A gas sensor includes a sensor element, a detection device, a reference gas regulating device. The sensor element includes an element body having disposed therein a measurement-object gas flow section, a measurement-object-gas-side electrode disposed in or out of the element body, a reference electrode disposed within the element body, and a reference gas introducing section that allows a reference gas to be introduced thereinto and to flow therethrough to the reference electrode. The reference gas regulating device allows an oxygen pump-in current to flow between the reference electrode and the measurement-object-gas-side electrode to pump oxygen into around the reference electrode from around the measurement-object-gas-side electrode. A ratio R1/R2 of a reaction resistance R1 of the reference electrode to a diffusion resistance R2 of the reference gas introducing section is greater than or equal to 0.1 and less than or equal to 2.0.

A handheld portable oxygen monitor for monitoring oxygen includes one or more of (1) a replaceable dust filter element removably disposed in a gas inlet pathway extending from an gas inlet port to an oxygen sensor, (2) an oxygen sensor module including the oxygen sensor and a circuit board on which the oxygen sensor is mounted, the oxygen sensor module being removably mounted to a circuit board holder, (3) configurable gas pathway components within the oxygen monitor housing, and (4) a controller operable to enable a remote device to (a) control one or more operations of the oxygen monitor, (b) receive real-time oxygen monitoring data from the oxygen monitor for display on the remote device, (c) upload logging event data from the oxygen monitor storage, (d) obtain system information from the oxygen monitor storage, and (e) perform firmware updates on the oxygen monitor to modify its programming.

A handheld portable oxygen monitor for monitoring oxygen includes one or more of (1) a replaceable dust filter element removably disposed in a gas inlet pathway extending from an gas inlet port to an oxygen sensor, (2) an oxygen sensor module including the oxygen sensor and a circuit board on which the oxygen sensor is mounted, the oxygen sensor module being removably mounted to a circuit board holder, (3) configurable gas pathway components within the oxygen monitor housing, and (4) a controller operable to enable a remote device to (a) control one or more operations of the oxygen monitor, (b) receive real-time oxygen monitoring data from the oxygen monitor for display on the remote device, (c) upload logging event data from the oxygen monitor storage, (d) obtain system information from the oxygen monitor storage, and (e) perform firmware updates on the oxygen monitor to modify its programming.

A solid electrolyte includes partially stabilized zirconia in which a stabilizer forms a solid solution in zirconia. The partially stabilized zirconia includes at least monoclinic phase particles and cubic phase particles as crystal particles that configure the partially stabilized zirconia, and an abundance ratio of the monoclinic phase particle is 5 to 25% by volume. The partially stabilized zirconia includes stabilizer low-concentration phase particles of which concentration of the stabilizer at a particle center is equal to or less than 1 mol %, as the crystal particles. The stabilizer low-concentration phase particles have a particle-size distribution of number frequency thereof having a peak at which an average particle size is 0.6 to 1.0 μm, and a particle size at 10% of a cumulative number is 0.5 μm or greater, and of the overall low-concentration phase particles, 50% by volume or greater belong to the peak.

A solid electrolyte includes partially stabilized zirconia in which a stabilizer forms a solid solution in zirconia. The partially stabilized zirconia includes at least monoclinic phase particles and cubic phase particles as crystal particles that configure the partially stabilized zirconia, and an abundance ratio of the monoclinic phase particle is 5 to 25% by volume. The partially stabilized zirconia includes stabilizer low-concentration phase particles of which concentration of the stabilizer at a particle center is equal to or less than 1 mol %, as the crystal particles. The stabilizer low-concentration phase particles have a particle-size distribution of number frequency thereof having a peak at which an average particle size is 0.6 to 1.0 μm, and a particle size at 10% of a cumulative number is 0.5 μm or greater, and of the overall low-concentration phase particles, 50% by volume or greater belong to the peak.

A process oxygen analyzer includes a process probe extendible into a flow of process combustion exhaust, the process probe having an oxygen sensor measurement cell. Measurement circuitry is coupled to the oxygen sensor measurement cell and configured to obtain a non-corrected indication of oxygen concentration relative to a combustion process based on an electrical characteristic of the oxygen sensor measurement cell. A controller is operably coupled to the measurement circuitry and is configured to obtain an indication of process pressure and selectively provide a corrected oxygen concentration output based on non-corrected indication of oxygen concentration and the indication of process pressure. A method of providing a process oxygen concentration using a process oxygen analyzer coupled to an industrial combustion process is also disclosed.

A process oxygen analyzer includes a process probe extendible into a flow of process combustion exhaust, the process probe having an oxygen sensor measurement cell. Measurement circuitry is coupled to the oxygen sensor measurement cell and configured to obtain a non-corrected indication of oxygen concentration relative to a combustion process based on an electrical characteristic of the oxygen sensor measurement cell. A controller is operably coupled to the measurement circuitry and is configured to obtain an indication of process pressure and selectively provide a corrected oxygen concentration output based on non-corrected indication of oxygen concentration and the indication of process pressure. A method of providing a process oxygen concentration using a process oxygen analyzer coupled to an industrial combustion process is also disclosed.

A gas sensor includes a sensor element, and the sensor element includes a bottomed tubular solid electrolyte, a detection electrode provided on an outer surface of the solid electrolyte, a reference electrode provided on an inner surface of the solid electrolyte. The detection electrode of the sensor element includes a detection electrode section provided at a position on a tip side of an axial direction, an attachment electrode section provided at a position on a base end side of the axial direction, and a lead electrode section provided at a position where the detection electrode section is connected to the attachment electrode section. An insulating layer is provided between a tube of the solid electrolyte and each of the attachment electrode section and the lead electrode section.

A gas sensor includes a sensor element, and the sensor element includes a bottomed tubular solid electrolyte, a detection electrode provided on an outer surface of the solid electrolyte, a reference electrode provided on an inner surface of the solid electrolyte. The detection electrode of the sensor element includes a detection electrode section provided at a position on a tip side of an axial direction, an attachment electrode section provided at a position on a base end side of the axial direction, and a lead electrode section provided at a position where the detection electrode section is connected to the attachment electrode section. An insulating layer is provided between a tube of the solid electrolyte and each of the attachment electrode section and the lead electrode section.

A gas sensor (200) including a sensor element (10) having electrode pads (11a-12b); a separator (166); and a plurality of metal terminals (21a, 21b, 22a, 22b) each having a body portion (21a1) and a front end portion (21a2), and being insulated from each other by the separator. The separator has an element storage portion (168) penetrating in the axial-line direction or recessed toward a rear side from a front facing surface of the separator, the element storage portion has a first storage space (168a) at a front side thereof and a second storage space (168b) at a rear side thereof, the second storage space has a rotation restriction wall (168w) configured such that a relative rotation allowable angle 2θ between the sensor element and the separator is smaller than in the first storage space, and the rear end side of the sensor element is stored in the second storage space.