Abstract: A combination of a measuring sensor and protector having a measuring sensor with a housing and having an elongated cup-like protective pipe engaged with the housing. The pipe has a bottom having a convex shape with an inlet opening. The pipe also has at least one outlet opening spaced away from the bottom. A deflector extends inward from the pipe at an acute angle relative to a longitudinal axis of the pipe and away from the bottom so that when gas flows longitudinally within the pipe from the inlet opening, the gas is deflected by the deflector to flow around the deflector to the at least one outlet opening. The bottom also has a boss-like bulging portion projecting outward to form the inlet opening so as to reduce contamination of the measuring element by preventing solid particles in the gas from entering inside the pipe.

Abstract: A regulating device is proposed for the mixture composition of an internal combustion engine having a signal sensor and having regulating ranges which can be switched over between lambda equals one and the lean range. The lambda-equal-to-one regulation is effected by means of a two-point regulator and the lean regulation is effected either via an altered set-point value of the two-point regulator or with the aid of a steady regulator. The transitions between the two types of regulation take a course dependent on a selectable function, in order to avoid abrupt changes in rpm. A switchover is also made to controlled operation for a brief period at the beginning of each type of regulation.

Abstract: To compensate for temperature-dependent shift on the operating characteristics of an oxygen ion conductive sensor which tends to shift the operating characteristics towards the "lean" range (.lambda.>1) at low temperature, and towards the "rich" range (.lambda.<1) at high temperature, the pulses derived from the sensor are delayed or shifted such that the trailing edge of the pulses, representative of shift from lean to rich direction, is transmitted with delay; dependent on temperature, the shift from rich to lean is also transmitted with delay. The delays are obtained by timing circuits (9, 14) which have variable time delays, the time delay being controlled by a temperature signal (9a) derived by sensing a-c resistance of the sensor, split by a high-pass filter and rectified.

Abstract: To provide for temperature measurement of a solid electrolyte polarographic gas composition sensor, an ac signal is superimposed from an ac voltage source (2) on the applied voltage from a voltage source (1) if the sensor is a polarographic sensor, the ac signal being separated from the output by a filter combination (6, 7), the dc output being evaluated as usual, and the ac output being rectified in a rectifier (9) to obtain a measure of the temperature since the ac resistance (R.sub.alt) is highly temperature dependent (see FIG. 3). The ac preferably is about 10% of the applied dc voltage, so that the voltage swing of the ac potential falls well within the linear range of output current with respect to voltage (see FIG. 2). The output from the ac channel (7, 9) to evaluate the temperature signal can be connected to a control loop circuit (10, 11), including a heater (11) to heat the sensor to maintain a uniform temperature thereof.