Abstract: A measurement circuit may include a transistor having a first terminal, a second terminal, and a third terminal, wherein the first terminal is coupled to a first reference voltage. The measurement circuit may further include a first operational amplifier including a first input coupled to the second terminal of the transistor and an output coupled to the third terminal of the transistor. The first operational amplifier may further include a second input configured to receive a second reference voltage. The measurement circuit may also include a first unity-gain voltage follower including a second operational amplifier having a first input coupled to the first input of the first operational amplifier. Methods of measuring a threshold voltage, semiconductor devices, and electronic systems are also described.

Abstract: The present invention relates generally to components prepared by additive manufacturing (AM) methods, along with methods of preparing such components by AM. More especially, there is provided a process for the production of a component of an ignition device using an AM method by forming a layer of metal or alloy on a surface of a metal or alloy substrate; fusing the layer to the substrate; and repeating the addition of such layers upon one another to form a deposited metal or alloy attachment on the substrate.

Abstract: A system includes a system housing including an inlet, at least one gas sensor responsive to a first analyte gas other than oxygen within the system housing and in fluid connection with the inlet, and a sensor responsive to oxygen within the system housing and in fluid connection with the inlet. The sensor responsive to oxygen is formed to be chemically separate from the at least one gas sensor responsive to the first analyte gas other than oxygen. The sensor responsive to oxygen is responsive to a change in the concentration of oxygen arising from creation of a driving force in the vicinity of the inlet to provide an indication of a state of a transport path between the inlet of the system and the at least one gas sensor responsive to the first analyte gas other than oxygen.

Abstract: An apparatus is described. The apparatus includes a first portion having a first material and a first interface surface. A second portion having a second material that is different than the first material is included. The second portion has a second interface surface that is connected to the first interface surface of the first portion. A method of manufacturing an apparatus is described. The method includes adhering a first portion of the apparatus to a second portion of the apparatus to create a combined portion. After adhering the first portion of the apparatus to the second portion of the apparatus to create the combined portion, the combined portion of the apparatus is treated.

Abstract: An electrochemical sensor may include a common reference electrode, at least one counter electrode, and a work electrode platform including a plurality of respective work electrodes. Each respective work electrode of the plurality of respective work electrodes may be electrically coupled to the common reference electrode and include a respective reagent substrate configured to react with a respective analyte to produce a signal indicative of a concentration of the respective analyte.

Abstract: The invention provides an energy generation and/or conversion system and method wherein an electrical power generator is controlled to periodically alternate between a contact-mode, during which elements of the generator are brought into contact to induce a state of charging, and a non-contact mode, during which plates of the generator are separated from one another and electrical energy is generated through electrostatic induction. Timing and duration of contact and non-contact modes are controlled by a controller, or by user commands, in dependence on a charge state of the elements of the generator: In this way elements are controlled to come into contact only when surface charge has fallen below a certain level, and re-charging is necessary; contact time between the elements may hence be minimised—thereby minimising incurred noise and surface wear—whilst still maintaining a given desired threshold power output.

Abstract: A sensor for sensing gaseous chemicals includes a substrate, a variable resistance nanocrystalline ITO thin film formed on the substrate, and electrodes electrically coupled to the thin film. A sensor array assembly includes a sensor slide and a perforated interface circuit. The interface circuit abuts and electrically couples the sensor slide. The sensor slide includes several spaced apart ITO film strips formed on a slide substrate. A common electrode is electrically coupled to a common portion of each ITO film strip providing an electrically conductive path across the common portions of each of the plurality of spaced apart ITO film strips. A discrete electrode is electrically coupled to a discrete portion of each ITO film strip. The interface circuit is configured to abut and electrically couple to the sensor slide. A conductive discrete electrode pad electrically couples each of the plurality of discrete electrodes of the sensor slide to discrete terminals on the interface circuit.

Abstract: An electrochemical metal alloy identification device employing electrolytes to measure and identify different potentials of alloys is presented. This includes physical structure, disposables, electrical systems, control circuitry, and algorithms to identify alloys.

Abstract: There are provided a sensor substrate and a sensor device which have high detection accuracy. A sensor substrate includes an insulating substrate; sensing electrodes disposed in the insulating substrate, the sensing electrodes being columnar and being composed of at least one pair of positive and negative sensing electrodes, in the at least one pair of positive and negative sensing electrodes, part of a positive electrode and part of a negative electrode being each exposed from one surface of the insulating substrate; and innerlayer wiring lines embedded within the insulating substrate, the innerlayer wiring lines corresponding to the positive electrode and the negative electrode, respectively, in the at least one pair of positive and negative sensing electrodes.

