 minutes and a peak temperature of 850 ° C. for 10 minutes. After firing the electrode onto the substrate, the dielectric (DuPont Eye Technologies, product # QM44) pattern shown in FIG. 3 is used on a screen (Microcircuit Engineering Corporation) having an emulsion thickness of 1.0 mil. Screen printed on one side of the electrode. The parts were then dried at 130 ° C. for 10 minutes and fired using the same firing cycle as described above. At this point, each sensor material was screen printed into a dielectric well on the substrate using the screen (Microcircuit Engineering Corporation) shown in FIG. This screen had an emulsion thickness of 1.0 mil. After printing each sensor material, the parts were dried in a convection oven at 130 ° C. for 10 minutes. After all of the sensor material (6) was deposited on this side of the sensor, the part was fired using the same firing cycle described above. After this firing step, the above printing, drying and firing steps were repeated on the backside of the substrate to add another 6 sensor materials to the array chip.

D. AC Impedance Measurement For a single sensor material sample, a 1.2 inch platinum wire was connected to each of the electrodes on the sample with a stainless steel screw. The end of the platinum wire was then connected to a 0.127 inch diameter Inconel wire that reached the outside of the test chamber. The entire length of the Inconel wire was completely wrapped with aluminum oxide, and the Inconel tube was grounded to eliminate interference from the electromagnetic field present in the furnace. The Inconel tube was welded into a stainless steel flange mounted on the end of a closed-one-end fused quartz reactor that was 4 inches in diameter and 24 inches long. A grounded stainless steel screen was wrapped around the quartz reactor to similarly eliminate electromagnetic interference from the furnace. The whole chamber assembly was placed in the cavity of a hinged Lindberg tube furnace and the furnace was closed.

  10 pairs of coaxial cables (one pair per sample) and a pair of switches to the interface and analyzer exit the sample from the Inconel wire on the outside of the furnace and reach the switch (Caysley 7001 containing two Kaysley 7062 high frequency cards). To a dielectric interface (Solartron 1296) and a frequency response analyzer (Solartron 1260). The switch, dielectric interface and frequency analyzer were all computer controlled.

  The gas flow into the quartz chamber was regulated using a computer control system consisting of four independent flow meters (MKS product # 1179) and a multi-gas controller (MKS product # 647B). The furnace temperature was measured using a computer controlled fuzzy logic controller (Fuji PYX).

After placing the sample into the furnace, the quartz reactor was purged with a synthetic air mixture throughout the furnace heating. After the furnace is equilibrated at the measured temperature, the gas concentrations (N ₂ , O ₂ , 1% CO / 99% N ₂ , and 1% NO ₂ /99% N ₂ ) are set to the desired values in the reactor Sufficient time was allowed for atmospheric equilibrium. At this time, AC impedance measurement values (1 Hz to 1 MHz) were sequentially measured from each sample. The gas concentration was then typically set to a new value, the atmosphere was equilibrated, and another round of measurements was taken. The procedure was repeated until the sample was measured in all of the desired atmosphere at the specified temperature. At this point the temperature was changed and the process was repeated. After all measurements were taken, the furnace was cooled to room temperature and a sample was removed.

  For the sensor array chip, a measurement system similar to that described above can be used. The only difference is that the platinum wire connected to the Inconel wire in the furnace must be connected to the electrode pads on the array chip using a conductive paste (Pelco product # 16023). The number of connections from the sample to the switch depends on the number of sensors on the array.

Example 1
This example shows the change in electrical properties of 20 metal oxide semiconductor materials in the presence of 4 combustion gas compositions at 450 ° C. The signals listed in Table 1 below are from the infrared thermography method described above. The signal represents the difference in temperature (° C.) of the material when exposed to one of the four gas compositions shown compared to that with a reference gas that is 2% O ₂ /98% N ₂ , Reflects changes in electrical resistance of semiconductor materials. All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

The next measurement was performed at a voltage other than 10V. Pr ₆ O ₁₁ is measured using 1V, BaCuO _2.5 , CuMnFeO ₄ , CuGaO ₂ and CuFe ₂ O4 are measured using 16V, Zn ₄ TiO ₆ is measured using 20V, LaCuO ₄ and SrCu ₂ O ₂ was measured using 12V.

Example 2
This example shows the change in electrical properties of eight metal oxide semiconductor materials in the presence of five combustion gas compositions at 450 ° C. The signals listed in Table 2 below are from the infrared thermography method. The signal is the difference in temperature (° C.) of the semiconductor material when exposed to the indicated gas composition compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All of the signals were generated at 10V across the semiconductor material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

Example 3
This example shows the change in electrical properties of 26 metal oxide semiconductor materials in the presence of 4 combustion gas compositions at 600 ° C. The signals listed immediately below in Table 3 were obtained using the infrared thermography method. The signal is a measure of the difference in temperature (° C.) of the material when exposed to the indicated gas composition compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

All of the measured values are BaCuO _2.5 measured at 4 V, Fe ₂ O ₃ measured at 1 V, ZnO + 2.5% F2889, ZnO + 10% F3876, SnO ₂ + 5% F2889, Tm ₂ O ₃ , Yb ₂ O ₃ , Fe: ZrO ₂ and MnCrO ₃ were measured at 5V, WO ₃ + 10% F3876 was measured at 2V, CuFe ₂ O ₄ was measured at 6V, and Zn ₄ TiO ₆ and ZnTiO ₃ were measured using 20V. Except that, it was obtained using 10V.

Example 4
This example shows that a set of four metal oxide materials of Example 3 could be used to distinguish the four gas compositions shown at 600 ° C. using IR thermography signals. The results are shown in Table 4 below. The signal is a measure of the difference in temperature (° C.) of the material when exposed to the indicated gas compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

Example 5
This example demonstrates that this second set of four metal oxide materials of Example 3 could be used to distinguish the four gas compositions shown at 600 ° C. using IR thermography signals. To do. The results are shown in Table 5 below. The signal is a measure of the difference in temperature (° C.) of the material when exposed to the indicated gas compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

Comparative Example A
This comparative example demonstrates that this set of six metal oxide materials of Example 3 could not be used to distinguish two gas compositions at 600 ° C. using IR thermography signals. Illustrate the importance of proper selection of. The results are shown in Table 5A below. The signal is a measure of the difference in temperature (° C.) of the material when exposed to the indicated gas composition compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

Comparative Example B
This comparative example demonstrates that this set of three materials could not be used to distinguish between the two gas compositions at 600 ° C. using IR thermographic signals, highlighting the importance of proper selection of materials. Illustrate. The results are shown in Table 5B below. The signal is a measure of the difference in temperature (° C.) of the material when exposed to the indicated gas composition compared to that with a reference gas that is 2% O ₂ /98% N ₂ . All signals were generated at 10V across the material unless otherwise stated. The blank indicates that there was no detectable signal when the gas composition was contacted with the material. Gas was measured at 2000 ppm in N ₂ unless otherwise stated.

