Abstract: The present disclosure relates to methods, devices, and systems for measuring nitric oxide released from a material. For example, a method of measuring nitric oxide release from a material can include introducing a continuous flow of a carrier gas into a sample holding chamber via a carrier gas inlet at an effective flow rate, introducing an amount of the nitric oxide releasing material into the sample holding chamber via a separate sample inlet to contact the continuous flow of the carrier gas, directing the carrier gas and released nitric oxide out of the sample holding chamber via a nitric oxide outlet toward a nitric oxide detector, and quantifying an amount of released nitric oxide using the nitric oxide detector.

Abstract: A gas sensor includes a main pump cell, a storage unit that stores information about a zero point in a first correspondence relationship, where the first correspondence relationship is a linear correspondence relationship between the oxygen concentration in a measurement-object gas and the main pump current, an oxygen-concentration-detecting unit that detects the oxygen concentration in a measurement-object gas, based on a measured value p of the main pump current and the information about the zero point, and a measured-value-obtaining unit that performs a second control process and that obtains a measured value b1 at a measurement point B1 at which a known value of the oxygen concentration and the main pump current are relevant to each other with a measurement timing. The oxygen-concentration-detecting unit makes zero point correction such that a divergence of the zero point from the first correspondence relationship is corrected based on the measured value b1.

Abstract: A device and method for calibrating a NO delivery device using NO and NO2 measurements, without using a known standard.

Abstract: Disclosed is an ammonia sensor element for detecting ammonia in a gas under measurement, including two mixed-potential-type ammonia detection cells that respectively include first and second ammonia detection electrodes. The first ammonia detection electrode has a metal composition containing Au as a predominant component. The second ammonia detection electrode has a metal composition containing Au as a predominant component. The metal compositions of the first and second ammonia detection electrodes are different from each other.

Abstract: A fluid catalytic cracking (FCC) unit for the production of hydrocarbon products includes a fluid injection system coupled to a reactor by a standpipe. The fluid injection system includes a plurality of nozzles for injecting oil feedstock into the standpipe to react with a catalyst flowing therethrough.

Abstract: A microcomputer calculates the concentration of ammonia contained in exhaust gas. The microcomputer repeatedly obtains from a first ammonia detection section a first ammonia electromotive force EMF1 whose value changes with both the concentrations of ammonia and a flammable gas contained in the exhaust gas. The microcomputer outputs, as ammonia concentration information at the present point in time, ammonia concentration information representing the ammonia concentration at the point 0.5 sec prior to the present point in time. The microcomputer sets a rich spike flag Fs when a first ammonia electromotive force change amount ?EMF1 is smaller than a value obtained by multiplying a start determination value by ?1. When the rich spike flag Fs is set, the microcomputer sets the ammonia concentration information at the present point in time to the value of the ammonia concentration information at the point immediately before the rich spike flag Fs is set.

Abstract: A sensor controller includes a signal reception determination section and a use suspension section. The signal reception determination section determines whether or not the sensor controller has received a specific state signal that indicates a specific state in which exhaust gas may contain a specific gas that differs from ammonia and reacts with an ammonia sensor. When the signal reception determination section determines that the sensor controller has received the specific state signal, the use suspension section suspends at least temporarily use of a detection result detected by the ammonia sensor after the determination. Specifically, upon reception of the specific state signal, the sensor controller suspends at least temporarily the use of the detection result detected by the ammonia sensor after the reception of the specific state signal.

Abstract: A sensor system includes a common gas chamber and a reference gas chamber respectively configured to receive an exhaust gas and a reference gas. A Nernst cell is exposed to the common gas chamber and the reference air chamber. The Nernst cell provides a reference signal indicative of an oxygen difference between the common gas chamber and the reference air chamber. An oxygen electrochemical pump cell is exposed to the common gas chamber and exhaust gas and provides an oxygen signal indicative of an oxygen only concentration. A NOx electrochemical cell is exposed to the common gas chamber and provides a NOx signal indicative of a NOx concentration. A processor is in communication with the Nernst cell, the oxygen-only electrochemical pump cell and NOx electrochemical cells. The processor outputs oxygen and NOx signals and provide a NOx concentration and oxygen concentration of the exhaust.