Abstract: Disclosed are devices, systems and methods for assessing the integrity of electrical connections between elements of interfacing electronic devices. In some aspects, a system includes an analysis device having electronics that interface with an assay cartridge inserted into the analysis device, wherein the analysis device is configured to conduct a preflight test in which impedance values for each circuit between the assay cartridge and analysis device are rearranged and assessed to determine the electrical connection integrity of the assay cartridge to the analysis device prior to implementing the assay.

Abstract: Compensator circuitry is provided for an oxygen sensor which includes a pump cell and a reference cell. The compensator circuitry includes a feedback control loop which maintains the reference cell at a reference voltage. The feedback control loop includes a digital compensator which determines and outputs a compensation current to the pump cell dependent on a reference voltage measured from the reference cell. The digital compensator also suspends the determination and output of the compensation current for a set time which is dependent on detection of edges in an oxygen sensor heater Pulse Width Modulation signal.

Abstract: An air-fuel ratio sensor control apparatus comprises a voltage control part configured to control a voltage Vo1 applied to a cell of an air-fuel ratio sensor in accordance with a sensor current flowing in the cell and a current detection part configured to detect the sensor current as a physical value, which indicates the air-fuel ratio. In the air-fuel ratio sensor control apparatus, a voltage varying time point, at which the voltage control part varies the voltage Vo1, and a current detecting time point, at which the current detection part detects the current, are shifted from each other. A time period Ta from the current detecting time point, which is immediately before the voltage varying time point, to the voltage varying time point and a time period Tb from the voltage varying time point to the current detecting time period, which is immediately after the voltage varying time point, are set to satisfy Ta<Tb.

Abstract: A control device of a nitrogen oxide sensor comprises a voltage control part configured to control voltage applied to the pump cell, and a temperature estimation part configured to estimate a temperature of the pump cell. The voltage control part is configured to make the voltage applied to the pump cell a voltage of a starting voltage of decomposition of water or more when the estimated temperature of the pump cell estimated by the temperature estimation part is within a predetermined temperature region of less than an activation temperature of the pump cell as control suppressing evaporation.

Abstract: The inventive subject matter is directed to point-of-care analytical devices that accurately determine the volume of test samples using image analysis to improve the accuracy of test results performed on the sample. Most preferably, the image analysis is based on rate changes in optical saturation that parallels sample saturation in a porous structure containing the sample.

Abstract: The described embodiments may provide a chemical detection circuit. The chemical detection circuit may comprise a column of chemically-sensitive pixels. Each chemically-sensitive pixel may comprise a chemically-sensitive transistor, and a row selection device. The chemical detection circuit may further comprise a column interface circuit coupled to the column of chemically-sensitive pixels and an analog-to-digital converter (ADC) coupled to the column interface circuit. Each column interface circuit and column-level ADC may be arrayed with other identical circuits and share critical resources such as biasing and voltage references, thereby saving area and power.

Abstract: A sensor control apparatus for a gas sensor which detects a particular gas component contained in a gas under measurement. In the case where humidity detection is performed using an electromotive-force-type gas sensor, a sensor control apparatus changes a target voltage of an electromotive force cell to a second target voltage for humidity detection and then to a third target voltage which is lower than a first target voltage which is a target voltage used for detecting the concentration of the particular gas component. In the case where humidity detection is performed using a limiting-current-type gas sensor, the sensor control apparatus changes the voltage applied to a pump cell to a second application voltage for humidity detection and then to a third application voltage which is lower than a first application voltage which is an application voltage used for detecting the concentration of the particular gas component.

Abstract: A method of verifying operation of a meter for reading electrochemical test devices, includes obtaining a reference output signal indicative of a response generated at an electrochemical test device when the electrochemical test device reacts with a reference test fluid; applying with the meter an algorithm to the reference output signal so as to obtain a reference test result, wherein the algorithm is for use in estimating an unknown concentration of an analyte in a sample of the reference test fluid; and determining whether the reference test result is valid so as to verify operation of the meter.