Example 6
This example illustrates the use of the AC impedance method to measure the response of 19 metal oxide semiconductor materials in the presence of 4 gas compositions at 400 ° C. The signal listed in Table 6 below is the ratio of the magnitude of impedance at 10,000 ppm O ₂ in N _{2 to} the magnitude of the impedance of the material when exposed to the indicated gas composition. Gas used was 1000ppmCO and _{N 2} of 200PpmNO ₂ and 10,000PpmO _{2, N 2} in 200PpmNO _{2, N 2} in _{N 2.}

Example 7
This example illustrates the use of the AC impedance method to measure the response of 19 metal oxide semiconductor materials in the presence of 4 gas compositions at 550 ° C. The signals listed in the table are from the AC impedance method. The signal is the ratio of the magnitude of the impedance at 10,000 ppm O ₂ in N _{2 to} the magnitude of the impedance of the material when exposed to the indicated gas composition. Gas used was 1000ppmCO and _{N 2} of 200PpmNO ₂ and 10,000PpmO _{2, N 2} in 200PpmNO _{2, N 2} in _{N 2.}

Example 8
This example illustrates the use of the AC impedance method to measure the response of 23 semiconductor materials in the presence of 4 gas compositions at 650-700 ° C. The signals listed in the table are from the AC impedance method. The signal is the ratio of the magnitude of the impedance at 10,000 ppm O ₂ in N _{2 to} the magnitude of the impedance of the material when exposed to the indicated gas composition. Gas used was 1000ppmCO and _{N 2} of 200PpmNO ₂ and 10,000PpmO _{2, N 2} in 200PpmNO _{2, N 2} in _{N 2.}

Example 9
This example illustrates the use of the AC impedance method to measure the response of 16 semiconductor materials in the presence of 4 gas compositions at 800 ° C. The signals listed in the table are from the AC impedance method. The signal is the ratio of the magnitude of the impedance at 10,000 ppm O ₂ in N _{2 to} the magnitude of the impedance of the material when exposed to the indicated gas composition. Gas used was 1000ppmCO and _{N 2} of 200PpmNO ₂ and 10,000PpmO _{2, N 2} in 200PpmNO _{2, N 2} in _{N 2.}

Claims (114)

