A control device of a nitrogen oxide sensor comprises a voltage control part configured to control voltage applied to the pump cell, and a temperature estimation part configured to estimate a temperature of the pump cell. The voltage control part is configured to make the voltage applied to the pump cell a voltage of a starting voltage of decomposition of water or more when the estimated temperature of the pump cell estimated by the temperature estimation part is within a predetermined temperature region of less than an activation temperature of the pump cell as control suppressing evaporation.

Described herein is an apparatus and methods for characterizing a fluid composition including exposing electrolyte to one fluid mixture, collecting a signal from an electrode in contact with the electrolyte, and simultaneously exposing the electrolyte to a second fluid, collecting a signal from a second electrode in contact with the electrolyte exposed to the second fluid, and comparing the signal difference between the electrodes with the Nerst equation wherein the temperature of the electrolyte is above 488° C. Carbon dioxide, nitrogen, and/or oxygen may be present in the fluid and/or the second fluid.

A membrane electrode assembly of an electrochemical device includes a proton conductive solid electrolyte membrane and an electrode including Ni and an electrolyte material which contains as a primary component, at least one of a first compound having a composition represented by BaZr.sub.1-x1M.sup.1.sub.x1O.sub.3 (M.sup.1 represents at least one element selected from trivalent elements each having an ion radius of more than 0.720 A° to less than 0.880 A°, and 0<x.sub.1<1 holds) and a second compound having a composition represented by BaZr.sub.1-x2Tm.sub.x2O.sub.3 (0<x.sub.2<0.3 holds).

A nitrogen oxide based gas sensor includes: a substrate provided with a beam structure having a MEMS structure; a heater disposed on the substrate; a lower electrode disposed on the heater, a solid electrolyte layer disposed on the lower electrode; an upper electrode disposed on a surface of the solid electrolyte layer facing the lower electrode and configured to introduce a measurement target gas; a cavity portion formed in the substrate; and a gas flow path disposed so as to connect the cavity portion and the lower electrode, wherein the gas sensor is configured to detect a concentration of nitrogen oxide in the measurement target gas.

An inspection apparatus capable of performing responsivity inspection on a plurality of gas sensors at equivalent accuracies is provided. The inspection apparatus includes a plurality of inspected sensor disposing parts that are provided halfway through one gas flow path at equal intervals in an extending direction of the flow path and in each of which a gas sensor to be inspected is disposed, and a plurality of straightening plates provided upstream of each of the inspected sensor disposing parts on the gas flow path and separated at a constant distance from the inspected sensor disposing parts. The straightening plates each include a rectangular opening orthogonal to the gas flow path and open to the gas flow path. When the gas flow path extends in one direction in a horizontal plane, the opening has a longitudinal direction along a direction orthogonal to the one direction in the horizontal plane.

A sensor element 101 includes an element main body 101a that includes oxygen ion-conductive solid electrolyte layers (1 to 6), and a porous protective layer 90 that covers at least part of the element main body 101a. The porous protective layer 90 includes a porous inner protective layer 92 and a porous outer protective layer 91 disposed on the outer side of the inner protective layer 92 and having a smaller average pore diameter than the inner protective layer 92.

A gas sensor includes: an insulating substrate; a gas sensing portion immobilized on the substrate and comprising MoS.sub.2 flakes containing metal porphyrin; and a Pair of electrodes formed at both ends of the MoS.sub.2 flakes of the gas sensing portion so as to be spaced apart from each other. When MoS.sub.2 flakes are functionalized using cobalt tetraphenylporphyrin as metal porphyrin, the sensitivities thereof to benzene and toluene are significantly increased.

A sensor for detecting volatile organic compounds (VOCs) includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode.

A sulfur oxide detection system includes an element part which includes a sensor cell and a diffusion regulating layer. The sensor cell includes a solid electrolyte layer, a first electrode arranged, and a second electrode. The sulfur oxide detection system also includes a voltage application circuit configured to apply a voltage to the sensor cell so that a potential of the second electrode becomes higher than a potential of the first electrode, and a current detection circuit configured to detect a current flowing between the first electrode and the second electrode. The sulfur oxide detection system further includes a controller coupled with the voltage application circuit and the current detection circuit, and configured to estimate a sulfur oxide concentration in a gas to which the first electrode is exposed by way of the diffusion layer.

The object of the invention is to detect a concentration of a SOx included in an exhaust gas of an internal combustion engine easily and accurately by a limiting current type sensor. The invention relates to a SOx concentration detection device of the engine having a limiting current type sensor. The device of the invention comprises a detecting part for detecting the concentration of the SOx included in the exhaust gas by using an output current of the sensor while lowering a voltage applied to the sensor from a predetermined voltage.