Abstract: An electrochemical gas sensor (10) includes a housing (11) which has a number of electrodes (31, 32), i.e. at least one working electrode (31) and at least one counter electrode (32), in addition to a liquid electrolyte (60). At least one of the electrodes (31, 32) and/or the housing (11) are at least partially formed of an absorption agent composition. A method of detecting acid gases employs the electrochemical gas sensor (10).

Abstract: Disclosed herein are embodiments of a gas sensor system and methods of analyzing data therefrom. In embodiments, a gas sensor system includes one or more gas preconcentrator modules and one or more gas sensor modules. Each gas preconcentrator module includes a substrate that has a top surface having a gas adsorbent material attached to the top surface and has an electrical heater element for heating each preconcentrator module to release adsorb gases to the sensor. The gas sensor modules and the gas preconcentrator modules are in fluid communication with each other. The gas sensor modules responses are readout in parallel multiple times as the preconcentrators are heated yielding a 2-dimensional gas spectrum. The gas sensor output data is analyzed and compared to a library of known data to analyze the gas composition.

Abstract: Amount of combined nitric oxide or nitric oxide presented as iron nitrosyls in a blood sample is determined by directing a low power electromagnetic radiation beam at a blood sample to liberate nitric oxide gas, dissolving the liberated nitric oxide gas and electrochemically detecting amount of dissolved nitric oxide gas.

Abstract: Provided is a gas sensor capable of accurately obtaining a hydrocarbon gas concentration even if a measurement gas contains water vapor. A main pumping cell adjusts an oxygen partial pressure of a first internal space such that a hydrocarbon gas in a measurement gas is not substantially burned in the first internal space. An auxiliary pumping cell adjusts an oxygen partial pressure of a second internal space such that inflammable gas components except for hydrocarbon are selectively burned. Then, the measurement gas is introduced into a third internal space through a third diffusion control part. With oxygen concentration equilibrium kept in the third internal space, hydrocarbon existing in the measurement gas that has reached the third internal space is all burned. Then, the concentration of the hydrocarbon gas component existing in the measurement gas is identified based on the magnitude of a current flowing between the measuring electrode and the main pumping electrode at that time.

Abstract: A control system includes an upstream nitrogen oxide (NOx) control module that increases an upstream NOx level based on an initial upstream NOx level in an exhaust system, and an ammonia (NH3) storage condition detection module that detects a NH3 storage condition based on a difference in a downstream NOx level before and after the upstream NOx level is increased. A method includes increasing an upstream NOx level based on an initial upstream NOx level in an exhaust system, and detecting an NH3 storage condition based on a difference in a downstream NOx level before and after the upstream NOx level is increased.

Abstract: Molecularly imprinted conducting polymer (MICP) films were electro-polymerized on glassy carbon electrode having specific recognition sites for amino acid viz. L-tyrosine and/or L-cysteine. The amino acid templates in various imprinted films were ejected out by over-oxidation followed by washing and stabilization. Again, the template leached MICP films were modified with metal oxides [oxides of Cu2+, Hg2+, Pd2+, Au3+, Pt4+ etc]. The resultant leached MICP and metal oxide modified template leached MICP film based GCE will now selectively sense L-tyrosine and/or L-cysteine in aqueous media by direct and catalytic means respectively employing differential pulse voltammetric waveform. The sensitivity and selectivity of the sensors prepared by the invention are high and the stability is good, which will be widely used in clinical diagnostics, chemical industry, environment protection and other related fields.

Abstract: A gas sensor processing apparatus (1) which includes voltage shift means (11, 19, S1071) for shifting a detection element voltage VE produced between electrodes (3P, 3N) of a detection element (3) from a pre-shift voltage VE1 to a post-shift voltage VE2; recovery means (11, 19, S1072) for returning the detection element voltage VE from the post-shift voltage VE2 to the pre-shift voltage VE1 after the end of a voltage shift period TS in which the voltage VE is shifted by the voltage shift means; and deterioration index detection means S106-S107 for detecting a deterioration index ID representing the degree of deterioration of the detection element (3) on the basis of a voltage change in the recovery period TK in which the voltage VE is recovered by the recovery means.