A multi-component gas mixture analyzer comprising:
(A) an array of at least two chemically / electroactive materials, wherein each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture;
(B) means for individually measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture;
(C) means for measuring the temperature of the array;
(D) an apparatus comprising: means for digitizing the electrical response and temperature measurement.   The apparatus of claim 1, wherein the array is placed in a gas mixture and the gas mixture has a temperature of about 400 ° C. or higher.   The apparatus of claim 1 wherein the gas mixture is exhaust gas from a combustion process.   The apparatus according to claim 1, wherein the component gases in the gas mixture are not separated.   The apparatus of claim 1 wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable.   The apparatus of claim 1, wherein the electrical response of the chemically / electroactive material is measured upon exposure to the multi-component gas mixture only.   The apparatus of claim 1, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 2. The apparatus of claim 1, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to b) the resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. The apparatus of claim 1, wherein the apparatus is constant during the exposure of the material to the gas mixture of or changes by no more than about 20 percent.   The apparatus of claim 1, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   The apparatus of claim 1, wherein the at least one chemically / electroactive material is a metal oxide.   Means for the multi-component gas mixture to be exhausted by the process or the product of a chemical reaction that is sent to the device, and for the apparatus to use electrical response and temperature measurements to control the process or device The apparatus of claim 1 further comprising: An apparatus for calculating the concentration of at least two individual analyte gas components in a multi-component gas mixture having a temperature of about 400 ° C. or higher comprising:
(A) an array is placed in the gas mixture and each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the gas mixture; An array of at least three chemically / electroactive materials;
(B) means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to only unseparated components of the gas mixture;
(C) means for calculating the concentration of individual analyte gas components from the electrical response of the chemically / electroactive material.   14. The apparatus of claim 13, wherein the gas mixture is exhaust gas from a combustion process.   The apparatus of claim 13, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable. (I) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 14. The apparatus of claim 13, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to ii) resistance prior to exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 14. The apparatus of claim 13, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   14. The device of claim 13, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   The apparatus of claim 13, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device The apparatus of claim 13 comprising: An apparatus for calculating the concentration of at least two individual analyte gas components in a multi-component gas mixture having a temperature of about 400 ° C. or higher comprising:
(A) an array of at least three chemically / electroactive materials, wherein an array is placed in the gas mixture and each chemically / electroactive material exhibits a change in electrical resistance upon exposure to the gas mixture, wherein at least one chemo / electro-active material, when in about 400 ° C. or higher temperature has an electrical resistivity of (i) about 1 ohm -cm~ about 10 ⁵ ohm -cm range and, (ii ) An array that exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to the gas mixture as compared to resistance before exposure;
(B) means for measuring the change in resistance of each chemically / electroactive material individually upon exposure of the array to the gas mixture;
(C) means for calculating the concentration of individual analyte gas components from the change in resistance of the chemically / electroactive material.   The apparatus of claim 21, wherein the gas mixture is an exhaust gas from a combustion process.   The apparatus of claim 21, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable.   The change in resistance of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the resistance value of the material is at a selected temperature for a period of at least about 1 minute. 24. The apparatus of claim 21, wherein the apparatus is constant during exposure of the material to the gas mixture or varies by no more than about 20 percent.   The apparatus of claim 21, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the change in resistance to control the process or device The apparatus of claim 21 comprising: A multi-component gas mixture analyzer comprising:
(A) each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture at a selected temperature; An array of at least two chemically / electroactive materials, the electrical response characteristic of which can be quantified as a value, wherein the value of the response of the material to the gas mixture for a period of at least about 1 minute at the selected temperature An array that is constant during exposure of the material or changes by no more than about 20 percent;
(B) a device comprising: means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture.   28. The apparatus of claim 27, wherein the array is placed in a gas mixture and the gas mixture has a temperature of about 400 degrees Celsius or higher.   28. The apparatus of claim 27, wherein the gas mixture is exhaust gas from a combustion process.   28. The apparatus of claim 27, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component.   28. The apparatus of claim 27, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable.   28. The apparatus of claim 27, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   28. The apparatus of claim 27, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device 28. The apparatus of claim 27, comprising: An apparatus for analyzing a gas mixture in a multi-component gas mixture having a temperature of less than about 400 ° C., comprising:
(A) at least two chemical / electroactive materials, each chemical / electroactive material exhibiting different electrical response characteristics than each of the other chemical / electroactive materials upon exposure to the gas mixture at a selected temperature; An array of active materials disposed within the gas mixture and having a substantially constant temperature of about 400 ° C. or higher;
