Abstract: A method for identifying R-waves in an ECG signal for the purpose of triggering further measurements or examinations is proposed. A reference ECG signal by an ECG measuring device is measured. An R-wave in the reference ECG signal is identified. A reference quantity is determined from the reference ECG signal. The reference ECG signal assumes in a time interval that starts before the R-wave of the ECG signal and lasts at a maximum up to the occurrence of the R-wave. A comparison rule is generated based on the reference quantity. ECG signals are measured in which R-waves are to be identified. The measured ECG signals are compared with the reference quantity based on the comparison rule. A trigger signal is outputted based on a positive result of the comparison.

Abstract: The NOx concentration in a gas is determined with a thick-film measuring sensor which has two measuring cells. The raw measured value of the measuring sensor is corrected by a multiplicative correction value and an additive correction value, which are both taken from a characteristic map. The characteristic map depends on the oxygen-ion pumping current in the second measuring cell, the measured gas temperature, and the measuring sensor temperature.

Abstract: A method is provided for checking the dynamic behavior of a measuring sensor which detects a substance concentration in the exhaust tract of an internal combustion engine operating with excess air, downstream of an NOx storage catalytic converter. A signal from the measuring sensor is monitored during a regeneration phase. When a predetermined signal profile is absent, a faulty dynamic behavior is diagnosed.

Abstract: A circuit configuration for generating a virtual ground includes a micro-controller, an analog circuit and a read-only memory. A pulse-width modulated signal, which is output by the micro-controller, is converted, by using the analog circuit, into the virtual ground as a common reference potential of an exhaust probe which operates according to the principle of the galvanic oxygen concentration cell with a solid electrolyte. The actual value of the virtual ground is read into the micro-controller through the use of an A/D converter and is compared with a predefined setpoint value. The potential value of the virtual ground is then controlled on the basis of the difference value. An exhaust probe configuration is also provided.

Abstract: A circuit configuration for controlling a pump current includes a microcontroller, an analog circuit and a read-only memory. A pulse-width modulated signal, which is output by the micro-controller, is converted, by using the analog circuit, into the pump current for a pump cell of an exhaust probe which operates according to the principle of the galvanic oxygen concentration cell with a solid electrolyte. A pump current actual value is determined from a voltage drop across a measuring resistor, and a pump current setpoint value is determined from a voltage difference between an actual value of a Nernst voltage in the corresponding measuring cell and a predefined setpoint value. An exhaust probe configuration is also provided.

Abstract: A NOx concentration of a gas is measured with a NOx measuring sensor which has two measuring cells. An oxygen concentration is respectively corrected by a oxygen-ion pumping current. A controller is used for correcting a transitional resistance through which the first oxygen-ion pumping current flows at the first measuring cell, the controller correcting at least partially a correction value for the transitional resistance by using the second oxygen-ion pumping current at the second measuring cell.

Abstract: A control circuit of an exhaust probe has a microcontroller and an analog circuitry. Measured values which are recorded in a test chamber under predefined test conditions are stored in characteristic maps in a programmable read-only memory. These values are then used as a reference for a subsequent recalibration of a probe system.

Abstract: The present invention includes a method and apparatus for cleaning exhaust of an internal combustion engine. The internal combustion engine has a catalyst and a lambda probe disposed in an exhaust gas tract. The lambda probe is disposed upstream from the catalyst, and is capable of an output &lgr;o substantially close to lambda=1. The present invention includes determining a relationship between a downstream NOx concentration and a lambda value such that a lambda value substantially greater than 1 indicates a substantially greatly increased NOx concentration, and determining a relationship between a downstream NH3 concentration and a lambda value such that a lambda value substantially less than 1 indicates a substantially greatly increased NH3 concentration.