Abstract: Electrode configurations for electric-field enhanced performance in catalysis and solid-state devices involving gases are provided. According to an embodiment, electric-field electrodes can be incorporated in devices such as gas sensors and fuel cells to shape an electric field provided with respect to sensing electrodes for the gas sensors and surfaces of the fuel cells. The shaped electric fields can alter surface dynamics, system thermodynamics, reaction kinetics, and adsorption/desorption processes. In one embodiment, ring-shaped electric-field electrodes can be provided around sensing electrodes of a planar gas sensor.

Abstract: A handheld, small but accurate and reliable device for diagnostic NO measurements using a NO sensor, where the parameters governing the taking of the sample are different from the parameters optimal for the accuracy of said NO sensor. By temporarily storing a portion of the exhaled air, and feeding this to the sensor at a flow rate adapted to the NO sensor, the accuracy and sensitivity of a system/method involving NO sensors, in particular electrochemical NO sensors, can be increased. The method for diagnostic NO measurements comprises steps for controlling the inhalation of NO free air, as well as the exhalation, both by built-in means and by audible and/or visual feedback to the patient.

Abstract: A chronoamperometric method and device to determine concentration of an electrochemically active species in a fluid and pH of the fluid. A plurality of sets of calibration relationships may be determined for a sensor in an aqueous solution, the sensor having one or more working electrodes and one or more reference electrodes. A first plurality of potentials may be applied across the working and reference electrodes of the sensor in solution, and a first plurality of currents and current differences obtained as a function of the applied first plurality of potentials. Concentration of an electrochemically active species may then be determined as a function of the obtained first plurality of currents and current differences using the plural sets of calibration relationships, and pH of the solution may be determined as a function of the obtained first plurality of currents and current differences using the plural sets of calibration relationships.

Abstract: Various systems, devices, NO2 absorbents, NO2 scavengers and NO2 recuperator for generating nitric oxide are disclosed herein. According to one embodiment, an apparatus for converting nitrogen dioxide to nitric oxide can include a receptacle including an inlet, an outlet, a surface-active material coated with an aqueous solution of ascorbic acid and an absorbent wherein the inlet is configured to receive a gas flow and fluidly communicate the gas flow to the outlet through the surface-active material and the absorbent such that nitrogen dioxide in the gas flow is converted to nitric oxide.

Abstract: Disclosed is a gas sensor, particularly a lambda probe, for determining the oxygen concentration in the exhaust gas of an internal combustion engine that is operated using a fuel-air mixture. Said gas sensor comprises a pump cell with an outer electrode that is exposed to the exhaust gas, an inner electrode located in a measuring chamber which is separated from the exhaust gas by means of a first diffusion barrier, and an electronic circuit for generating a voltage applied between the outer electrode and the inner electrode as well as for measuring and evaluating a pump current that is generated in said process in order to draw a conclusion therefrom about the composition of the fuel-air mixture.

Abstract: A method of processing a sensor element includes the steps of: (a) preparing a gas atmosphere containing hydrocarbon, having an air-fuel ratio of 0.80 to 0.9999, and having a small amount of oxidizing gas added thereto; and (b) subjecting a sensor element to a heat treatment in the gas atmosphere at a temperature of 500° C. or higher for 15 minutes or longer. The sensor element includes an electrochemical pumping cell constituted of an oxygen-ion conductive solid electrolyte and an electrode having a NOx reduction ability. A NOx gas in a measurement gas is reduced or decomposed in the electrode. A NOx concentration in the measurement gas is obtained based on a current which flows in the electrochemical pumping cell at a time of the reduction or decomposition.

