Techniques for increasing the density and the number of cells on a nanopore sensor chip are disclosed. Two or more cells of the nanopore sensor chip share some analog components (e.g., an integration capacitor and/or a read-out transistor) through one or more digital relays. Under the control of various control signals during a sampling period of the sensor chip, the two or more cells are connected one at time to the shared analog components and are measured one at a time using the shared analog components. In this way, the average size of the cells on the sensor chip is reduced to increase the cell density without affecting the analog measurement performance of the cells.

An improved oxygen analyzer includes a controller configured to receive an oxygen sensor signal and provide an oxygen concentration output. A probe is configured to extend into a source of combustion process gas. An oxygen sensor is disposed within the probe and has a sensing electrode mounted to one side of a solid electrolyte and a reference electrode mounted to an opposite side of the solid electrolyte. The oxygen sensor has catalytic beads that are configured to be disposed between the process gas and the sensing electrode. Measurement circuitry is operably coupled to the oxygen sensor and the controller and is configured to provide the controller with the oxygen sensor signal based on an electrical response of the oxygen sensor. The controller is configured to detect a behavior of the oxygen sensor concentration output over time to provide at least one ancillary output.

A particular-gas concentration-measuring apparatus measures a particular gas concentration being the concentration of a particular gas in a measurement-object gas. The particular-gas concentration-measuring apparatus comprises a particular-gas concentration derivation unit. The particular-gas concentration derivation unit causes an electromotive-force acquisition unit to acquire an electromotive force and derives a correction value compensating for the difference between a correction-value derivation electromotive force that is the electromotive force and the reference electromotive force at a correction-value derivation time. The correction-value derivation time is a time during which a sensing electrode is exposed to a correction-value derivation gas, the correction-value derivation gas being the measurement-object gas where neither ammonia nor a combustible gas is assumed to be included. The particular-gas concentration derivation unit derives the particular gas concentration using a corrected electromotive force determined by correcting the electromotive force with the correction value.

An oxygen sensor is in a system including compensator circuitry connected to the oxygen sensor. The oxygen sensor includes a pump cell and the compensator circuitry includes a feedback control loop which includes a digital compensator which determines and outputs a compensation current to the pump cell or adjusts a pump cell voltage. A method of controlling the oxygen sensor includes, subsequent to a period of time when the feedback control loop is disrupted, pumping a balancing current into or out the pump cell for a balancing time interval, the balancing current and/or the balancing time interval is dependent on a current pumped into or out of the pump cell prior to the feedback control loop being disrupted.

A gas sensor includes a sensor element and a control unit thereof. The sensor element includes: a base part; a measurement-object gas flow cavity formed from one end part in a longitudinal direction of the base part; a pump cell including an intracavity electrode disposed in the measurement-object gas flow cavity; and a reference electrode disposed in a reference gas chamber formed inside the base part. The control unit includes: a driving control part; a storing part storing in advance, a standard correspondence relationship at a standard time at which a reference potential of the reference electrode is at a predetermined value; and a diagnosing part obtaining a diagnostic correspondence relationship, and comparing the obtained diagnostic correspondence relationship with the standard correspondence relationship to diagnose a deviation of a reference potential of the reference electrode at the diagnostic time from the predetermined value at the standard time.

An apparatus for measuring a concentration of a target gas includes: a gas sensor including a sensing layer having an electric resistance that changes by an oxidation reaction or a reduction reaction between gas molecules and the sensing layer; and a processor configured to, in response to the target gas being introduced along with air into the gas sensor, monitor a change of the electric resistance of the sensing layer and determine the concentration of the target gas by analyzing a shape of the change of the electric resistance.

A sensor control apparatus supplies a constant current to an oxygen concentration detection cell when it judges that oxygen concentration is greater than 15% (the concentration of oxygen contained in a measurement chamber is high). The sensor control apparatus detects a first difference voltage generated in the oxygen concentration detection cell as a result of the flow of the constant current to the oxygen concentration detection cell after a predetermined first detection time following the supply of the constant current. The sensor control apparatus detects a second difference voltage generated in the oxygen concentration detection cell as a result of the flow of the constant current to the oxygen concentration detection cell after a second detection time, which is previously set to be longer than the first detection time, following the supply of the constant current.

A sensor control apparatus includes a current control section, a first condition judgment section, a second condition judgment section, a deterioration detection energization section, and a deterioration voltage detection section. The current control section controls pump current such that electromotive force cell voltage becomes equal to a control target voltage. The first condition judgment section judges whether or not a first deterioration detection condition is satisfied. The second condition judgment section judges whether or not a second deterioration detection condition is satisfied when the first deterioration detection condition is satisfied. The deterioration detection energization section supplies deterioration detection current to the oxygen concentration detection cell when the second deterioration detection condition is satisfied. The deterioration voltage detection section detects a deterioration detection voltage generated in the oxygen concentration detection cell after a deterioration detection time following the supply of the deterioration detection current has been started.

A sensor element (100) including a measurement chamber (89); a pump cell (83) including a solid electrolyte body (69), an inner electrode (101), and an outer electrode (99); and a reference cell (85). At least one electrode contains a noble metal and a component of the solid electrolyte body. In a cross section, the at least one electrode has a noble metal region (205), a solid electrolyte body region (203), and a coexistence region (207) in which the noble metal and the component of the solid electrolyte body coexist. Further, in the cross section, an area ratio SR of the coexistence region is not less than 15.5% and is less than 30%.

In a gas sensor, a pump cell adjusts a concentration of oxygen in a gas chamber based of a pump cell supply voltage. A sensor cell detects a concentration of a specific gas in a detection target gas after the pump cell has adjusted the concentration of oxygen. In a sensor control unit, a voltage switching part adjusts the pump cell supply voltage to be supplied to the pump cell. A pump cell output control part adjusts a variation range of a pump cell output current of the pump cell before and after a voltage switching process of the pump cell supply voltage to be within a predetermined variation range. A deteriorated state detection part detects a deteriorated state ratio of the sensor cell based on variation of an output current of the sensor cell due to the voltage switching process performed by the voltage switching part.