Abstract: According to at least one aspect of the present disclosure, a method includes applying an alternating current having a frequency at a selected voltage to a sensor, wherein the voltage is applied between a reference electrode and a working electrode of the sensor, varying the frequency of the alternating current between a lower frequency and an upper frequency, measuring an impedance of the sensor between the reference electrode and the working electrode as a function of the frequency of the alternating current, analyzing the measured impedance to determine a total impedance of the sensor and the real and imaginary components of the total impedance at each applied frequency of the alternating current, and characterizing the sensor based on the total impedance at the low frequency end of the sensor and on the real and imaginary components of the total impedances.

Abstract: Embodiments of the present technology include a system for analyzing a molecule. The system may include a device. The device includes a first conductive element, a second conductive element, and an insulating layer. The insulating layer may be tapered in a direction to reach a minimum thickness at a first end of the device. The insulating layer is disposed between the first conductive element and the second conductive element. The device may include a voltage source in electrical communication with the first conductive element and the second conductive element. The device may also include an electrical meter in electrical communication with the voltage source, the first conductive element, and the second conductive element.

Abstract: Embodiments of the inventive concept include a portable ion concentration apparatus including a controller, a storage section to store one or more data samples, an amplifier circuit, and a chemical field effect transistor (CHEMFET). The CHEMFET and the amplifier circuit can indicate a quantity of nitrate levels in a sample media or a reference media. The controller can process the indication of the quantity of nitrate levels, and generate the one or more data samples based at least on the indication of the quantity of nitrate levels. The portable ion concentration apparatus can include an in-field analysis apparatus, an in-field measurement apparatus, or an in-soil monitoring apparatus. A measurement logic section can determine an ion concentration based on a sensitivity slope M or a polynomial fit. Also disclosed is a method for measuring ion concentration with a standard deviation correction.

Abstract: Methods and systems are provided for reducing release of undesired emissions to atmosphere at a start event of an engine configured to propel a vehicle. In one example, a method comprises providing an alternative heat source and actively routing heat from the alternative heat source to a heated exhaust gas oxygen sensor for which a heating element configured to raise temperature of the sensor is known to be degraded. In this way, a desired air-fuel ratio may be attained during engine start events where the heating element for raising temperature of the sensor is degraded, which may thus reduce tail-pipe emissions which may otherwise be released in the absence of such mitigating action.

Abstract: A sensor control apparatus for a gas sensor which detects a particular gas component contained in a gas under measurement. In the case where humidity detection is performed using an electromotive-force-type gas sensor, a sensor control apparatus changes a target voltage of an electromotive force cell to a second target voltage for humidity detection and then to a third target voltage which is lower than a first target voltage which is a target voltage used for detecting the concentration of the particular gas component. In the case where humidity detection is performed using a limiting-current-type gas sensor, the sensor control apparatus changes the voltage applied to a pump cell to a second application voltage for humidity detection and then to a third application voltage which is lower than a first application voltage which is an application voltage used for detecting the concentration of the particular gas component.

Abstract: A smart dosimeter coupled to a legal dosimeter and used as if they were incorporated into one structure. A sensor, provided in the smart dosimeter, detects a worker is wearing the legal dosimeter. An instantaneous exposed dose value can be checked, in real time, to assist a worker with performing an operation or task. A motion detection unit detects a motion; a legal dosimeter detection unit checks whether the legal dosimeter is coupled to the smart dosimeter; a wearing check unit checks whether the worker is wearing the legal dosimeter based upon motion information; a G-M detection unit detects a real-time exposed dose of the worker; and a data communication unit transmits the exposed dose, detected by the G-M detection unit, to a management server and receives warning situation information from the management server.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for sensing. One example apparatus for sensing includes a sensor configured to supply a current indicative of a parameter and a bipolar transistor having a base coupled to the sensor to receive the current, the bipolar transistor being configured to generate an amplified current based on the current. The apparatus may also include a measurement circuit coupled to the bipolar transistor and configured receive the amplified current.

Abstract: A process and system for recovering gel-mass from a gel-mass-containing waste material. The process comprises retrieving the gel-mass-containing waste material from an encapsulation process; melting the retrieved waste material to provide an oil phase and a non-oil phase; retrieving the non-oil phase to produce a recovered gel-mass; and recycling the recovered gel-mass for combination with fresh encapsulating material to provide a combined encapsulating material for use in encapsulating a same lot of the same product which was being encapsulated in the step that produced the gel-mass-containing waste material from which the gel-mass was obtained. The system comprises a heated accumulator for receiving and melting the gel-mass-containing waste material to provide an oil phase and a non-oil phase; a pumping system; an optional mixer; and a control system.

