摘要:
A ceramic insulating material, in particular for sensor elements for determining the concentration of gas components in gas mixtures, is based on an alkaline earth-containing ceramic. The insulating material contains a hexaaluminate of the alkaline earth metal and at least one mixed compound of the alkaline earth metal with an acid oxide, the molar ratio of hexaaluminate to the sum of mixed compounds in the insulating material being 1.3 to 4.0.
摘要:
An electrode system, particularly for installation in an exhaust line, has a holding body made of an insulating material, on which at least one operating electrode is positioned. The holding body has a heating device for facilitating easy cleaning in the installed position.
摘要:
A temperature sensor, in particular for a gas sensor, has at least one printed conductor, where a temperature-dependent change in a resistance of the printed conductor is detected and analyzed. The printed conductor has at least one section made of a solid electrolyte.
摘要:
A structural arrangement for NOx sensors including a first selectively oxygen ion-conductive layer and a second gas-permeable, nonconductive layer, the latter having a porous spinel structure or porous platinum. The oxygen ion-conductive layer made from a mixed-conductive ceramic can have an additional layer of a material which is catalytically inactive to NOx.
摘要:
A sensing element, in particular for an electrochemical sensor for determining gas concentrations, having at least one three-dimensional electrode arrangement, applied on a support plate and forming trenches of a depth for measuring changes in capacitance and/or conductivity in a gas-sensitive layer arranged to a height in the trenches, the height of the gas-sensitive layer being less than the depth of the trenches.
摘要:
The invention is directed to a method and an arrangement for diagnosing a catalytic converter arranged in the exhaust-gas system of an internal combustion engine. The catalytic converter is configured to have an oxygen storage capability and a nitrogen oxide storage capability. A first exhaust-gas probe is mounted rearward of the catalytic converter and a second exhaust-gas probe is mounted forward thereof. The oxygen concentration of the exhaust gas forward of the catalytic converter is alternately increased and decreased so that the signals of both exhaust-gas probes change. A first phase shift between the signals of both exhaust-gas probes is detected when the oxygen concentration increases and a second phase shift between the signals is detected when the oxygen concentration decreases. The difference of the phase shifts is determined and a fault signal is outputted and/or stored when this difference does not reach a pregiven threshold.
摘要:
A sensor for detecting combustible gases in a test gas. The core of this sensor is comprised of a sensitive layer based on a semiconducting metal oxide that is deposited on a ceramic substrate and for which the electrical resistance provides information on the concentration of combustible gases in a test gas. The sensitive layer (3) is comprised of a compound (12) of sintered-together grains (15) of the semiconducting metal oxide, the surface of which is coated with gold and/or a gold alloy. The semiconducting metal oxide in this case is stannic oxide (SnO.sub.2), indium oxide (In.sub.2 O.sub.3), titanium oxide (TiO.sub.2) or another n-semiconducting metal oxide or metal mix oxide. The gold alloy, for example, is composed of 66 mol % gold and 33 mol % palladium (Pd).
摘要:
The invention is directed to a method of determining the sensitivity of a hydrocarbon sensor for an internal combustion engine generating exhaust gas during the operation thereof. The hydrocarbon sensor includes a probe electrode subjected to the exhaust gas and a heater device for heating the probe electrode whereby a voltage (U) is generated in the sensor and is present at the probe electrode with the voltage (U) being a criterion for the concentration of hydrocarbon molecules in the exhaust gas. The voltage (U) present on the probe electrode is short circuited for a short time and the voltage (U) is measured as a function of time to obtain a voltage curve. A conclusion is then drawn as to the sensitivity of the hydrocarbon sensor from the voltage curve. The invention is also directed to an arrangement for carrying out the invention.
摘要:
A sensor for determining at least one of gas constituents and gas concentrations in a gas mixture, such as CO, NO.sub.x and HC, in exhaust gas from an internal combustion engine, includes a semiconductor gas sensor having a gas sensitive region in communication with the gas mixture; a pumping cell including a solid electrolyte carrier and pumping electrodes disposed on the solid electrolyte carrier, the pumping cell being positioned in communication with the semiconductor gas sensor for effecting oxygen transfer to the semiconductor gas sensor on the side thereof opposite the gas mixture by pumping oxygen thereto to provide an O.sub.2 mole current density in the gas sensitive region, and the pumping cell having a pumping current; a cover layer which is gas tight and which has a restricted opening defined therein provided on the pumping cell on the side thereof which communicates with the semiconductor gas sensor so that the oxygen is pumped through the restricted opening to the semiconductor gas sensor, whereby the O.sub.2 mole current density in the gas sensitive region can be increased within the restricted opening while the pumping current remains constant, the gas sensitive region of the semiconductor gas sensor being disposed in the restricted opening so that an oxygen excess is established at the gas sensitive region due to the O.sub.2 mole current density.