Abstract: An SCU as a control device for the gas sensor (first and second NOx sensors) includes an applied voltage switching unit for switching an applied voltage of a pump cell when a deterioration detecting function is performed, and a deterioration rate calculation unit for calculating a deterioration rate of a sensor cell based on a slope during a transient change in an output of the sensor cell according to a switching of the applied voltage by the applied voltage switching unit.

Abstract: A sensor element which has a pair of positive and negative detection electrodes disposed on a surface of an insulation body as a detecting portion and a cover body configured to cover an opening of a cylindrical housing. The cover body is provided with gas inlet and outlet holes via which the measuring gas is introduced and discharged. The pair of detection electrodes have a plurality of wire electrodes. The wire electrodes electrically connected to the positive electrode and the wire electrodes electrically connected to the negative electrode are alternately arranged in parallel. Any one of a first insulation layer which is a narrow electrode interval Dn and a second insulation layer which is a wide electrode interval Dw, arranged between adjacent wire electrodes, and the first insulation layer arranged in a center part of the detecting portion.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: A sensor element which has a pair of positive and negative detection electrodes disposed on a surface of an insulation body as a detecting portion and a cover body configured to cover an opening of a cylindrical housing. The cover body is provided with gas inlet and outlet holes via which the measuring gas is introduced and discharged. The pair of detection electrodes have a plurality of wire electrodes. The wire electrodes electrically connected to the positive electrode and the wire electrodes electrically connected to the negative electrode are alternately arranged in parallel. Any one of a first insulation layer which is a narrow electrode interval Dn and a second insulation layer which is a wide electrode interval Dw, arranged between adjacent wire electrodes, and the first insulation layer arranged in a center part of the detecting portion.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: An SCU as a control device for the gas sensor (first and second NOx sensors) includes an applied voltage switching unit for switching an applied voltage of a pump cell when a deterioration detecting function is performed, and a deterioration rate calculation unit for calculating a deterioration rate of a sensor cell based on a slope during a transient change in an output of the sensor cell according to a switching of the applied voltage by the applied voltage switching unit.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: A gas sensing element has at least a sensor cell consisting of a measured gas side electrode positioned in a measured gas chamber, a reference electrode being operative association with the measured gas side electrode, and a solid electrolytic substrate having surfaces on which the measured gas side electrode and the reference electrode are formed. The measured gas side electrode of the sensor cell contains at least one additive selected from the group consisting of Au, Ag, Cu, and Pb by an amount of 0.01 wt % to 2.0 wt % (external wt %) when an overall amount of the measured gas side electrode is 100 wt %.

Abstract: A gas concentration measuring system for use in air-fuel ratio control of motor vehicle engines is provided which is designed to determine the concentrations of oxygen as a function of an air-fuel ratio of a mixture supplied to the engine through a sensor element. The sensor element is activated by heat produced by an electric heater. The system works to sample the accumulated amount of energy inputted to the sensor element by the heat produced by the heater to determine whether the sensor element has been activated enough to produce an output representing an actual value of the air-fuel ratio correctly or not. Use of the accumulated amount of energy inputted to the sensor element will result in a decreased time required for such a determination as compared with the impedance of the sensor element.

Abstract: A gas sensor element is provided which is made of a laminate of an oxygen pump cell, a sensor cell, an oxygen monitor cell, and a heater. The laminate has affixed thereto terminals for establishing transmission of signals between themselves and an external device and also has conductive lines formed on portions of an outer surface of the laminate which connect between the respective cells and the terminals. This structure ensures a required degree of insulation resistance between the heater and the cells and also eliminates the disadvantages of a conventional structure that electric disconnections between the terminals and the cells or cracks occur in the laminate.

Abstract: Provided is a multilayer gas sensing element having a high measurement accuracy and less susceptible to a leakage current. The element comprises an oxygen pump cell for adjusting an oxygen concentration in a measured gas chamber, a sensor cell for detecting a specified gas concentration in the measured gas chamber, and a heater for heating the cells up to an activating temperature. The heater includes a heat generator for generating heat when energized, a heater terminal provided externally and a heater lead for making electrical connection therebetween. When the electrical resistance value of the heat generator is taken as RH and the electrical resistance value of the heater lead is taken as RL, these values are set to satisfy the relationship of 1.5≦RH/RL.

Abstract: A gas sensing element has a pump cell for pumping oxygen into or from a measuring-object gas chamber and a sensor cell for measuring the concentration of a specific gas contained in a measuring-object gas. The pump cell includes a measured gas side pump electrode exposed to the measuring-object gas stored in the measuring-object gas chamber.

Abstract: In a gas sensor element having a measurement gas chamber for introducing a measurement gas thereinto, a sensor cell, and an electrochemical cell, the sensor cell has an active electrode facing the measurement gas chamber, a first reference electrode forming a pair with the active electrode, and a solid-electrolyte plate having both the electrodes, and is so constructed that the concentration of a specific gas in the measurement gas chamber is detectable. The electrochemical cell has an inactive electrode facing the measurement gas chamber and being inactive to the specific gas, a second reference electrode forming a pair with the inactive electrode, and a solid-electrolyte plate having both the electrodes. The inactive electrode is formed of a metallic material containing at least one selected from Au, Ag, Cu and Pb and an additional metallic material Rh. This gas sensor element promises good measurement precision.

Abstract: A gas sensing element has at least a sensor cell consisting of a measured gas side electrode positioned in a measured gas chamber, a reference electrode being operative association with the measured gas side electrode, and a solid electrolytic substrate having surfaces on which the measured gas side electrode and the reference electrode are formed. The measured gas side electrode of the sensor cell contains at least one additive selected from the group consisting of Au, Ag, Cu, and Pb by an amount of 0.01 wt % to 2.0 wt % (external wt %) when an overall amount of the measured gas side electrode is 100 wt %.

Abstract: A gas sensor is provided which includes a sensor cell. The sensor cell is made up of a solid electrolyte member and a positive and a negative electrode installed on the solid electrolyte member. The sensor cell works to produce an electric current produced by a flow of oxygen ions from the negative to positive electrode which arises from dissociation of oxygen molecules on the negative electrode. An oxygen discharge chamber is provided on the positive electrode to discharge the oxygen molecules from outside the positive electrode, thereby eliminating an error of a sensor output caused by a stay of the oxygen molecules around the positive electrode.

Abstract: An oxygen sensor element includes a solid electrolyte having cavities on a surface thereof and an electrode formed on the surface of the solid electrolyte. In a method of producing the oxygen sensor element, a solution containing a noble metal compound for nucleus formation is first applied to an electrode forming portion of the solid electrolyte to form a coating film. Then, the coating film is heat-treated to form a nucleus forming portion where noble metal nuclei are deposited. Subsequently, metal plating is applied to the nucleus forming portion to form a plating film deeply entering the cavities. Thereafter, the plating film is burned to form the electrode deeply entering the cavities.

Abstract: An oxygen sensor element includes a solid electrolyte having cavities on a surface thereof and an electrode formed on the surface of the solid electrolyte. In a method of producing the oxygen sensor element, a solution containing a noble metal compound for nucleus formation is first applied to an electrode forming portion of the solid electrolyte to form a coating film. Then, the coating film is heat-treated to form a nucleus forming portion where noble metal nuclei are deposited. Subsequently, metal plating is applied to the nucleus forming portion to form a plating film deeply entering the cavities. Thereafter, the plating film is burned to form the electrode deeply entering the cavities.