Abstract: An electrochemical device has an electrochemical cell provided with an electrolyte having proton conductivity, an anode provided on one side of the electrolyte, and a cathode provided on the other side of the electrolyte. The electrochemical device is configured so that a solution containing water, an artificial synthetic resin, and an acid is supplied to the anode. The electrochemical device is configured so that an oxygen-containing gas is supplied to the cathode and connecting a load between the anode and the cathode. The electrochemical device is configured so that the inert gas is supplied to the cathode and connecting the voltage application unit between the anode and the cathode.

Abstract: A gas sensor, an oxygen concentration measuring unit, and a computation unit are included. The gas sensor measures a concentration CNOX of specific gas contained in measured gas. The oxygen concentration measuring unit measures a concentration CO2 of oxygen in the measured gas outside the gas sensor. The gas sensor has a measured gas chamber, a reference gas chamber, a diffusion resistance unit, a pump cell, and a sensor cell. The computation unit computes a concentration CNOX of the specific gas by using the concentration CO2 of oxygen measured by using the oxygen concentration measurement unit and the sensor current.

Abstract: An electrochemical device has an electrochemical cell provided with an electrolyte having proton conductivity, an anode provided on one side of the electrolyte, and a cathode provided on the other side of the electrolyte. The electrochemical device is configured so that a solution containing water, an artificial synthetic resin, and an acid is supplied to the anode. The electrochemical device is configured so that an oxygen-containing gas is supplied to the cathode and connecting a load between the anode and the cathode. The electrochemical device is configured so that the inert gas is supplied to the cathode and connecting the voltage application unit between the anode and the cathode.

Abstract: There is described a gas sensor element 1 including a solid electrolyte body 11, insulators 15, 141, 142, 197, 161, 162, 163, 164, 165, and a pair of electrodes 121, 131 formed such that the solid electrolyte body 11 is held therebetween. The gas sensor element 1 satisfies the following requirement (a) and/or the requirement (b). (a) The solid electrolyte body 11 is made of ion-conductive composite material in which nanoparticles with specific particle diameters are dispersed in ion-conductive ceramics. (b) The insulators 15, 141, 197, 161, 162, 163, 164, 165 are made of insulative composite material in which nanoparticles with specific particle diameters are dispersed in insulative ceramics. Further, there is described a manufacturing method of a gas sensor element in which the particle diameter and dispersion quantity of the nanoparticles dispersed in the solid electrolyte body 11 and/or insulative ceramics 11 are controlled.

Abstract: An air-fuel ratio sensor includes a sensor element inserted through a cylindrical housing for detecting an air-fuel ratio in an atmosphere of unburnt gas, and a measured gas side cover disposed on an end of the cylindrical housing so as to cover the sensor element and defining an inside chamber for storing therein a gas to be measured. The cover has a nested structure composed of a plurality of cup-shaped cover members disposed one inside another, each cover member having a gas inlet hole formed in a side wall thereof and a bottom hole formed in a bottom wall thereof. The gas inlet hole of an innermost one of the plural cover members that directly faces the sensor element is offset from an air-fuel ratio detecting portion of the sensor element toward the housing in an axial direction of the sensor.

Abstract: A gas sensing element includes a solid electrolyte body having oxygen ionic conductivity, a measured gas side electrode provided on one surface of the solid electrolyte body, and a reference gas side electrode provided on the other surface of the solid electrolyte body. The measured gas side electrode is positioned in a chamber space. The gas sensing element has an introducing hole connecting the chamber space to a measured gas atmosphere outside of the gas sensing element. The introducing hole is filled with a porous member having an average pore diameter of 2 to 30 ?m.

Abstract: An air-fuel ratio sensor includes a sensor element inserted through a cylindrical housing for detecting an air-fuel ratio in an atmosphere of unburnt gas, and a measured gas side cover disposed on an end of the cylindrical housing so as to cover the sensor element and defining an inside chamber for storing therein a gas to be measured. The cover has a nested structure composed of a plurality of cup-shaped cover members disposed one inside another, each cover member having a gas inlet hole formed in a side wall thereof and a bottom hole formed in a bottom wall thereof. The gas inlet hole of an innermost one of the plural cover members that directly faces the sensor element is offset from an air-fuel ratio detecting portion of the sensor element toward the housing in an axial direction of the sensor.

Abstract: An objective gas is successively introduced into first and second chambers which are connected via a narrow passage. A first monitor cell, provided on a surface of the first chamber, generates an electromotive force representing an oxygen concentration in the first chamber. A second monitor cell, provided on a surface of the second chamber, generates an electromotive force representing an oxygen concentration in the second chamber. A voltage applied to a pump cell is controlled based on the electromotive forces obtained from the first and second monitor cells.

Abstract: A gas sensor element consists of an oxygen pump cell, an oxygen monitor cell, and a sensor cell. The oxygen monitor cell measures the concentration of the oxygen molecules within the gas cavity which is fed back to the oxygen pump cell for keeping the concentration of oxygen molecules within the gas cavity constant. The sensor cell ionizes a specified oxygen containing gas and produce a signal indicative of the concentration of the specified oxygen containing gas within the gas cavity. The oxygen monitor cell and the sensor cell are disposed at substantially the same location in a direction of flow of the gasses, thereby minimizing a difference in concentration of oxygen molecules around the oxygen monitor cell and the sensor cell for eliminating an error of the signal outputted from the sensor cell arising from a variation in concentration of oxygen molecules within the gas cavity.

Abstract: An objective gas is successively introduced into first and second chambers which are connected via a narrow passage. A first monitor cell, provided on a surface of the first chamber, generates an electromotive force representing an oxygen concentration in the first chamber. A second monitor cell, provided on a surface of the second chamber, generates an electromotive force representing an oxygen concentration in the second chamber. A voltage applied to a pump cell is controlled based on the electromotive forces obtained from the first and second monitor cells.

Abstract: A gas sensor has a housing, a gas sensing element held by the housing and having a gas contact portion and an element cover for covering the gas contact portion. The element cover has a double pipe structure formed by layering an outer pipe and an inner pipe. The outer pipe has an outer bottom portion having an outer bottom hole and an outer side portion having plural outer side holes. The inner pipe has an inner bottom portion having an inner bottom hole and an inner side portion having plural inner side holes disposed not to overlap the outer side holes. A spacing D of 0.2-1.0 mm is formed between the outer bottom portion and the inner bottom portion. As a result, flow resistance in the spacing D is relatively high, and the sample gas sufficiently and more smoothly flows toward the gas sensing element. Therefore, the element cover prevents condensed water from entering the inside of the gas sensor and improves response of the gas sensor.

Abstract: PZT piezoelectric ceramics for forming a piezoelectric transformer includes a main composition consisting of Pb [Zr.sub.A Ti.sub.B (Zn.sub.1/3 Nb.sub.2/3).sub.c (Mn.sub.1/2 W.sub.1/2).sub.D ]O.sub.3. When A/B is in a range of 0.92-1.13, C is 0 or larger, D is in a range of 0.02-0.08 and total of A, B, C and D is 1, the piezoelectric transformer is fired at 1,100.degree. C. or lower, while having relatively high voltage rising ratio and efficiency. Therefore, a relatively low-priced Ag--Pd electrode having heat resistance of approximately 1,100.degree. C. can be used as an inside electrode of a laminated-type transformer. Thus, production cost of the piezoelectric transformer is reduced while the transformer has relatively high voltage rising ratio and efficiency.