Abstract: A method for measuring and/or calibrating a gas sensor for determining oxygenic gas components in gas mixtures in exhaust gases of internal combustion engines. The gas sensor has one internal pump electrode IPE, one external pump electrode APE and one decomposition electrode NOE. The measurement and/or calibration may be carried out during the ongoing operation of the gas sensor by removing the gas component and/or oxygen from one of the chambers, by introducing oxygen in a controlled manner into one of the chambers with the aid of electrochemical pumping processes. The changes caused by the introduced oxygen are measured against an additional electrode and the gas sensor may be measured and/or calibrated using the measured values.

Abstract: Apparatus and methods in accordance with one or more preferred embodiments of the present invention are used to measure nitric oxide in a fluid, and each includes a sample injection port; a pump; a measurement chamber; an electromagnetic radiation source; one or controls and user interfaces; and a cartridge. The cartridge includes a sample chamber; an electromagnetic radiation and heat chamber; and a gas permeable membrane. The cartridge preferably is single-use and disposable. Further apparatus and methods in accordance with other alternative embodiments, and additional inventive aspects and features, are disclosed related to measuring nitric oxide in a fluid.

Abstract: An exemplary apparatus for measuring nitric oxide in a fluid includes a sample injection port; a pump and reservoir; a valve; a measurement chamber; an electromagnetic radiation source; controls and user interface; and a cartridge. The cartridge includes a sample chamber a mix chamber; a sample degassing chamber; and a planar reaction chamber. The cartridge preferably is single-use and disposable. Furthermore, additional inventive aspects and features are disclosed related to measuring nitric oxide in a fluid.

Abstract: An electrochemical test strip is formed from a first insulating substrate layer, a second substrate layer, and an intervening insulating spacer layer. An opening in the insulating spacer layer defines a test cell which is in contact with the inner surface of the first substrate on one side and the inner surface of the second substrate on the other side. The size of the test cell is determined by the area of substrate exposed and the thickness of the spacer layer. Working and counter electrodes appropriate for the analyte to be detected are disposed on the first insulating substrate in a location within the test cell. The working and counter electrodes are associated with conductive leads that allow The second substrate is conductive at least in a region facing the working and counter electrodes. No functional connection of this conductive surface of the second substrate to the meter is required.

Abstract: A gas-phase detection system based on detecting optochemical and optoelectrochemical signals. The sensing platform is particularly powerful for detection of nitrogen oxides at low ppbV concentrations. The optochemical analysis is based on the color development due to a chemical reaction taking place in an optimized material. The electrochemical analysis can be based on the doping level or redox potential changes of an electrochemical sensor; and optoelectrochemical detection can be based on a combination of the electrochemical and optoelectrochemical methodologies. Each independent signal can be simultaneously detected, increasing the reliability of detection.

Abstract: The presently disclosed subject matter relates to sensors for measuring an amount of a gaseous species in a sample. The sensors comprise a gas permeable polysiloxane network membrane, comprising both alkyl and fluorinated alkyl groups. In some embodiments, the polysiloxane network can be formed from the co-condensation of a mixture of an alkylalkoxysilane and a fluorosilane. The presently disclosed subject matter also relates to methods of making the sensors, methods of selectively measuring an amount of a gaseous species, such as nitric oxide, in a sample, and to compositions comprising the polysiloxane networks.

Abstract: An electrochemical gas sensor includes: a disc-shaped metal bottom member; a cylindrical metal side member that extends along the axial direction of the bottom member to surround the bottom member; a ring-shaped polymer gasket that includes an opening in the center and in which both sides of the opening each have an L-shaped member in cross section, with one section of the L-shaped member being in contact with the inner side of the side member and the other section of the L-shaped member being in contact with the bottom member; a gas sensor body that is located in the opening of the gasket and whose bottom surface is in contact with the bottom member and that includes a pair of electrodes and a solid electrolyte membrane or a separator retaining a liquid electrolyte; and a metal cover that is in contact with the top surface of the gas sensor body.

