摘要:
A limiting current type oxygen analyzer designed for detecting oxygen concentration comprising a solid electrolyte element made from an oxygen ion conductive metal oxide and a pair of porous film electrodes provided on the inner and outer sides of said element respectively, at least one side electrodes being coated with a gas-diffusive resistive layer made from a porous insulating metal oxide, wherein the oxygen ions in the gas to which said element is exposed are caused to diffuse in the inside of said electrolyte element by applying a given voltage across said both electrodes and the limiting current corresponding to the concentration of said diffused oxygen ions is measured to determine the oxygen concentration in the gas to be analyzed, further characterized in that said gas-diffusive resistive layer is composed of a three-layer structure consisting of the first, second and third layers counted from the electrode side, said first layer having porosity of 11-15%, the second layer 6-8% and the third layer 15-20%.
摘要:
A device for sensing the oxygen concentration in an exhaust gas has a cup-like oxygen-ion permeable cylindrical member made of solid electrolyte consisting of oxygen-ion conducting metal oxide. The cylindrical member has an inner circumferential surface communicating with the atmosphere and an outer circumferential surface communicating with the exhaust gas for producing an electromotive force corresponding to a difference between the oxygen concentrations on the inner circumferential surface and on the outer circumferential surface and has a negative-resistance temperature characteristic. A pair of first electrodes serving as a lean sensor each comprise a thin film made of porous metal material and are provided on the inner circumferential surface and outer circumferential surface of the cylindrical member, respectively, in opposed relationship to each other. An oxygen-gas diffusion limiting layer covers the lean sensing electrode on the outer circumferential surface of the cylindrical member. A pair of second electrodes for sensing the oxygen concentration under high load drive mode and the temperature of the cylindrical member each comprises a thin film made of porous metal material and are provided, respectively, on those portions of the inner and outer circumferential surfaces of the cylindrical member which are different from the portions where the first electrodes are provided in opposed relationship to each other. A heater is disposed in the cylindrical member for heating the cylindrical member.
摘要:
An oxygen concentration sensor including a solid electrolyte member having two portions, one portion being exposed to a gas of interest and the other portion being exposed to the atmosphere, an inner cover formed with a first space communicating portion arranged to communicate with the other portion of the solid electrolyte member, and a water-proof cover enclosing the inner cover to define a ventilating passage between the inner cover and the water-proof cover and formed with a second space communicating portion maintaining the first space communicating portion of the inner cover in communication with the atmosphere through the ventilating passage. The second space communicating portion of the water-proof cover is axially spaced apart from the first space communicating portion of the inner cover by a predetermined distance. Also included is structure to prohibit the flow of water through said ventilating passage. The second space communicating portion is separated from this structure.
摘要:
A solid electrolyte for an oxygen concentration sensor is provided by mixing ZrO.sub.2 and about 6.5 to 7% by mol of a stabilizer such as Y.sub.2 O.sub.3, grinding the mixture to give a BET specific surface area of about 9 to 20 m.sup.2 /g, adding to the ground mixture a forming aid, forming the mixture into a predetermined configuration and firing the formed mixture at about 1420.degree. to 1480.degree. C. The electrolyte has a surface-average grain size of about 5 microns or less and a structure of a cubic phase and a monoclinic and/or tetragonal phase at the surface thereof and, furthermore, may contain about 5% or less of a monoclinic phase per the total of the cubic and monoclinic phases, in a finely ground state.