Abstract: A system and method for aiding in the diagnosis of a respiratory dysfunction is described. More particularly, a system and method for aiding in the diagnosis of one or more pulmonary embolisms is described. The system and method described herein include a plurality of sensors, a thermal control system, and a controller coupled to the plurality of sensors and the thermal control system for aiding in the diagnosis of a respiratory dysfunction.

Abstract: The present invention relates to systems, methods, and devices for determining the concentration of an analyte in a sample. The use of linear, cyclic, or acyclic voltammetric scans and/or semi-integral, derivative, or semi-derivative data treatment may provide for increased accuracy when determining the concentration of an analyte in a sample. Hematocrit compensation in combination with the data treatments may reduce the hematocrit effect with regard to a glucose analysis in whole blood. In another aspect, fast scan rates may reduce the hematocrit effect.

Abstract: Method for the detection and quantification of the H2S which measures concentration of the H2S in the drilling mud including the steps of measurement of the initial concentrations of H2S in free form and of the hydrogen sulphide HS? and sulphide S2 ? ion species, dissolved in the sample of mud; acidification of the sample of mud, to generate gaseous H2S, making the hydrogen sulphide (HS?) and sulphide (S2?) ions dissolved in the mud and the H2S precipitated in solid form in the scavengers react; measuring concentration of the gaseous H2S formed following the first acidification; and relative system including at least: a mud sample collector; a unit measuring concentration of the hydrogen sulphide HS? and sulphide S2? ion species in the sample; a unit for measuring concentration of the free H2S; a unit to acidify the sample of mud; electronic controller and storage and processing of the measurements made.

Abstract: Provided is a flat plate-type oxygen sensor element. The flat plate-type oxygen sensor element according to an exemplary embodiment of the present invention includes: a first electrolyte layer having a sensing electrode exposed to a target gas; a second electrolyte layer on which a reference electrode is disposed; and a heating unit having a heating resistor surrounded by an insulating layer and disposed between the sensing electrode and the reference electrode, wherein the heating unit is disposed so that the heating resistor is located at a position ranging from 40 to 60% of a total height from an upper surface of the first electrolyte layer to a lower surface of the second electrolyte layer.

Abstract: An apparatus and method are provided for digitally controlling an oxygen sensor. The apparatus comprises a computer and digital circuitry coupled to the oxygen sensor to convey information between the oxygen sensor and the computer. The oxygen sensor includes a pump cell and at least one Nernst cell configured to indicate the difference in oxygen content in a test medium relative to a reference medium. A pump control circuit operates the pump cell according to signals received from the computer based on output signals from the Nernst cell. A reference voltage circuit enables the computer to determine impedances of the oxygen sensor as a function of sensor temperature and pressure. A Nernst read circuit transmits output signals from the oxygen sensor digitally to the computer. Digital signals received by the computer are compared with stored reference information so as to determine the oxygen content of the test medium.

Abstract: A semiconductor device, comprising a first field effect transistor (FET) connected in series to a second FET, and a third FET connected in series to the first FET and the second FET. The semiconductor device further includes bias circuitry coupled to the first FET and the second FET, and an output conductor coupled to a terminal of the second FET, wherein the output conductor obtains an output signal from the second FET that is independent of the first FET.

Abstract: A method for measuring the concentration of at least one gas from a gas sample by a sensor system (10) which has a measuring area (12) with at least one gas sensor (14), wherein the inlet of the measuring area (12) being closed by a gas-permeable structure (13) such that the volume of the measuring area (12) is initially heated up, the heating is then switched off and the change in resistance of the at least one gas sensor (14) is measured.

Abstract: The present invention relates to a system and method for detection of contraband such as concealed explosives, drugs, smuggled goods, etc., through the use of an acoustic frequency detector having a crystalline transducer module and mass comparator. The present invention can be employed in a non-destructive manner for the mobile and stationary inspection of object such as luggage, person, containers, etc., through a combination of computer-aided electron counting and mass analysis techniques combined with a crystalline and oil enhanced transducer that, upon return of a system-generated acoustic signal, are used to screen and confirm explosive threats and/or other contraband.