Abstract: An amperometric electrochemical sensor configured to be operable in an oxidizing atmosphere and under an applied bias to exhibit enhanced reduction of oxygen molecules at the sensing electrode in the presence of one or more target gas species and a resulting measurable increase in oxygen ion flux through the cell. The sensor has an electrolyte membrane, a sensing electrode on the electrolyte membrane, and a counter electrode on the electrolyte membrane, wherein the sensing electrode includes at least one molybdate or tungstate compound. An electrochemical sensor system is also provided, along with a method of detecting the concentration of one or more of NOx and NH3 in a gas sample or stream.

Abstract: The present disclosure relates to a gas sensor, including: a gas collecting chamber including: (a) a nanoporous wall including alumina, on a portion of the gas collecting chamber in the near vicinity of the solid propellant fuel; a micro pump attached to the gas collecting chamber; and a gas analysis device connected to the gas collecting chamber. The gas analysis device measures both type and concentration of gases collected in the gas collecting chamber via the nanoporous wall, the gases measured being selected from the group consisting of CO, CO2, NO, N2O, NO2 and combinations thereof. The present disclosure also relates to a method of sensing propellant degradation in solid fuel and a method of using a gas collecting chamber to sense such degradation.

Abstract: A method for detecting at least one property of a gas in a measuring gas chamber, in particular for detecting at least one gas component of the gas. The at least one property is determined using at least one electrochemical measuring cell of a sensor element. Temperatures are detected at at least two different locations of the sensor element and used in determining the at least one property.

Abstract: A NOx sensor includes a sensor element equipped with first and second pumping cells to define first and second measurement chambers. The first pumping cell exerts an oxygen pumping action against the first measurement chamber to adjust the oxygen concentration in the gas under measurement within the first measurement chamber to a given level. The second pumping cell exerts an oxygen pumping action against the second measurement chamber to produce a pumping cell current according to the NOx concentration in the gas under measurement. When the moisture content of the gas under measurement changes from 2 vol % to 8 vol %, the NOx sensor allows a variation of NOx concentration detection value based on the pumping cell current in such a manner that the NOx concentration detection value reaches a transient peak value of 20 ppm or smaller and converges to ±5 ppm of a reference value within 5 seconds.

Abstract: Described herein are antibodies, and antigen-binding fragments thereof, that are specific for folate receptor alpha, related polynucleotides, expression vectors, and cells that express the described antibodies. Also provided are methods of using the described antibodies, and antigen-binding fragments thereof, and related kits. Provided herein are also methods for diagnosing cancers, such as breast cancer, thyroid cancer, colorectal cancer, endometrial cancer, fallopian tube cancer, ovarian cancer, or lung cancer, using the described antibodies, and antigen-binding fragments thereof. The methods involve determining the amount of folate receptor alpha in a sample derived from a subject and comparing this level with the level of folate receptor alpha in a control sample or reference sample.

Abstract: A primary pump current is directed through a primary electrochemical cell system between first and second constant primary pump currents to direct a first ion flow into and out from a shared measuring chamber. A first output signal generated by the primary electrochemical cell system in accordance with a first ion concentration within the shared measuring chamber is detected. A second output signal generated by a secondary electrochemical cell system in accordance with a second ion concentration within the shared measuring chamber is also detected. Based on a relationship between the first and second output signals, a secondary pump current is directed through the secondary electrochemical cell system between first and second constant secondary pump currents to direct a second ion flow into and out from the shared measuring chamber.

Abstract: A method for detecting nitrogen oxides, the method comprising monitoring the change in potential difference between a working electrode and a reference electrode as the working electrode is exposed to nitrogen oxides, where the working electrode includes an inorganic non-metallic oxide selected from spinel-structured compounds and wolframite-structured compounds, and where the working electrode and the reference electrode are in contact with a solid electrolyte.

Abstract: The gas sensor includes a sensor element having electrode pads formed in its electrode forming surfaces at the proximal end portion thereof, an insert-holding insulator insert-holding the sensor element, a housing insert-holding the insert-holding insulator, and a terminal unit. The proximal end portion of the sensor element is held by the terminal unit which includes a pair of proximal end insulators formed with metal terminals at their inner surfaces, and a spring member pressing the proximal end insulators in a direction that they approach each other. Each of the proximal end insulators includes an insulator contact portion in contact with one of the electrode forming surfaces. The insulator contact portion is located closer to the proximal end of the sensor element than a terminal contact portion at which the metal terminal contacts a corresponding one of the electrode pads.

