Robert Boschgmbh

Bosch-siemens Hausgeraete Gmbh

Detlef Baresel

Gerhard Huth

Peter Scharner

Anton Kling

Botho Ziegenbein

Peter Nolting

Martin Holland

Guenther Stecher

Helmut Janku

Winfried Gillert

Method for determining small quantities of carbon monoxide and nitrogen

Catalytic coating for cooking surfaces

Sensor for determining carbon monoxide

A gas sensor device has a carrier plate of ceramic or glass. The carrier has apertures which leave only strips in a spiral configuration connecting a middle region of the carrier to the outer region thereof. The apertures may be mere slits separating the connection strips or they may be apertures providing larger air gaps. On each middle region so provided on the carrier a sensor element is located that has two electrodes and a sensitive layer which establishes a conducting connection between the electrodes. The electrodes and the sensitive layer are directly applied to the upper surface of the middle region. The two electrodes are comb shaped and are placed in inter-digital configuration to define a meandering gap between them. On the underside of the middle region of the carrier a heating element for the sensor element is provided and, if desired, also a temperature measuring resistance for regulating the temperature produced by a heating resistor. Conducting paths are located on the connecting strips between the middle region and the outer region of the carrier for connecting a sensor element and its heater to circuits on the outer region of the carrier plate.

Hot gas sensor device with improved thermal isolation from carrier plate

Ignition device with lowered ignition temperature

The use of zeolites rich in silicic acids having an Si:Al ratio of 1:1 to 100:1 as specific adsorbents for NO.sub.X or CO is proposed. Because of their property of specifically adsorbing NO.sub.X or CO, these zeolites, in particular those zeolites doped with such metals as Ca, Co, Ni, Fe, Cu, Ag, Pt or Ru, and having the above mentioned ratio of Si to Al, are especially suitable for the production of specific NO.sub.X or CO sensors based on semiconductors. Such sensors can be used as sensors for exhaust gases of automotive vehicles, for example.

Zeolites as specific adsorbents for NO.sub.X and CO

To detect substantial deviation of operation of the engine with fuel-air mixtures from stoichiometric relationships, particularly extended operation under very lean or enriched supply mixtures, the exhaust gases are conducted past a first sensor which provides a clearly defined voltage jump upon change of the exhaust gases between reducing and oxidizing state; and, additionally, to a second exhaust gas sensor and preferably to a third sensor, the second and third sensors being, respectively, responsive to the oxygen level in the exhaust gases and to the CO (or hydrocarbon) level in the exhaust gases, respectively, and additionally modifying the relative proportion of fuel and air of the mixture being fed to the engine.

Internal combustion engine exhaust gas monitoring system

Tin oxide doped with magnesium oxide or niobium pentoxide and prepared as a sintered material is found to be highly sensitive to oxygen partial pressure both in the presence of free oxygen and in the presence of oxidizable gases, such as carbon monoxide or the lower oxides of nitrogen, and even in the presence of mixtures of both, such as in the exhaust gas of an internal combustion engine. The electrical conductivity varies by substantially more than an order of magnitude in response to a change in the oxygen partial pressure of about one-half an order of magnitude. The doped oxides operate as poor catalysts for the oxidation of oxidizable components of the exhaust gases. Chromium oxide doped with tin oxide shows the effect of an excessively good catalysis from the point of view of range of measurement, but is usable to give a sharp indication of the appearance or disappearance of free oxygen in a gas mixture. Zinc oxide doped with aluminum oxide has a conductivity that is good for measuring the content of free oxygen, but is of questionable value in the presence of a substantial concentration of carbon monoxide.

Sintered metal oxide semiconductor having electrical conductivity highly

The present invention provides a catalyst for converting the noxous CO, NO.sub.x and hydrocarbons found in the exhaust gases from internal combustion engines into less harmful gases, and to the method of treating said exhaust gases. The catalyst consists essentially of a solid solution of Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, and Fe.sub.3 O.sub.4. The catalyst may be extended on a porous carrier such as aluminum oxide or aluminum silicate. The catalyst is particularly suited for treating the exhaust gas from internal combustion engines of motor vehicles.

Method of treating vehicle exhaust gas and catalyst used therein

Growing community of inventors

Stuttgart, Germany

Detlef Baresel