(B) a device comprising: means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture.   36. The apparatus of claim 35, wherein the component gases in the gas mixture are not separated.   36. The apparatus of claim 35, wherein the electrical response of the chemically / electroactive material is measured upon exposure to the multi-component gas mixture only.   36. The apparatus of claim 35, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component.   36. The apparatus of claim 35, further comprising means for measuring the temperature of the gas mixture and means for digitizing the electrical response and temperature measurement. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 36. The device of claim 35, wherein the device exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to the resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 36. The apparatus of claim 35, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   36. The apparatus of claim 35, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   36. The apparatus of claim 35, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device 36. The apparatus of claim 35, comprising: A multi-component gas mixture analyzer comprising:
(A) first and second chemistries wherein each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the gas mixture at a selected temperature; An array of electroactive materials, wherein the chemically / electroactive materials are
(I) the first material is M ¹ O _x and the second material is M ¹ _a M ² _b O _x ;
(Ii) a first material is ^M 1 _{O x,} and the second material is _{^{M 1 a M 2 b M 3}} c O x,
(Iii) The first material is M ¹ _a M ² _b O _x , and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iv) the first material is first M ¹ O _x and the second material is second M ¹ O _x ;
(V) the first material is a first M ¹ _a M ² _b O _x and the second material is a second M ¹ _a M ² _b O _x ; and (vi) the first The material is a first M ¹ _a M ² _b M ³ _c O _x and the second material is a second M ¹ _a M ² _b M ³ _c O _x where M ¹ is Ce , Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, sc, Si, Sn, Sr, Ta, Ti, Tm, V, W, Y, Yb, Zn, and is selected from the group consisting of Zr, ^{M 2} Contact Fine ^{M 3} are not the same as in _{^{M 1 a M 2 b M 3}} c O x, a, b and c are from about 0.0005 to about 1 independently, and oxygen is the x is present Sufficient to balance the charge of other elements in the compound)
An array selected from pairing in the group consisting of:
(B) a device comprising: means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture. (A) M ¹ O _x is Ce _a O _x , CoO _x , CuO _x , FeO _x , GaO _x , NbO _x , NiO _x , PrO _x , RuO _x , SnO _x , Ta _a O _x , TiO _x , TmO _x WO _x , YbO _x , ZnO _x , ZrO _x , SnO _x with Ag additive, ZnO _{x with} Ag additive, TiO _{x with} Pt additive, ZnO _x with frit additive, NiO _x with frit additive, SnO _{x with} frit additive, or Selected from the group consisting of WO _{x with} frit additive,
_{^{(B) M 1 a M 2}} b O x is _{Al a Cr b O x, Al} a Fe b O x, Al a Mg b O x, Al a Ni b O x, Al a Ti b O x, Al a V _{b O x, Ba a Cu b} O x, Ba a Sn b O x, Ba a Zn b O x, Bi a Ru b O x, Bi a Sn b O x, Bi a Zn b O x, Ca a Sn b O _x , Ca _a Zn _b O _x , Cd _a Sn _b O _x , Cd _a Zn _b O _x , Ce _a Fe _b O _x , Ce _a Nb _b O _x , Ce _a Ti _b O _x , Ce _a V _b O _{x, Co a Cu b O x} , Co a Ge b O x, Co a La b O x, Co a Mg b O x, Co a Nb b O x, Co a Pb b O x, Co a Sn b O x _{, Co a V b O x,} Co a W b O x, Co a _{n b O x, Cr a Cu} b O x, Cr a La b O x, Cr a Mn b O x, Cr a Ni b O x, Cr a Si b O x, Cr a Ti b O x, Cr a Y _{b O x, Cr a Zn b} O x, Cu a Fe b O x, Cu a Ga b O x, Cu a La b O x, Cu a Na b O x, Cu a Ni b O x, Cu a Pb b _{O x, Cu a Sn b O} x, Cu a Sr b O x, Cu a Ti b O x, Cu a Zn b O x, Cu a Zr b O x, Fe a Ga b O x, Fe a La b O _{x, Fe a Mo b O x} , Fe a Nb b O x, Fe a Ni b O x, Fe a Sn b O x, Fe a Ti b O x, Fe a W b O x, Fe a Zn b O x _{, Fe a Zr b O x,} Ga a La b O _{, Ga a Sn b O x,} Ge a Nb b O x, Ge a Ti b O x, In a Sn b O x, K a Nb b O x, Mn a Nb b O x, Mn a Sn b O x, Mna _a Ti _b O _x , Mna _a Y _b O _x , Mna _a Zn _b O _x , Mo _a Pb _b O _x , Mo _a Rb _b O _x , Mo _a Sn _b O _x , Mo _a Ti _b O _x , Mo _a Zn _b O _x , Nb _a Ni _b O _x , Nb _a Ni _b O _x , Nb _a Sr _b O _x , Nb _a Ti _b O _x , Nb _a W _b O _x , Nb _a Zr _b O _x , Ni _{a Si b O x, Ni a Sn} b O x, Ni a Y b O x, Ni a Zn b O x, Ni a Zr b O x, Pb a Sn b O x, Pb a Zn b O x, Rb a W _{b O x, Ru a Sn b} O x, Ru a W b _{x, Ru a Zn b O x} , Sb a Sn b O x, Sb a Zn b O x, Sc a Zr b O x, Si a Sn b O x, Si a Ti b O x, Si a W b O x _{, Si a Zn b O x,} Sn a Ta b O x, Sn a Ti b O x, Sn a W b O x, Sn a Zn b O x, Sn a Zr b O x, Sr a Ti b O x, _{Ta a Ti b O x, Ta} a Zn b O x, Ta a Zr b O x, Ti a V b O x, Ti a W b O x, Ti a Zn b O x, Ti a Zr b O x, V _{a Zn b O x, V a} Zr b O x, W a Zn b O x, W a Zr b O x, Y a Zr b O x, Zn a Zr b O x, frit added Monoiri _Al a _Ni b _{O x} , Cr _a Ti _b O _{x with} frit additive, Tsu DOO added Monoiri _Fe a _La b _{O x,} frit added Monoiri _Fe a _Ni b _{O x,} frit added Monoiri _Fe a _Ti b _{O x,} frit added Monoiri _Nb a _Ti b _{O x,} frit added Monoiri _Nb a _W b _{O x} , Ni _a Zn _b O _x with frit additive, Ni _a Zr _b O _x with frit additive, Sb _a Sn _b O _x with frit additive, Ta _a Ti _b O _x with frit additive, or Ti _a Zn _b O _x with frit additive It is selected from the group consisting of _x, and / or _{^{(c) M 1 a M 2}} b M 3 c O x is _{Al a Mg b Zn c O x} , Al a Si b V c O x, Ba a Cu b Ti c _{O x, Ca a Ce b Zr} c O x, Co a Ni b Ti c O x, Co a Ni b Zr c O x, Co a Pb b S _{c O x, Co a Pb b} Zn c O x, Cr a Sr b Ti c O x, Cu a Fe b Mn c O x, Cu a La b Sr c O x, Fe a Nb b Ti c O x, Fe _{a Pb b Zn c O x,} Fe a Sr b Ti c O x, Fe a Ta b Ti c O x, Fe a W b Zr c O x, Ga a Ti b Zn c O x, La a Mn b Na c _{O x, La a Mn b Sr} c O x, Mn a Sr b Ti c O x, Mo a Pb b Zn c O x, Nb a Sr b Ti c O x, Nb a Sr b W c O x, Nb a _{Ti b Zn c O x, Ni} a Sr b Ti c O x, Sn a W b Zn c O x, Sr a Ti b V c O x, Sr a Ti b Zn c O x or _Ti a _W b Zr _c, from the group consisting of O _x The apparatus of claim 45 which is-option.   46. The apparatus of claim 45, wherein the array is placed in a gas mixture and the gas mixture has a temperature of about 400 ° C. or higher.   46. The apparatus of claim 45, wherein the gas mixture is exhaust gas from a combustion process.   