Abstract: A gas-detecting apparatus includes a measurement circuit including a gas sensor and a measurement instrument and a decision circuit. Detection cells, included in the gas sensor, each include a first electrode, a second electrode having a surface exposed from an insulation layer, and a metal oxide layer disposed between the first electrode and the second electrode. The resistance values of the detection cells are each allowed to decrease by a contact of gas containing hydrogen atoms with the second electrode. The measurement instrument monitors the resistance values of the detection cells. The decision circuit decides whether the gas is detected or not based on at least one change of the resistance values.

Abstract: Methods and systems are provided for sensing particulate matter by a particulate matter (PM) sensor positioned downstream of a diesel particulate filter in an exhaust system. In one example, a PM sensor assembly may include rows of flow guides separated from each other by a gap where each of the flow guide includes a positive and negative electrode formed on opposite side surfaces. By aligning projections in the gap between successive flow guides, exhaust PM may be circulated in the gap between the electrodes for a longer time, thus increasing the probability of capture across the electrodes, and thereby increasing the sensitivity of the assembly to detection of exhaust PM.

Abstract: Among other aspects, the present invention provides for the deposition of biological particles, such as cells, in a liquid, in a desired two-dimensional pattern on a planar surface of a substrate so as to permit rapid, simple, and sensitive detection of cells and/or sub-cellular components (e.g., proteins, biomarkers) disposed on the substrate. In various aspects, the systems and methods can enable reproducible high-throughput screening and/or allow for sensitive and specific detection of rare events in heterogeneous cell populations within a biological sample, with limited or no selective cell loss or sample enrichment.

Abstract: An acetic acid gas sensor based on an azobenzene compound includes an interdigital electrode and a coating material. The coating material is an azobenzene compound of formula I. The coating material is plated on the interdigital electrode through a vacuum coating process, and a thickness of the coating material is 100-200 nm.

Abstract: A method of operating an electrochemical gas sensor, which includes at least one working electrode including an electrocatalyst and having a ratio of total electrochemically accessible surface area to geometrical surface area of at least 2:1, includes alternatively biasing a potential of the at least one working electrode to a first potential at which the electrocatalyst is active to catalyze a redox reaction of a first target gas and to a second potential, different from the first potential, at which the electrocatalyst is substantially inactive to catalyze the redox reaction of the first target gas, a plurality of times, measuring a first output signal arising from the redox reaction of the first target gas at the first potential, and deconvoluting the first output signal while the at least one working electrode is biased at the first potential to separate a portion of the first output signal arising from non-faradaic current to determine a concentration of the first target gas.

Abstract: An O2 sensor includes a sensor element using a solid electrolyte layer and a pair of electrodes placed at a position to interpose the solid electrolyte layer, detects an exhaust gas from an internal combustion engine as an object of a detection, and outputs an electromotive force signal depending on an air-fuel ratio of the exhaust gas. The sensor element is connected with a constant current circuit supplying a constant current that is prescribed. A microcomputer calculates a resistance value (element resistance) of the sensor element, and performs a restriction on the constant current supplied by the constant current circuit on the basis of the element resistance.

Abstract: One embodiment provides an oscillator. The oscillator can include an organic electrochemical transistor, which comprises a channel and a dynamic gate. The channel can include one of: a conductive polymer, a conductive inorganic material, and a small-molecule material. An electrochemical potential of the dynamic gate can vary substantially periodically, thereby resulting in the organic electrochemical transistor having a drain current that varies substantially periodically.

Abstract: A controller for an internal combustion engine, the internal combustion engine including a fuel injection valve configured to supply fuel into a cylinder. The controller includes an electronic control unit configured to acquire an actual heat generation rate at time of combustion; and correct at least one of fuel injection pressure or amount of fuel injected when deviation amount between reference heat generation rate gradient and actual heat generation rate gradient is equal to or greater than predetermined value such that the deviation decreases. The reference heat generation rate gradient is a gradient of a predetermined reference heat generation rate at which a predetermined time elapses after a heat generation rate begins to rise. The actual heat generation rate gradient being a gradient of an actual heat generation rate acquired by the electronic control unit at which the predetermined time elapses after the heat generation rate begins to rise.

Abstract: A measurement cell (3) for measuring at least one constituent of a liquid sample, in particular blood, includes a reception space (9) for receiving the sample includes a measurement system (8) having at least one sensor electrode (10) exposed within the reception space; a first heat supply equipment (12) extending over a first area (91); a second heat supply equipment (14) extending over a second area (93), the first and second heat supply equipment being arranged to heat the sample within the reception space (9), wherein the second area (93) is larger than the first area (91).

