Abstract: Two methods are provided for monitoring the catalytic activity of a catalytic converter arranged in the exhaust gas conduit of a motor vehicle. According to one method, proceeding from a cold start, a temperature progression is determined by a temperature sensor arranged downstream of the catalytic converter and a temperature plateau is thereby determined; the length of the temperature plateau is compared with the length of a temperature plateau determined in advance on a new catalytic converter; a shortening of the length of the measured temperature plateau is interpreted as an aging of the catalytic converter; and the catalytic converter is judged as defective if the shortening exceeds an established limiting value.

Abstract: A connection arrangement is provided for a mineral-insulated conduit with two ends to at least one tube-shaped structure, wherein at least one end is arranged partially overlapping with a tube-shaped structure and is affixed by welding or soldering, and wherein a sheath surface is arranged in the region of the overlap. The problem results of making available a connection arrangement for a mineral-insulated conduit to a tube-shaped structure, which is simple to produce and mechanically stable. The problem is solved in that the sheath surface has a structured surface, the end of the mineral-insulated conduit and the tube-shaped structure contact each other on all sides in the region of the overlap, and the contact surface is smaller than the sheath surface beyond the contact surface.

Abstract: A measuring arrangement is provided with a soot filter for use in flowing, soot particle-bearing gases, as well as a method for monitoring the operability of a soot filter arranged in an exhaust gas conduit, wherein at least one component stream of an exhaust gas stream flows through at least one molded element which is open-pored at least in the flow direction, and wherein the temperature of the molded element is measured with at least one temperature probe. In the measuring arrangement the soot filter is allocated at least one soot sensor, which has at least one molded element which is openpored at least in the flow direction, at least one electric heating element, and at least one temperature probe. The measuring arrangement and method make possible a monitoring of the operability of a soot filter in a reliable and direct manner.

Abstract: A porous electrode structure for a gas sensor, as well as a sensor arrangement, is provided for detecting hydrocarbons in a measured gas. The porous structure guarantees, in addition to a low impedance, a high temporal stability and reproducibility of the measurement signal. The porous electrode structure has a conductive gold framework, which contains oxide components, in particular gallium oxide.