A gas sensor includes an element body having an oxygen ion conductive solid electrolyte layer and internally provided with a measurement-object gas flow section that introduces a measurement-object gas and allows the gas to flow; a measurement-object gas-side electrode disposed in a portion of the element body, the portion being exposed to the measurement-object gas; and a reference electrode disposed inside of the element body. Let A [μA] be a limiting current when oxygen is pumped from the surroundings of the measurement-object gas-side electrode to the surroundings of the reference electrode with the measurement-object gas introduction section, and B [μA] be a limiting current when oxygen is pumped from the surroundings of the reference electrode to the surroundings of the measurement-object gas-side electrode with the reference gas introduction section, then a ratio A/B is greater than or equal to 0.005.

A gas sensor having a reliable measurement accuracy for specific gases even if a pump electrode is heated and a method for manufacturing the same are provided. The gas sensor is provided with a measurement target gas chamber, a reference gas chamber, a solid electrolyte, a pump electrode, a sensor electrode, a reference electrode and a heater. The pump electrode includes Pt, Au and an aggregate. After the gas sensor has been manufactured, in a state that the pump electrode has not been heated to an activation temperature of the solid electrolyte yet, in the pump electrode, a pore is 5.2 vol % or less, a surface roughness Ra is 0.5 μm to 9.1 μm, and a content ratio of the aggregate 31 is 4.9 vol % or more.

A broadband lambda probe includes a measurement hollow space. The broadband lambda probe further includes an oxygen pump cell having an outer pump electrode and an inner pump electrode to enable the transfer of oxygen from the measurement hollow space to an external environment of the broadband lambda probe. The broadband lambda probe further includes a Nernst concentration cell. The broadband lambda probe further includes at least one capacitive sensor device. The at least one capacitive sensor device has a capacitance configured to be varied with a change of a concentration of at least one substance. The concentration is present in the respective at least one capacitive sensor device. The at least one capacitive sensor device is positioned in the broadband lambda probe to at least one of directly adjoin the measurement hollow space and partially project into the measurement hollow space.

A broadband lambda probe includes a measurement hollow space. The broadband lambda probe further includes an oxygen pump cell having an outer pump electrode and an inner pump electrode to enable the transfer of oxygen from the measurement hollow space to an external environment of the broadband lambda probe. The broadband lambda probe further includes a Nernst concentration cell. The broadband lambda probe further includes at least one capacitive sensor device. The at least one capacitive sensor device has a capacitance configured to be varied with a change of a concentration of at least one substance. The concentration is present in the respective at least one capacitive sensor device. The at least one capacitive sensor device is positioned in the broadband lambda probe to at least one of directly adjoin the measurement hollow space and partially project into the measurement hollow space.

A gas sensor includes a sensor element and a control unit for controlling the sensor element. The sensor element includes a main pump cell, an auxiliary pump cell, a measurement pump cell, and a reference electrode, wherein, in the main pump cell, a repeatedly on-off controlled main pump current is applied so that an auxiliary pump current flowing through the auxiliary pump cell is at a predetermined target current value, and, in the auxiliary pump cell, the auxiliary pump current is applied so that an electromotive force between an inner auxiliary pump electrode and the reference electrode is at a predetermined target voltage value. The control unit includes: a control power supply for applying the repeatedly on-off controlled main pump current; and a setting part for setting the target voltage value based on an electric potential difference generated between the inner main pump electrode and the reference electrode.

A gas sensor includes a sensor element and a control unit for controlling the sensor element. The sensor element includes a main pump cell, an auxiliary pump cell, a measurement pump cell, and a reference electrode, wherein, in the main pump cell, a repeatedly on-off controlled main pump current is applied so that an auxiliary pump current flowing through the auxiliary pump cell is at a predetermined target current value, and, in the auxiliary pump cell, the auxiliary pump current is applied so that an electromotive force between an inner auxiliary pump electrode and the reference electrode is at a predetermined target voltage value. The control unit includes: a control power supply for applying the repeatedly on-off controlled main pump current; and a setting part for setting the target voltage value based on an electric potential difference generated between the inner main pump electrode and the reference electrode.

A gas sensor includes a sensor element and a controller. The sensor element includes an element body provided with a measurement-object gas flow section therein, a measurement electrode disposed in the measurement-object gas flow section, an outer pump electrode provided in the element body so that the outer pump electrode comes into contact with a measurement-object gas, a reference electrode, a reference-gas introduction section that causes a reference gas to flow to the reference electrode, and a reference-gas adjustment pump cell constituted by including the outer pump electrode and the reference electrode. The controller performs a moisture-absorption-state diagnosis process of diagnosing a moisture absorption state around the reference electrode based on a pump current flowing through the reference-gas adjustment pump cell when the reference-gas adjustment pump cell is controlled to pump out oxygen from a periphery of the reference electrode to a periphery of the outer pump electrode.

A gas sensor that detects a specific gas concentration in a measurement-object gas, the gas sensor includes: a sensor element having an element body provided with a measurement-object gas flow section therein, the measurement-object gas flow section introducing the measurement-object gas, a measurement electrode disposed in the measurement-object gas flow section, a measurement-object-gas side electrode provided on the element body, a reference electrode, a reference-gas introduction section that causes a reference gas to flow to the reference electrode, and a reference-gas adjustment pump cell constituted by including the measurement-object-gas side electrode and the reference electrode; and a controller that performs a moisture-concentration decrease process of controlling the reference-gas adjustment pump cell so that oxygen is pumped out from a periphery of the reference electrode to a periphery of the measurement-object-gas side electrode to decrease a moisture concentration around the reference electrode.

A gas sensor includes a sensor element and a control unit for controlling the sensor element. The sensor element includes: an adjustment pump cell for adjusting an oxygen concentration in a measurement-object gas to a desired concentration; a current measurement pump cell for detecting a target gas to be measured in the measurement-object gas as a current value, the current measurement pump cell including: an inner measurement electrode and an outer measurement electrode; a reference electrode; and an electromotive force detection sensor cell for detecting an electromotive force value between the inner measurement electrode and the reference electrode. The control unit includes a switching unit for switching whether a current flows through the current measurement pump cell or not.

A sensor element for detecting a physical property of a gas includes: a solid electrolyte film; a first end area and a second end area situated diametrically opposite in the longitudinal direction; a functional element in the first end area in the interior which is electrically conductively connected to a contact surface situated in the second end area on the outer surface, the electrically conductive connection having a strip conductor running essentially in the longitudinal direction in the interior of the sensor element; and a reference gas channel running essentially in the longitudinal direction of the sensor element communicating with a reference gas outside of the sensor element via a reference gas opening, the strip conductor and the reference gas channel being situated in such a way that at least a partial overlap occurs between them.