The invention relates to a procedure for controlling the reducing agent in an exhaust gas post-processing system of a combustion machine with an exhaust gas duct, in which an SCR catalytic converter is provided in the direction of flow of the exhaust, wherein a reducing agent generation system has an NO.sub.x and CO/H.sub.2 generation unit,, an oxidation catalytic converter and a combined NO.sub.x storage / ammonia generation unit in the standard gas route of the reducing agent generation system, and, in order to reduce nitrogen oxide, ammonia is added as a reducing agent in front of the SCR catalytic converter by the reducing agent generation system, wherein source materials for the generation of ammonia are at least intermittently added to the NO.sub.x and CO/H.sub.2 generation unit via a fuel supply line and via an air supply line, wherein during the fat phase the air/fuel composition is changed in front of the oxidation catalytic converter in the form of a lambda modulation for a lambda value. It can thus be achieved that, in pulse mode, a high H.sub.2/CO yield can be achieved with a simultaneously low HC slip and the higher HC penetrations associated with the natural aging of the catalytic converter and the decreasing H.sub.2/CO yields are compensated. Influences resulting from the reactor geometry of the oxidation catalytic converter can be influences or compensated with the procedure in terms of its drive-away characteristic.

For determining the transit time of an ultrasonic signal from an ultrasonic sensor that was launched into a measurement path by an ultrasonic converter, the phase shift of the ultrasonic signal is determined relative to a reference timing signal, and a remainder is determined as a measure of the transit time of the ultrasonic signal so that the phase shift is determined using a quadrature demodulation scheme, with which the received ultrasonic signal is inverted, in a segmented manner, using a timing signal and a phase-shifted timing signal, and the remainder is determined based on a characteristic quantity of the ultrasonic signal.

A power table saw of the type which has a generally rectangular table with front and rear end portions, a motor operatively coupled to drive a rotary cutting blade extending upwardly through a top of the table, the table saw including an elongated fence having front and rear end portions, and being configured to be laterally movable along the width of the table and be secured to the front and rear end portions of the table, front and rear releasable locking mechanisms operatively associated with the front and rear end portions of the fence for locking each end portion to the end portions of the table, and at least one positional sensor provided with each of the front and rear end portions of the fence for determining the lateral position of each end portion of the fence along the width of the table.

A packaging unit is provided, especially for a wiper blade. The packaging unit has a container for receiving at least one object and a casing that is able to be slid over the container, the casing covering the container at least partially. The casing has a section having a narrowed cross section, so that, in the area of the section, the casing exerts a clamping force on the container.

An accessory with a hub for mounting on rotary tool mandrels of different types is disclosed. In one embodiment, the rotary tool accessory includes a work portion and a hub portion operably connected to the work portion for rotating the work portion. The hub portion includes a first mandrel mounting portion on a first side of the hub portion for mounting with a first mandrel type and a second mandrel mounting portion on a second side of the hub portion for mounting with a second mandrel type, wherein the second mandrel type is different from the first mandrel type.