46. The apparatus of claim 45, wherein the component gases in the gas mixture are not separated.   46. The apparatus of claim 45, wherein the electrical response of the chemically / electroactive material is measured upon exposure to the multi-component gas mixture only.   46. The apparatus of claim 45, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component.   46. The apparatus of claim 45, further comprising means for measuring the temperature of the gas mixture and means for digitizing the electrical response and temperature measurement.   46. The apparatus of claim 45, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 46. The apparatus of claim 45, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to the resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 46. The apparatus of claim 45, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   46. The apparatus of claim 45, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device 46. The apparatus of claim 45, comprising: A multi-component gas mixture analyzer comprising:
(A) a chemically / electroactive material, wherein each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the gas mixture at a selected temperature; An array, wherein at least one chemically / electroactive material is M ¹ O _x , M ¹ _a M ² _b O _x and M ¹ _a M ² _b M ³ _c O _x
Wherein M ¹ is selected from the group consisting of Ce, Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, Sc, Si, Sn, Sr, Ta, Ti, Tm, V, W, Y, Yb, Zn, and Zr are selected, but M ² and M ³ are M ¹ _a M ² _b M ³ _c O _x are not the same, a, b and c are each independently about 0.0005 to about 1, and x is the other oxygen in the compound Selected from the group consisting of a sufficient number to balance the charge of the element) And the array,
(B) a device comprising: means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture. (A) M ¹ O _x is Ce _a O _x , CoO _x , CuO _x , FeO _x , GaO _x , NbO _x , NiO _x , PrO _x , RuO _x , SnO _x , Ta _a O _x , TiO _x , TmO _x WO _x , YbO _x , ZnO _x , ZrO _x , SnO _x with Ag additive, ZnO _{x with} Ag additive, TiO _{x with} Pt additive, ZnO _x with frit additive, NiO _x with frit additive, SnO _{x with} frit additive, or Selected from the group consisting of WO _{x with} frit additive,
_{^{(B) M 1 a M 2}} b O x is _{Al a Cr b O x, Al} a Fe b O x, Al a Mg b O x, Al a Ni b O x, Al a Ti b O x, Al a V _{b O x, Ba a Cu b} O x, Ba a Sn b O x, Ba a Zn b O x, Bi a Ru b O x, Bi a Sn b O x, Bi a Zn b O x, Ca a Sn b O _x , Ca _a Zn _b O _x , Cd _a Sn _b O _x , Cd _a Zn _b O _x , Ce _a Fe _b O _x , Ce _a Nb _b O _x , Ce _a Ti _b O _x , Ce _a V _b O _{x, Co a Cu b O x} , Co a Ge b O x, Co a La b O x, Co a Mg b O x, Co a Nb b O x, Co a Pb b O x, Co a Sn b O x _{, Co a V b O x,} Co a W b O x, Co a _{n b O x, Cr a Cu} b O x, Cr a La b O x, Cr a Mn b O x, Cr a Ni b O x, Cr a Si b O x, Cr a Ti b O x, Cr a Y _{b O x, Cr a Zn b} O x, Cu a Fe b O x, Cu a Ga b O x, Cu a La b O x, Cu a Na b O x, Cu a Ni b O x, Cu a Pb b _{O x, Cu a Sn b O} x, Cu a Sr b O x, Cu a Ti b O x, Cu a Zn b O x, Cu a Zr b O x, Fe a Ga b O x, Fe a La b O _{x, Fe a Mo b O x} , Fe a Nb b O x, Fe a Ni b O x, Fe a Sn b O x, Fe a Ti b O x, Fe a W b O x, Fe a Zn b O x _{, Fe a Zr b O x,} Ga a La b O _{, Ga a Sn b O x,} Ge a Nb b O x, Ge a Ti b O x, In a Sn b O x, K a Nb b O x, Mn a Nb b O x, Mn a Sn b O x, Mna _a Ti _b O _x , Mna _a Y _b O _x , Mna _a Zn _b O _x , Mo _a Pb _b O _x , Mo _a Rb _b O _x , Mo _a Sn _b O _x , Mo _a Ti _b O _x , Mo _a Zn _b O _x , Nb _a Ni _b O _x , Nb _a Ni _b O _x , Nb _a Sr _b O _x , Nb _a Ti _b O _x , Nb _a W _b O _x , Nb _a Zr _b O _x , Ni _{a Si b O x, Ni a Sn} b O x, Ni a Y b O x, Ni a Zn b O x, Ni a Zr b O x, Pb a Sn b O x, Pb a Zn b O x, Rb a W _{b O x, Ru a Sn b} O x, Ru a W b _{x, Ru a Zn b O x} , Sb a Sn b O x, Sb a Zn b O x, Sc a Zr b O x, Si a Sn b O x, Si a Ti b O x, Si a W b O x _{, Si a Zn b O x,} Sn a Ta b O x, Sn a Ti b O x, Sn a W b O x, Sn a Zn b O x, Sn a Zr b O x, Sr a Ti b O x, _{Ta a Ti b O x, Ta} a Zn b O x, Ta a Zr b O x, Ti a V b O x, Ti a W b O x, Ti a Zn b O x, Ti a Zr b O x, V _{a Zn b O x, V a} Zr b O x, W a Zn b O x, W a Zr b O x, Y a Zr b O x, Zn a Zr b O x, frit added Monoiri _Al a _Ni b _{O x} , Cr _a Ti _b O _{x with} frit additive, Tsu DOO added Monoiri _Fe a _La b _{O x,} frit added Monoiri Fe _a
Ni _b O _x , Fe _a Ti _b O _x with frit additive, Nb _a Ti _b O _x with frit additive, Nb _a W _b O _x with frit additive, Ni _a Zn _b O _x with frit additive, Ni _{a with} frit additive Selected from the group consisting of Zr _b O _x , Sb _a Sn _b O _x with frit additive, Ta _a Ti _b O _x with frit additive, or Ti _a Zn _b O _{x with} frit additive, and / or (c) M ^{1 _{a M 2 b M 3 c O}} x is _{Al a Mg b Zn c O x} , Al a Si b V c O x, Ba a Cu b Ti c O x, Ca a Ce b Zr c O x, Co a Ni b _{Ti c O x, Co a Ni} b Zr c O x, Co a Pb b Sn c O x, Co a Pb b Zn c O x, Cr a Sr b Ti _{O x, Cu a Fe b Mn} c O x, Cu a La b Sr c O x, Fe a Nb b Ti c O x, Fe a Pb b Zn c O x, Fe a Sr b Ti c O x, Fe a _{ta b Ti c O x, Fe} a W b Zr c O x, Ga a Ti b Zn c O x, La a Mn b Na c O x, La a Mn b Sr c O x, Mn a Sr b Ti c O _{x, Mo a Pb b Zn c} O x, Nb a Sr b Ti c O x, Nb a Sr b W c O x, Nb a Ti b Zn c O x, Ni a Sr b Ti c O x, Sn a W _b Zn _c O _x, according to _{Sr a Ti b V c O x} , Sr a Ti b Zn c O x or _Ti a _W b _Zr c _{O x} claim 58 which is selected from the group consisting of.   59. The apparatus of claim 58, wherein the array is placed in a gas mixture, and the gas mixture has a temperature of about 400 degrees Celsius or higher.   59. The apparatus of claim 58, wherein the gas mixture is exhaust gas from a combustion process.   59. The apparatus of claim 58, wherein the component gases in the gas mixture are not separated.   59. The apparatus of claim 58, wherein the electrical response of the chemically / electroactive material is measured upon exposure to the multi-component gas mixture only.   59. The apparatus of claim 58, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component.   59. The apparatus of claim 58, further comprising means for measuring the temperature of the gas mixture and means for digitizing the electrical response and temperature measurement.   59. The apparatus of claim 58, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 59. The apparatus of claim 58, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to b) resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 59. The apparatus of claim 58, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   59. The apparatus of claim 58, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current. The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device 59. The apparatus of claim 58, comprising: A multi-component gas mixture analyzer comprising:
(A) each chemically / electroactive material exhibits an electrical response characteristic different from that of each of the other chemically / electroactive materials upon exposure to the gas mixture at a selected temperature; An array of at least two chemically / electroactive materials, the electrical response characteristic of which can be quantified as a value, wherein the value of the response of the material to the gas mixture for a period of at least about 1 minute at the selected temperature An array that is constant during exposure of the material or changes by no more than about 20 percent;
(B) means for measuring the electrical response of each chemically / electroactive material individually upon exposure of the array to the gas mixture;
(C) means for measuring the temperature of the gas mixture;
(D) an apparatus comprising: means for digitizing the electrical response and temperature measurement.   72. The apparatus of claim 71, wherein the array is placed in a gas mixture and the gas mixture has a temperature of about 400 degrees Celsius or higher.   72. The apparatus of claim 71, wherein the gas mixture is exhaust gas from a combustion process.   72. The apparatus of claim 71, wherein the component gases in the gas mixture are not separated.   72. The apparatus of claim 71, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable.   72. The apparatus of claim 71, wherein the electrical response of the chemically / electroactive material is measured upon exposure to the multicomponent gas mixture only.   72. The apparatus of claim 71, further comprising means for calculating a concentration in the gas mixture of at least one individual gas component. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 72. The apparatus of claim 71, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to resistance before exposure.   72. The apparatus of claim 71, wherein the electrical response is selected from the group consisting of resistance, impedance, capacitance, voltage or current.   72. The apparatus of claim 71, wherein the array is placed in a gas mixture having a temperature less than about 400 degrees Celsius, and the array has a substantially constant temperature of about 400 degrees Celsius or higher.   72. The apparatus of claim 71, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the electrical response to control the process or device 72. The apparatus of claim 71, comprising: An apparatus for calculating the concentration of at least two individual analyte gas components in a multi-component gas mixture having a temperature of about 400 ° C. or higher comprising:
(A) an array of at least three chemically / electroactive materials, wherein an array is placed in the gas mixture and each chemically / electroactive material exhibits a change in electrical resistance upon exposure to the gas mixture, wherein at least When one chemically / electroactive material is at a temperature of about 400 ° C. or higher, (i) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm, and (ii ) An array that exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to the gas mixture as compared to resistance before exposure;
(B) means for measuring the change in resistance of each chemically / electroactive material individually upon exposure of the array to unseparated components of the gas mixture;
(C) means for calculating the concentration of individual analyte gas components from the change in resistance of the chemical / electroactive material upon exposure to the multi-component gas mixture alone.   84. The apparatus of claim 83, wherein the gas mixture is exhaust gas from a combustion process.   84. The apparatus of claim 83, further comprising means for measuring the temperature of the gas mixture, and wherein the concentrations of the individual gas components are calculated from the change in resistance of the chemically / electroactive material and the temperature measurement.   84. The apparatus of claim 83, wherein the temperature of each chemically / electroactive material is substantially measured only by the temperature of the gas mixture being variable.   The change in resistance of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the resistance value of the material is at a selected temperature for a period of at least about 1 minute. 84. The apparatus of claim 83, wherein the apparatus is constant during exposure of the material to the gas mixture or varies by no more than about 20 percent.   The apparatus of claim 83, wherein the at least one chemically / electroactive material is a metal oxide.   The multi-component gas mixture is the product of a chemical reaction that is exhausted by the process or sent to the device, and the apparatus further includes means for utilizing the change in resistance to control the process or device 84. The apparatus of claim 83, comprising: A gas detection device comprising an array of at least three chemically / electroactive materials, wherein each chemically / electroactive material exhibits a change in electrical resistance upon exposure to a multi-component gas mixture, wherein the at least one chemical / electroactive material When the material is at a temperature of about 400 ° C. or higher, (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm, and (b) resistance before exposure; In comparison, an apparatus that exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to the gas mixture.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 92. The apparatus of claim 91, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   92. The apparatus of claim 91, further comprising means for measuring the temperature of the array.   92. The apparatus of claim 91, wherein the at least one chemically / electroactive material is a metal oxide. Each chemical / electroactive material is exposed to other chemicals / exposures upon exposure to the multi-component gas mixture at the selected temperature.
