Abstract: In a gas sensor, a gas sensor element includes a solid electrolyte body that has a bottomed tubular shape and a pair of reference and measurement electrodes that are respectively provided on the inner and outer surfaces of the solid electrolyte body. A cover is arranged to cover a distal end portion of the gas sensor element. The cover has at least one through-hole that is positioned on a distal side of the distal end portion of the gas sensor element in a longitudinal direction the gas sensor. The measurement electrode is positioned, on the outer surface of the solid electrolyte body, outside of an overlapping area that overlaps with the at least one through-hole of the cover in the longitudinal direction.

Abstract: A quickly activatable structure of a gas sensor element includes a measurement gas electrode, a reference gas electrode, a solid electrolyte layer to which the measurement and reference gas electrodes are affixed, and a heater. The heater has a heating element to heat the solid electrolyte layer. A reference gas chamber is defined between the solid electrolyte member and the heater and has a length made up of a first chamber and a second chamber. The first chamber is located in a heating area in which the heating element is disposed. The second chamber is located in a non-heating area and has at least a portion which is greater in volume per unit length of the reference gas chamber than the first chamber, thereby decreasing the dissipation of thermal energy to the non-heating area, which enhances the thermal transfer from the heating element to the solid electrolyte member.

Abstract: A gas sensor, a gas concentration detection system and a method of manufacturing the gas concentration detection system are disclosed. A gas sensor carries an individual information identifying section, which stores unique individual information related to the gas sensor. The individual information identifying section includes a two-dimensional information code readable with an image recognition device. The individual information identifying section includes a two-dimensional information code readable with an image recognition device. The gas concentration detecting system comprises, in addition to the gas sensor and the image recognition device, an engine control unit operative to correct a sensor output readout value, which is actually read out from the gas sensor, depending on information related to a sensor output value included in the information code.

Abstract: A method of manufacturing a gas sensor element which includes a solid electrolyte body, a target gas electrode a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas and the manufacturing method includes exposing the gas sensor element to a gas atmosphere containing at least one of a hydrocarbon gas, a CO2 gas, and a H2 gas and applying an ac voltage to said target gas electrode and the reference gas electrode. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries having a total length of 1000 &mgr;m or more in a surface area of 100 &mgr;m2.

Abstract: An oxygen sensor element is provided which may be used in an oxygen sensor designed to measure the concentration of oxygen contained in exhaust gasses of an automotive internal combustion engine. The gas sensor element includes a solid electrolyte body, a target gas electrode, a reference gas electrode, and a catalytic layer formed over the target gas electrode. The catalytic layer is made of heat resisting ceramic grains which hold thereon catalytic metal grains whose average grain size is 0.3 to 2.0 &mgr;m, a weight of catalytic metal grains per unit area of the catalytic layer, as defined by projecting the target gas electrode on a plane, is 10 to 200 &mgr;g/cm2. This facilitates the reaction of exhaust gasses such as H2, NOx, and HC with O2 over the target gas electrode, thus resulting in improved accuracy of a sensor output over a wide temperature range.

Abstract: A gas sensor element is provided which is used in a gas sensor such as an oxygen sensor. The gas sensor element includes a solid electrolyte body, a target gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a gas to be measured, and a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries. The total length of the grain boundaries in each of the target gas electrode and the reference gas electrode is 1000 &mgr;m or more in a surface area of 1000 &mgr;m2. This ensures a sufficient degree of diffusion of the gasses in the target and reference gas electrodes, thereby providing a rapid response rate to the gas sensor element.

Abstract: A gas sensor element is provided which is used in a gas sensor such as an oxygen sensor. The gas sensor element includes a solid electrolyte body, a target gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a gas to be measured, and a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries. The total length of the grain boundaries in each of the target gas electrode and the reference gas electrode is 1000 &mgr;m or more in a surface area of 1000 &mgr;m2. This ensures a sufficient degree of diffusion of the gasses in the target and reference gas electrodes, thereby providing a rapid response rate to the gas sensor element.

Abstract: An oxygen sensor element is provided which may be used in an oxygen sensor designed to measure the concentration of oxygen contained in exhaust gasses of an automotive internal combustion engine. The gas sensor element includes a solid electrolyte body, a target gas electrode, a reference gas electrode, and a catalytic layer formed over the target gas electrode. The catalytic layer is made of heat resisting ceramic grains which hold thereon catalytic metal grains whose average grain size is 0.3 to 2.0 &mgr;m, a weight of catalytic metal grains per unit area of the catalytic layer, as defined by projecting the target gas electrode on a plane, is 10 to 200 &mgr;g/cm2. This facilitates the reaction of exhaust gasses such as H2, NOx, and HC with O2 over the target gas electrode, thus resulting in improved accuracy of a sensor output over a wide temperature range.

Abstract: A solid electrolytic body has an inside space serving as a reference gas chamber. A sensing electrode and a reference electrode are formed on the surface of the solid electrolytic body. A heater is disposed in the reference gas chamber. A contact portion comprises a region where the heater is brought into contact with the inner surface of the solid electrolytic body and an opposing region on the outer surface of the solid electrolytic body. The sensing electrode includes at least part of the contact portion. A gas receiving surface region, exposed to the measuring gas, extends from an element tip to a position spaced by a distance L away from the element tip. At least part of the contact portion is located in a region extending from the element tip to a position spaced by a distance 0.4L away from the element tip. The sensing electrode is entirely located in a region extending from the element tip to a position spaced by a distance 0.8L away from the element tip.

Abstract: A gas sensor element is provided which is used in a gas sensor such as an oxygen sensor. The gas sensor element includes a solid electrolyte body, a target gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a gas to be measured, and a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries. The total length of the grain boundaries in each of the target gas electrode and the reference gas electrode is 1000 &mgr;m or more in a surface area of 1000 &mgr;m2. This ensures a sufficient degree of diffusion of the gasses in the target and reference gas electrodes, thereby providing a rapid response rate to the gas sensor element.