Abstract: A gas sensor control apparatus including internal resistance detection means for detecting an internal resistance value of one of cells of a gas sensor, concentration detection means for detecting a concentration value of a specific gas component in a gas to be measured and outputting the detected concentration value, heater current supply control means for controlling a current to be supplied to a heater of the gas sensor such that the detected internal resistance value becomes a target value, determination means for determining whether or not the detected internal resistance value is within a permissible range including the target value, nullification information generation means for generating nullification information to nullify the detected concentration value, when it is determined that the target value is out of the permissible range, and nullification information output means for outputting the nullification information to an external device connected to the gas sensor control apparatus.

Abstract: A gas sensor including a detection element having a stacked structure configured to detect a specified gas component contained in a gas to be detected. The detection element includes: a sensing portion including one or more solid electrolyte layers containing a first material as a main component and having a first surface and a second surface opposite the first surface; a first portion stacked on the first surface and including one or more first base layers containing a second material as a main component different from the first material; and a second portion stacked on the second surface and including one or more second base layers containing the second material. A total thickness of the one or more second base layers in a stacking direction is not less than 80% but not more than 120% of a total thickness of the one or more first base layers.

Abstract: A mixed potential NOx sensor apparatus for measuring the total NOx concentration in a gas stream is disclosed. The NOx sensing apparatus comprises a multilayer ceramic structure with electrodes for sensing both oxygen and NOx gas concentrations and includes screen-printed metallized patterns that function to heat the ceramic sensing element to the proper temperature for optimum performance. This design may provide advantages over the existing technology by miniaturizing the sensing element to provide potentially faster sensor light off times and thereby reduce undesired exhaust gas emissions. By incorporating the heating source within the ceramic sensing structure, the time to reach the temperature of operation is shortened, and thermal gradients and stresses are minimized. These improvements may provide increased sensor performance, reliability, and lifetime.

Abstract: A gas sensor control apparatus including internal resistance detection means for detecting an internal resistance value of one of cells of a gas sensor, concentration detection means for detecting a concentration value of a specific gas component in a gas to be measured and outputting the detected concentration value, heater current supply control means for controlling a current to be supplied to a heater of the gas sensor such that the detected internal resistance value becomes a target value, determination means for determining whether or not the detected internal resistance value is within a permissible range including the target value, and nullification setting means for setting the detected concentration value to a predetermined nullification concentration value to nullify the detected concentration value, when it is determined that the target value is out of the permissible range.

Abstract: Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (110, 120), wherein the exhaust gas to be measured is supplied to the first measuring chamber (110) and an oxygen concentration is set by means of a first oxygen ion pump current (IP1), wherein the second measuring chamber (120) is connected to said first measuring chamber (110) and wherein both measuring chambers are disposed in a solid electrolyte, the oxygen content in the second measuring chamber (120) is determined; the oxygen content is additionally determined by a separate device; the two values characterizing the oxygen concentration are compared and a defective sensor is then suggested if the oxygen concentration value determined in the second measuring chamber (120) deviates from the oxygen concentration value determined by the separate sensor device by a predeterminable magnitude.

Abstract: A method and apparatus for controlling a multi-gas sensor, including an NOX sensor section and an ammonia sensor section. The NOX sensor section includes a first pumping cell adapted to pump oxygen into or out of a gas under measurement introduced into a first measurement chamber, and a second pumping cell communicating with the first measurement chamber and configured such that a second pumping current Ip2 corresponds to an NOX concentration of the gas under measurement. Oxygen concentration is calculated on the basis of a first pumping current flowing through the first pumping cell, and a corrected ammonia concentration is calculated on the basis of the oxygen concentration and the ammonia concentration output of the ammonia sensor section.

Abstract: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.

Abstract: A system for sensing and communicating in a pipeline that contains a fluid. An acoustic signal containing information about a property of the fluid is produced in the pipeline. The signal is transmitted through the pipeline. The signal is received with the information and used by a control.