A gas detection device comprising an array of at least two chemically / electroactive materials that exhibit different electrical response characteristics than each of the electroactive materials and that can be quantified as a certain value of the electrical response characteristics of at least one material. An apparatus wherein the value of the response of the material is constant during the exposure of the material to the gas mixture for a period of at least about 1 minute at the selected temperature or varies by no more than about 20 percent.   95. The apparatus of claim 94, further comprising means for measuring the temperature of the array.   95. The apparatus of claim 94, wherein the at least one chemically / electroactive material is a metal oxide. An array of chemically / electroactive materials wherein each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the multi-component gas mixture at a selected temperature. A gas detection device comprising, wherein at least one chemically / electroactive material is M ¹ O _x , M ¹ _a M ² _b O _x and M ¹ _a M ² _b M ³ _c O _x , wherein M ¹ Is selected from the group consisting of Ce, Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, Sc, Si, Sn, Sr, Ta, Ti, Tm, Selected from the group consisting of V, W, Y, Yb, Zn, and Zr, but M ² and M ³ are not the same in M ¹ _a M ² _b M ³ _c O _x and a, b and c are Each independently of about 0.0005 to about 1, and x is a number sufficient to balance the oxygen present with the charge of other elements in the compound) . (A) M ¹ O _x is Ce _a O _x , CoO _x , CuO _x , FeO _x , GaO _x , NbO _x , NiO _x , PrO _x , RuO _x , SnO _x , Ta _a O _x , TiO _x , TmO _x WO _x , YbO _x , ZnO _x , ZrO _x , SnO _x with Ag additive, ZnO _{x with} Ag additive, TiO _{x with} Pt additive, ZnO _x with frit additive, NiO _x with frit additive, SnO _{x with} frit additive, or Selected from the group consisting of WO _{x with} frit additive,
_{^{(B) M 1 a M 2}} b O x is _{Al a Cr b O x, Al} a Fe b O x, Al a Mg b O x, Al a Ni b O x, Al a Ti b O x, Al a V _{b O x, Ba a Cu b} O x, Ba a Sn b O x, Ba a Zn b O x, Bi a Ru b O x, Bi a Sn b O x, Bi a Zn b O x, Ca a Sn b O _x , Ca _a Zn _b O _x , Cd _a Sn _b O _x , Cd _a Zn _b O _x , Ce _a Fe _b O _x , Ce _a Nb _b O _x , Ce _a Ti _b O _x , Ce _a V _b O _{x, Co a Cu b O x} , Co a Ge b O x, Co a La b O x, Co a Mg b O x, Co a Nb b O x, Co a Pb b O x, Co a Sn b O x _{, Co a V b O x,} Co a W b O x, Co a _{n b O x, Cr a Cu} b O x, Cr a La b O x, Cr a Mn b O x, Cr a Ni b O x, Cr a Si b O x, Cr a Ti b O x, Cr a Y _{b O x, Cr a Zn b} O x, Cu a Fe b O x, Cu a Ga b O x, Cu a La b O x, Cu a Na b O x, Cu a Ni b O x, Cu a Pb b _{O x, Cu a Sn b O} x, Cu a Sr b O x, Cu a Ti b O x, Cu a Zn b O x, Cu a Zr b O x, Fe a Ga b O x, Fe a La b O _{x, Fe a Mo b O x} , Fe a Nb b O x, Fe a Ni b O x, Fe a Sn b O x, Fe a Ti b O x, Fe a W b O x, Fe a Zn b O x _{, Fe a Zr b O x,} Ga a La b O _{, Ga a Sn b O x,} Ge a Nb b O x, Ge a Ti b O x, In a Sn b O x, K a Nb b O x, Mn a Nb b O x, Mn a Sn b O x, Mna _a Ti _b O _x , Mna _a Y _b O _x , Mna _a Zn _b O _x , Mo _a Pb _b O _x , Mo _a Rb _b O _x , Mo _a Sn _b O _x , Mo _a Ti _b O _x , Mo _a Zn _b O _x , Nb _a Ni _b O _x , Nb _a Ni _b O _x , Nb _a Sr _b O _x , Nb _a Ti _b O _x , Nb _a W _b O _x , Nb _a Zr _b O _x , Ni _{a Si b O x, Ni a Sn} b O x, Ni a Y b O x, Ni a Zn b O x, Ni a Zr b O x, Pb a Sn b O x, Pb a Zn b O x, Rb a W _{b O x, Ru a Sn b} O x, Ru a W b _{x, Ru a Zn b O x} , Sb a Sn b O x, Sb
_{a Zn b O x, Sc a} Zr b O x, Si a Sn b O x, Si a Ti b O x, Si a W b O x, Si a Zn b O x, Sn a Ta b O x, Sn a _{Ti b O x, Sn a W} b O x, Sn a Zn b O x, Sn a Zr b O x, Sr a Ti b O x, Ta a Ti b O x, Ta a Zn b O x, Ta a Zr _{b O x, Ti a V b} O x, Ti a W b O x, Ti a Zn b O x, Ti a Zr b O x, V a Zn b O x, V a Zr b O x, W a Zn b O _x , W _a Zr _b O _x , Y _a Zr _b O _x , Zn _a Zr _b O _x , Al _a Ni _b O _x with frit additive, Cr _a Ti _b O _x with frit additive, Fe _a La with frit additive _b O _x, frit addition Monoiri e _a Ni _b O _x, frit added Monoiri _Fe a _Ti b _{O x,} frit added Monoiri _Nb a _Ti b _{O x,} frit added Monoiri _Nb a _W b _{O x,} frit added Monoiri _Ni a _Zn b _{O x,} frit added Monoiri Selected from the group consisting of Ni _a Zr _b O _x , Sb _a Sn _b O _x with frit additive, Ta _a Ti _b O _x with frit additive, or Ti _a Zn _b O _{x with} frit additive, and / or (c) _{^{M 1 a M 2 b M 3}} c O x is _{Al a Mg b Zn c O x} , Al a Si b V c O x, Ba a Cu b Ti c O x, Ca a Ce b Zr c O x, Co a _{Ni b Ti c O x, Co} a Ni b Zr c O x, Co a Pb b Sn c O x, Co a Pb b Zn c O x, Cr a Sr b _{Ti c O x, Cu a Fe} b Mn c O x, Cu a La b Sr c O x, Fe a Nb b Ti c O x, Fe a Pb b Zn c O x, Fe a Sr b Ti c O x, _{Fe a Ta b Ti c O x} , Fe a W b Zr c O x, Ga a Ti b Zn c O x, La a Mn b Na c O x, La a Mn b Sr c O x, Mn a Sr b Ti _{c O x, Mo a Pb b} Zn c O x, Nb a Sr b Ti c O x, Nb a Sr b W c O x, Nb a Ti b Zn c O x, Ni a Sr b Ti c O x, Sn _{a W b Zn c O x,} Sr a Ti b V c O x, Sr a Ti b Zn c O x, or _Ti a _W b _Zr c _{O x} system according to claim 97 which is selected from the group consisting of. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 98. The apparatus of claim 97, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to the resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 98. The apparatus of claim 97, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   98. The apparatus of claim 97, further comprising means for measuring the temperature of the array. First and second chemically / electroactive materials wherein each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to a multi-component gas mixture at a selected temperature A gas detection device comprising an array of: the chemically / electroactive material comprising:
(I) the first material is M ¹ O _x and the second material is M ¹ _a M ² _b O _x ;
(Ii) a first material is ^M 1 _{O x,} and the second material is _{^{M 1 a M 2 b M 3}} c O x,
(Iii) The first material is M ¹ _a M ² _b O _x , and the second material is M ¹ _a M ² _b M ³ _c O _x .
(Iv) the first material is first M ¹ O _x and the second material is second M ¹ O _x ;
(V) the first material is a first M ¹ _a M ² _b O _x and the second material is a second M ¹ _a M ² _b O _x ; and (vi) the first The material is a first M ¹ _a M ² _b M ³ _c O _x and the second material is a second M ¹ _a M ² _b M ³ _c O _x where M ¹ is Ce , Co, Cu, Fe, Ga, Nb, Ni, Pr, Ru, Sn, Ti, Tm, W, Yb, Zn, and Zr, and M ² and M ³ are each independently Al, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, In, K, La, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pr, Rb, Ru, Sb, sc, Si, Sn, Sr, Ta, Ti, Tm, V, W, Y, Yb, Zn, and is selected from the group consisting of Zr, ^{M 2} And ^{M 3} are not the same as in _{^{M 1 a M 2 b M 3}} c O x, a, b and c are from about 0.0005 to about 1 independently, and oxygen is the x is present Sufficient to balance the charge of other elements in the compound)
A device selected from pairing in the group consisting of: (A) M ¹ O _x is Ce _a O _x , CoO _x , CuO _x , FeO _x , GaO _x , NbO _x , NiO _x , PrO _x , RuO _x , SnO _x , Ta _a O _x , TiO _x , TmO _x , WO _x , YbO _x , ZnO _x , ZrO _x , SnO _x with Ag additive, ZnO _{x with} Ag additive, TiO _{x with} Pt additive, ZnO _x with frit additive, NiO _x with frit additive, SnO _{x with} frit additive, or Selected from the group consisting of WO _{x with} frit additive,
