摘要:
A gas sensor and a method for its manufacture are described. The gas sensor has a solid electrolyte having at least one measuring electrode and one porous protective coating. The measuring electrode has an electrically conductive base layer and a further layer, the further layer god being deposited in the pores of the porous protective coating adjacent to the base layer via galvanic deposition. In order to deposit the further layer via galvanic deposition, the basic body, which has been fused with the base layer and the protective coating via vitrification, is immersed in a galvanizing bath, the base layer being connected as the cathode.
摘要:
An electrochemical sensor determining a gas concentration of the measuring gas. The sensor has an electrochemical element including a first solid electrolyte body having an electrochemical pump cell and a first (external pump) and a second (internal pump) electrode and having a gas chamber which is connected to the measuring gas chamber via a gas supply opening and in which the second electrode is arranged. The electrochemical element also includes a second solid electrolyte body having an electrochemical sensor cell (e.g., a Nernst cell) and a third and fourth electrode, each electrode having a lead for the electrical contacting. The leads of the first and second electrodes are decoupled capacitively from the lead of at least the fourth electrode by a device.
摘要:
A sensor arrangement for determining at least one of gas components and gas concentrations of gas mixtures including CO, NO.sub.x and HC in exhaust gases of internal combustion engines, includes a measuring element which has a sensitive region; and a pump cell that includes a solid electrolyte and inner and outer pump electrodes which are opposingly disposed at least on the solid electrolyte and which effect an oxygen transfer to the measuring element, wherein the pump cell and the measuring element are spatially separated from one another, are located in different temperature zones during operation of the sensor arrangement, and are connected to one another by a diffusion segment through which oxygen can diffuse from the pump cell to the measuring element.
摘要:
The invention is directed to a method of operating an exhaust-gas probe having a pumped reference atmosphere in a relatively closed volume. In this method, the oxygen ion current, which carries the pump current Ip to the reference atmosphere, is temporarily increased under specific conditions. In this way, an adulteration of the reference atmosphere can be more rapidly eliminated. This adulteration can occur because of fuel particles which diffuse in.
摘要:
A method is presented for determining the fuel/air ratio in the individual cylinders (single cylinder lambda) of an internal combustion engine having a plurality of cylinders, whose exhaust gases mix together in a common exhaust gas pipe system, from the signal of an exhaust gas probe, whose mounting location lies in the common exhaust gas pipe system, with the aid of an invertible model for the intermixing of the exhaust gases at the mounting location of the exhaust gas probe. The method is distinguished in that, in the determination of the single cylinder lambda from the signal of the one exhaust gas probe evaluated with the aid of the inverted model, the rotational angle position of the exhaust gas probe at its mounting position is taken into consideration.
摘要:
A probe is described for determining an oxygen concentration in a gas mixture, in particular in the exhaust gas of internal combustion engines, having a Nernst measuring cell, which has a first electrode (Nernst electrode) which is exposed to the gas mixture to be measured via a diffusion barrier, a second electrode (reference electrode) which is exposed to a reference gas, and a solid electrolyte body arranged between the first and the second electrode, and having a pump cell, which has a first electrode (inner pump electrode) which is exposed to the gas mixture via the diffusion barrier, a second electrode (outer pump electrode) which is exposed to the gas mixture, and a solid electrolyte body arranged between the first and the second electrode. The Nernst electrode and the inner pump electrode are connected at least in some sections via a joint supply conductor to a circuit arrangement for controlling and evaluating the probe. A joint supply conductor resistor of the Nernst electrode and of the inner pump electrode is formed by a loaded voltage divider whose individual resistors are arranged so that the negative feedback of a Nernst voltage circuit and of a pump voltage circuit is optimized, in particular maximized.
摘要:
An electrochemical sensor for ascertaining a gas concentration of a measuring gas includes an electrochemical element, including a first solid electrolyte body having an electrochemical pump cell and a first and a second electrode, and having a gas compartment which is connected via a gas access opening to the measuring-gas compartment, and in which one of the two electrodes is arranged. The electrochemical element further includes a second solid electrolyte body having an electrochemical sensor cell (Nernst cell) and a third and a fourth electrode. The surface of the first solid electrolyte body faces the measuring-gas compartment, and the gas access opening is covered by a porous protective layer. The electrochemical sensor includes a layer that exhibits a higher density or a lower porosity compared to the protective layer and that is allocated to the porous protective layer.
摘要:
A connection between electrically conducting layers (11, 14, 21) extending in at least two layer levels is proposed, between which at least one ceramic foil (10) is arranged. The ceramic foil has a connection (13) from the one layer level to the other layer level. A contact point (23) is provided in at least one layer level which is located outside of the connection (13) and which is formed by at least one pressure contact (10, 20) formed on an electrically conducting layer (14, 21) during lamination.
摘要:
A sensor arrangement for determining at least one of gas constituents and gas concentrations of a gas mixture including oxidizable gas constituents includes a diffusion duct having a gas mixture gas orifice in communication with the gas mixture and having a reference gas orifice in communication with a reference gas; and a measuring element having a sensitive zone which is positioned in the diffusion duct, the sensitive zone being exposed to the gas mixture via the gas mixture gas orifice and being exposed to the reference gas via the reference gas orifice, wherein the reference gas and the gas mixture have respective oxygen partial pressures, and wherein the oxygen partial pressure of the reference gas is higher than the oxygen partial pressure of the gas mixture so that oxygen is present in the sensitive zone of the measuring element in amounts sufficient to oxidize the oxidizable gas constituents to be measured. In this sensor arrangement, oxygen concentration changes have a negligibly small effect on the sensitive zone and cross-sensitivity of the measuring element with respect to oxygen is largely eliminated.
摘要:
A sensor for determining gas components and/or gas concentrations in gas mixtures, in particular in exhaust gases of internal combustion engines. The sensor has an oxygen pump cell and a measuring element having a sensitive region. Provided between the pump cell and the gas mixture is a diffusion path in which there are formed an oxygen gradient XO.sub.2 and a gradient X.sub.CO of the gas component to be determined, which extend respectively in opposite directions. The measuring element is positioned relative to the pump cell and the diffusion path in such a way that an excess of oxygen is present on the sensitive region of the measuring element.