Abstract: A movable measurement cell for measuring at least one constituent of a liquid sample, in particular blood, having a first portion comprising a measurement system having at least one sensitive area at a surface of the first portion: a second portion having at least a part of a reception space for the sample, the second portion is connected to the first portion such that the sample is in contact with the sensitive area when the sample is located within the reception space, and a sample supply system attached to an inlet to allow supply of a liquid sample into the reception space.

Abstract: The present invention provides a flow apparatus (10) for a vessel storing fluid under pressure having a flow control valve (12) having a housing (14) and an outlet aperture (16) and further including a valve seat (18) and a sealing member (20) for sealing against said seat (18) such as to obturate said outlet (16), said apparatus further including an actuator (22) connected to said sealing member (20) for moving it between an open position of the valve in which it unobturates the outlet aperture (16) and a closed position in which it obturates said outlet, characterized by an electrical switch (24) for controlling the supply of electrical current to one or more electrical components (25) and wherein said switch is operably connected to said sealing member (20) to allow for the passage of current when said valve (12) is in a first position and to restrict the flow of current when said valve (12) is in a second position.

Abstract: A metal terminal of a gas sensor includes a forward terminal member and a rear terminal member. The forward terminal member is made of a material superior in heat resistance to and greater in “0.2% yield strength” than a material of the rear terminal member. The forward terminal member has heat resistance suitable for a portion which comes into contact with a high-temperature detection element and is larger in an elastic deformation region than the rear terminal member, thereby providing good contact with the detection element and thus facilitating maintenance of electrical contact with the detection element. The rear terminal member is unlikely to have springback at a signal-wire connection portion to be connected to a lead wire, thereby facilitating maintenance of electrical connection with the lead wire.

Abstract: In order to provide a device for detection of a partial pressure of a measurement gas contained in a surrounding gas, comprising a measurement space with at least one inlet opening to admit surrounding gas into the measurement space and at least one outlet opening to discharge surrounding gas from the measurement space, a quantity that characterizes the partial pressure of the measurement gas in the measurement gas sensor sensitive to the measurement gas to measure a quantity that characterizes the partial pressure of the measurement gas in the measurement space, as well as readout device to read out the measurement gas sensor as well as a method for its operation, which permit metrological detection of the partial pressure of a measurement gas contained in a surrounding gas with improved chronological and spatial resolution, it is proposed that means to determine a response characteristic of device be provided.

Abstract: A gas sensor element (120) configured as a laminate of an oxygen pump cell (135) and an oxygen concentration detection cell (150) with a spacer (145) sandwiched therebetween. The spacer (145) has a gas detecting chamber (145c) formed therein and electrodes (138) and (152) of the cells (135) and (150), respectively, facing the chamber (145c). A leakage section (148) is faces the gas detecting chamber (145c) (measuring chamber).

Abstract: Methods and systems for producing high purity gaseous chlorine dioxide are provided. A solid chlorite reactant is contacted with an ozone-containing reactant gas, or a gas containing both ozone and a component that reacts with any hydroxide byproduct (such as carbon dioxide), to produce chlorine dioxide. The reaction can be monitored and controlled to ensure that excess chlorite reactant is provided and to prevent ozone from passing into the product gas.

Abstract: This control device for an internal combustion engine is equipped with: an air/fuel ratio sensor provided to the exhaust passage of an internal combustion engine; and an engine control device that controls the internal combustion engine on the basis of the sensor output current of the air/fuel ratio sensor. The air/fuel ratio sensor is equipped with: a gas chamber to be measured, into which exhaust gas flows; a reference cell for which the reference cell output current varies according to the air/fuel ratio of the exhaust gas inside the gas chamber to be measured; and a pump cell that, according to the pump current, pumps oxygen into or out of the exhaust gas in the gas chamber to be measured. The reference cell is configured so that the applied voltage, at which the reference cell output current reaches zero, varies according to the air/fuel ratio of the exhaust gas in the gas chamber to be measured.

Abstract: A method for checking the function of a sensor for detecting soot is provided, the sensor including at least two measuring electrodes situated on a substrate made of an electrically insulating material, and a heating element, the method including: carrying out a first current-voltage measurement at a first temperature to ascertain a first measured variable, carrying out a second current-voltage measurement at a second temperature to ascertain a second measured variable, and forming a difference between the first measured variable and the second measured variable.