_{^{(B) M 1 a M 2}} b O x is _{Al a Cr b O x, Al} a Fe b O x, Al a Mg b O x, Al a Ni b O x, Al a Ti b O x, Al a V _{b O x, Ba a Cu b} O x, Ba a Sn b O x, Ba a Zn b O x, Bi a Ru b O x, Bi a Sn b O x, Bi a Zn b O x, Ca a Sn b O _x , Ca _a Zn _b O _x , Cd _a Sn _b O _x , Cd _a Zn _b O _x , Ce _a Fe _b O _x , Ce _a Nb _b O _x , Ce _a Ti _b O _x , Ce _a V _b O _{x, Co a Cu b O x} , Co a Ge b O x, Co a La b O x, Co a Mg b O x, Co a Nb b O x, Co a Pb b O x, Co a Sn b O x _{, Co a V b O x,} Co a W b O x, Co a _{n b O x, Cr a Cu} b O x, Cr a La b O x, Cr a Mn b O x, Cr a Ni b O x, Cr a Si b O x, Cr a Ti b O x, Cr a Y _{b O x, Cr a Zn b} O x, Cu a Fe b O x, Cu a Ga b O x, Cu a La b O x, Cu a Na b O x, Cu a Ni b O x, Cu a Pb b _{O x, Cu a Sn b O} x, Cu a Sr b O x, Cu a Ti b O x, Cu a Zn b O x, Cu a Zr b O x, Fe a Ga b O x, Fe a La b O _{x, Fe a Mo b O x} , Fe a Nb b O x, Fe a Ni b O x, Fe a Sn b O x, Fe a Ti b O x, Fe a W b O x, Fe a Zn b O x _{, Fe a Zr b O x,} Ga a La b O _{, Ga a Sn b O x,} Ge a Nb b O x, Ge a Ti b O x, In a Sn b O x, K a Nb b O x, Mn a Nb b O x, Mn a Sn b O x, Mna _a Ti _b O _x , Mna _a Y _b O _x , Mna _a Zn _b O _x , Mo _a Pb _b O _x , Mo _a Rb _b O _x , Mo _a Sn _b O _x , Mo _a Ti _b O _x , Mo _a Zn _b O _x , Nb _a Ni _b O _x , Nb _a Ni _b O _x , Nb _a Sr _b O _x , Nb _a Ti _b O _x , Nb _a W _b O _x , Nb _a Zr _b O _x , Ni _{a Si b O x, Ni a Sn} b O x, Ni a Y b O x, Ni a Zn b O x, Ni a Zr b O x, Pb a Sn b O x, Pb a Zn b O x, Rb a W _{b O x, Ru a Sn b} O x, Ru a W b _{x, Ru a Zn b O x} , Sb a Sn b O x, Sb a Zn b O x, Sc a Zr b O x, Si a Sn b O x, Si a Ti b O x, Si a W b O x _{, Si a Zn b O x,} Sn a Ta b O x, Sn a Ti b O x, Sn a W b O x, Sn a Zn b O x, Sn a Zr b O x, Sr a Ti b O x, _{Ta a Ti b O x, Ta} a Zn b O x, Ta a Zr b O x, Ti a V b O x, Ti a W b O x, Ti a Zn b O x, Ti a Zr b O x, V _{a Zn b O x, V a} Zr b O x, W a Zn b O x, W a Zr b O x, Y a Zr b O x, Zn a Zr b O x, frit added Monoiri _Al a _Ni b _{O x} , Cr _a Ti _b O _{x with} frit additive, Tsu DOO added Monoiri _Fe a _La b _{O x,} frit added Monoiri _Fe a _Ni b _{O x,} frit added Monoiri _Fe a _Ti b _{O x,} frit added Monoiri _Nb a _Ti b _{O x,} frit added Monoiri _Nb a _W b _{O x} , Ni _a Zn _b O _x with frit additive, Ni _a Zr _b O _x with frit additive, Sb _a Sn _b O _x with frit additive, Ta _a Ti _b O _x with frit additive, or Ti _a Zn _b O _x with frit additive It is selected from the group consisting of _x, and / or _{^{(c) M 1 a M 2}} b M 3 c O x is _{Al a Mg b Zn c O x} , Al a Si b V c O x, Ba a Cu b Ti c _{O x, Ca a Ce b Zr} c O x, Co a Ni b Ti c O x, Co a Ni
_{b Zr c O x, Co a} Pb b Sn c O x, Co a Pb b Zn c O x, Cr a Sr b Ti c O x, Cu a Fe b Mn c O x, Cu a La b Sr c O x _{, Fe a Nb b Ti c O} x, Fe a Pb b Zn c O x, Fe a Sr b Ti c O x, Fe a Ta b Ti c O x, Fe a W b Zr c O x, Ga a Ti b _{Zn c O x, La a Mn} b Na c O x, La a Mn b Sr c O x, Mn a Sr b Ti c O x, Mo a Pb b Zn c O x, Nb a Sr b Ti c O x, Nb _a Sr _b W _c O _x , Nb _a Ti _b Zn _c O _x , Ni _a Sr _b Ti _c O _x , Sn _a W _b Zn _c O _x , Sr _a Ti _b V _c O _x , Sr _a Ti _b Zn _c O _x or Ti, W _b Zr _c O _x The apparatus of claim 102 which is selected from the group consisting of. And (a) has an electrical resistivity in the range of about 1 ohm-cm to about 10 ⁶ ohm-cm when the at least one chemically / electroactive material is at a temperature of about 400 ° C. or higher; 105. The apparatus of claim 102, wherein the apparatus exhibits a change in electrical resistance of at least about 0.1 percent upon exposure of the material to a gas mixture as compared to b) resistance before exposure.   The electrical response characteristic of at least one material can be quantified as a value upon exposure to the gas mixture at a selected temperature, and the value of the material response is at a period of at least about 1 minute at the selected temperature. 105. The apparatus of claim 102, wherein the apparatus is constant during exposure of the material to the gas mixture of or changes by no more than about 20 percent.   The apparatus of claim 102, further comprising means for measuring the temperature of the array.   103. The array of claim 102, wherein the array comprises four or more chemically / electroactive materials and the device further comprises an electrode in contact with each member of the three groups of the chemically / electroactive materials. apparatus.   The array further comprises three or more chemically / electroactive materials and the device further comprises an electrode in contact with each member of the two groups of the chemically / electroactive material, through which the current is passed. 103. The device of claim 102, which is passed sequentially to each member of the group of two chemically / electroactive materials. A multi-component gas mixture analyzer comprising:
(A) an array of at least three chemically / electroactive materials, wherein each chemically / electroactive material exhibits different electrical response characteristics than each of the other chemically / electroactive materials upon exposure to the gas mixture;
(B) means for measuring the electrical response of each chemically / electroactive material upon exposure of the array to the gas mixture;
(C) (i) detecting the presence of a subgroup of gases in the mixture from the response of at least two chemically / electroactive materials of the first group; and (ii) at least two chemical / electrical groups of the second group. Means for detecting the presence of individual component gases in the mixture from the response of the active material.   110. The apparatus of claim 109, wherein the individual component gases are not constituents of a subgroup of gases.   110. The apparatus of claim 109, wherein none of the first group of chemically / electroactive materials is the same as any of the second group of chemically / electroactive materials.   110. The apparatus of claim 109, wherein the means for detecting further comprises means for calculating a concentration within a subgroup of gases, or individual component gases, or a mixture of both.   110. An internal combustion engine comprising an apparatus according to any one of claims 1, 13, 21, 27, 35, 45, 58, 71, 83, 90, 94, 97, 102 or 109.   110. A motor vehicle comprising the device according to any one of claims 1, 13, 21, 27, 35, 45, 58, 71, 83, 90, 94, 97, 102 or 109.

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