Abstract: A gas sensor for measuring NOx concentration in measurement gas based on sensor output depending on an amount of the detected oxygen includes an oxygen concentration control part for controlling oxygen concentration in the measurement gas. The oxygen concentration control part allows a control of oxygen concentration in the measurement gas to set at a designated value even after being mounted on an automobile, so that dependency of the sensor output with respect to oxygen concentration can be quantitatively detected. The sensor output for detecting NOx concentration is corrected by estimating an amount of a change accompanying the sensitivity degradation of the sensor output with respect to NOx concentration on the basis of a difference between oxygen output characteristics of the sensor output of an actually-used sensor and oxygen output characteristics of a sensor in the initial state, and correcting the sensor output in accordance with the amount of the change.

Abstract: There is provided a gas sensor, which includes a sensor element extending axially of the gas sensor and having a gas sensing portion at a front end thereof and an electrode portion at a rear end thereof, a cylindrical metal shell retaining therein the sensor element with the gas sensing portion and the electrode portion protruding from front and rear ends of the metal shell, respectively, and having a flange portion and a rear end portion located on a rear side of the flange portion, a cylindrical protection cover having a front end fitted onto the rear end portion of the metal shell so as to cover the electrode portion and a weld joint through which the entire circumference of the front end of the protection cover is joined through the metal shell. The weld joint extends from an end face of the protection cover to the metal shell.

Abstract: An apparatus and method for individually detecting NO and NO2 concentrations as NOX components of an object gas. An NO concentration corresponding value is obtained from a first detection element not having a reduction section. An NO concentration corresponding value is obtained from a second detection element having a reduction section, and having an NO2/NO sensitivity ratio greater than that of the first detection element. The difference ?C between the NO concentration corresponding values of the two detection elements is obtained, and divided by the difference ?S between the NO2/NO sensitivity ratios of the two detection elements, whereby an NO2 concentration corresponding value is obtained. A value obtained by multiplying the NO2 concentration corresponding value by the NO2/NO sensitivity ratio of the second detection element is subtracted from the NO concentration corresponding value of the second detection element, whereby an NO concentration corresponding value is obtained.

Abstract: A gas measuring system, having a measurement sensor (1) which records an exhaust gas from an internal combustion engine and has an outer electrode (6), which is exposed to the exhaust gas to be measured, a first measuring cell (4), a second measuring cell (8) that is connected to the first measuring cell (4), and in which a measuring electrode (10) is arranged, and a reference electrode (11) that is exposed to the ambient air. The measuring cells (4, 8) are located in a solid electrolyte (2), and all the electrodes (10, 11) are in contact with the solid electrolyte.

Abstract: A method of correcting NOx sensor includes the steps of preparing a corrective map in advance, finding an existing proportion of NO or NO2 in a mixture of NOx in exhaust gases before coming into an NOx sensor, and correcting an NOx concentration that the NOx sensor detects actually. The corrective map records relationships between temperature physical quantities that are relevant to a temperature of the exhaust gases, oxygen-concentration physical quantities that are relevant to an oxygen concentration in the exhaust gases, and the existing proportion. The existing proportion is found with reference to the corrective map using the temperature physical quantities and oxygen-concentration physical quantities that are detected actually. The NOx concentration is corrected on the basis of not only the existing proportion but also a difference between an NO2 diffusion velocity and an NO diffusion velocity.

Abstract: A low cost room temperature electrochemical gas sensor with humidity compensation for sensing CO, alcohol vapors and other toxic analyte gases has a solid protonic conductive membrane with a low bulk ionic resistance. A sensing electrode and a counter electrode, optionally a counter electrode and a reference electrode, which are separated by the membrane, can be made of mixed protonic-electronic conductors, or can be made of a thin electrically conducting film such as platinum. A reservoir of water maintain the solid protonic conductive membrane at constant 100 percent relative humidity to compensate for ambient humidity changes. Embodiments of the inventive sensor also include an electrochemical analyte gas pump to transport the analyte gas away from the counter electrode side of the sensor.