Abstract: Method and device for regulating the NO.sub.x emission of an internal combustion engine. It has been found that the NO.sub.x emission is dependent on the efficiency of the engine. That is to say the NO.sub.x emission can be optimized by determining and controlling the efficiency. This can be performed by making the measured and determined efficiencies equal to one another by altering the air/fuel ratio.

Abstract: Spark gap measuring and monitoring method and device, for providing, during operation, a signal indicative of the intended performance of the spark gap (1), in particular a spark plug of a combustion engine. The device includes an electrical detecting element which is coupled inductively to a connecting lead (4) of the spark gap (1), for example a toroidal coil (8), which detecting element is connected to a processing circuit (9-11) for the purpose of converting the electrical signal produced by the detecting element into a measuring signal indicative of the spark gap (1) performance, for example the spacing (d) between the electrodes (2, 3). Measurement results obtained from an initial measurement can be established as reference data by means of memory elements and circuit elements. The measuring signal is then analyzed by means of an analyzing circuit (14) as a function of the reference data.

Abstract: A control system for supplying a gas flow to a gas consumption apparatus, comprising a gas supply pipe which can be connected to the apparatus and which has an electrically controlled gas control valve, and an electronic control unit. The control unit comprises a mathematical module, model-related to the control valve, for adjusting the valve position, and the gas control valve has in-built sensors for gas variables and valve position, the control system adjusting the control valve in linear proportion to a desired gas-flow signal to be supplied to the control unit. The mathematical module comprises a flow submodule, a mechanical submodule and a valve-position submodule, and the flow submodule receives, at its inputs, the desired gas-flow signal and gas variables originating from the valve sensors and supplies, at its output, a signal relating to the through-flow area of the valve, to the mechanical submodule.