摘要翻译:通过将ZrO 2和约6.5〜7摩尔%的稳定剂如Y 2 O 3混合来提供氧浓度传感器的固体电解质,研磨该混合物,得到约9〜20m 2 / g的BET比表面积, 研磨混合物形成助剂,将混合物形成预定的构型,并在约1420℃至1480℃下焙烧所形成的混合物。电解质的表面平均粒度为约5微米或更小,立方相的结构和 在其表面具有单斜晶系和/或四方晶相,此外,在精细研磨状态下,每单位相和单斜相总共可含有约5%以下的单斜晶相。
摘要:
An oxygen concentration sensing apparatus in which a block of an oxygen-ion conductive solid electrolyte is interposed between a first electrode and a second electrode disposed opposite to each other. The first electrode is made of a catalytic metal and is exposed at a portion thereof on a surface of the solid electrolyte block, and an electrical insulating heat-resistive layer having a plurality of communication pores covers the exposed portion of the first electrode. The second electrode is porous and made of a catalytic metal. The solid electrolyte is wholly exposed to a stream of gases containing oxygen whose concentration is to be measured, and during measurement, a current source supplies continuously an electric current in a direction from the first electrode toward the second electrode. When the partial pressure of oxygen gas produced at the first electrode and existing in the vicinity thereof exceeds a predetermined value, the excess pressure portion of oxygen gas is discharged into the stream of gases through the communication pores of the heat-resistive layer thereby maintaining substantially constant the partial pressure of oxygen gas in the vicinity of the first electrode. An electromotive force representing the ratio between the partial pressure of oxygen around the first electrode and that in the stream of gases containing oxygen is measured to determine the concentration of oxygen contained in the gases.
摘要:
In an oxygen concentration sensing apparatus comprising a solid, oxygen ion conductive, electrolyte and intervening between two electrodes to generate across the two electrodes a potential difference due to a difference in oxygen concentrations at the boundaries between the two electrodes and the solid electrolyte, one of the two electrodes is made of a metal performing catalytic action, one end portion of the one electrode is embedded in the solid electrolyte to be fixed thereby, the other end portion of the one electrode projects outwardly of the solid electrolyte, a portion of the one electrode contacting with an outer surface of the solid electrolyte is hermetically sealed with a nonconductive layer of a heat-resistant material, and the other electrode is made of a porous metal performing catalytic action and is disposed on the outer surface of the solid electrolyte but preventing the other electrode from being in contact with the one electrode.Further, the oxygen concentration sensing apparatus may be provided with an electric circuit for making an electric current flow intermittently from the one electrode through the solid electrolyte to the other electrode thereby to maintain the oxygen concentration at the boundary between the one electrode and the solid electrolyte at a constant level.
摘要:
A process for the preparation of polyolefins, polymerizing olefins with use of a solid catalyst separated from a reaction mixture which is obtained by reducing a halogen-containing compound of vanadium with an organic aluminum compound in the presence of an ether and an organic aluminum compound.
摘要:
Provided is a filter medium including a porous polytetrafluoroethylene (PTFE) membrane and a gas-permeable supporting member that are integrated to ensure sufficient stiffness, having excellent gas permeability, and providing excellent bonding between respective layers included in the filter medium. The gas-permeable supporting member includes: a substrate having gas-permeability; and a fiber layer that is placed on the substrate so as to be in contact with the porous PTFE membrane. The gas-permeable supporting member has a structure in which fibers of the fiber layer enter into the substrate and are entangled with the substrate so that the fiber layer is bonded to the substrate. The fiber layer contains polyolefin-containing fibers that are bonded to the porous membrane.
摘要:
The swinging operation of a rotary striker turns micro switches and, which detect the position of a piston, ON/OFF. The striker includes a lower-limit switch cam and an upper-limit switch cam. The cams and engage with switch bosses and that move together with the piston. When the piston is positioned at a lower-limit stop position L, the cam becomes engaged with the boss to make the striker swing in the X-direction and pushes a switch button of the switch. When the piston is positioned at an upper-limit stop position U, the cam becomes engaged with the boss to make the striker swing in the Y-direction and pushes a switch button of the switch.
摘要:
A vented housing having high flame resistance, water resistance and insulation is provided. Furthermore, a ventilation member to be included in such a vented housing is provided. The ventilation member according to the present invention is a ventilation member to be fixed to a housing so as to cover an opening of the housing. The ventilation member includes: a support body in which a through hole is formed; and a gas permeable membrane that covers the through hole and allows a gas passing through the opening to permeate through the gas permeable membrane. The support body contains a polyphenylene ether resin or a polyphenylene oxide resin, and the gas permeable membrane is composed only of a porous polytetrafluoroethylene membrane.