Abstract: A process gas analyzer and method for analyzing a process gas carried in a plant section, wherein light from a light source is passed through the process gas and detected via a detector, evaluated in an evaluation unit to produce an analysis result with respect to the absorption in the process gas, where chambers or purging pipes, present between the light source and the plant section and also between the detector and the plant section, are flushed with a purge gas to analyze the process gas, and where the volume flow rate of the purge gas is periodically modulated and the effect of the purge gas on the analysis result is determined based on changes in the detected absorption caused by the modulation and removed from the analysis result to enable a high degree of compensation for measurement errors caused by the purging.

Abstract: Absorption spectrometer and method for measuring the concentration of a gaseous component of interest in a measurement gas, wherein to compensate influence of changes in an optical path length in the absorption spectrometer on a measured result, light from the laser is modulated with at least one pilot frequency in the MHz range, the measurement signal is analyzed in a phase-sensitive manner for the pilot frequency, phase information obtained during this analysis is compared with phase information obtained during calibration of the absorption spectrometer, where the measured result is corrected as a function of the difference between the two items of phase information. Alternatively, light from the laser is modulated with two pilot frequencies, where signal components contained in the measurement signal with the pilot frequencies are detected in a phase-sensitive manner and the difference between the phase information of the two signal components obtained in this operation is analyzed.

Abstract: A method for measuring the concentration of a gas component in a measuring gas. An absorption line of the gas component is varied as a function of the wavelength of the light of a wavelength-tunable light source within a periodically sequential scanning interval. The absorption line of the gas component is modulated with a frequency (f0). Modulated light is guided through the measuring gas onto a detector. A measurement signal generated by the detector is demodulated upon determining a harmonic (nf0) of the frequency (f0). A measurement result is produced by fitting a setpoint curve to the profile of the demodulated measurement signal. Both demodulated measurement signal and setpoint cure are filtered with the aid of the same filter function. The filter function is operative to suppress noise signal components of the demodulated measurement signal that disturb both signal components of the demodulated measurement signal and the setpoint curve.

Abstract: A method for measuring the concentration of a gas component in a measurement gas using a gas analyzer comprises varying the wavelength of the light of a wavelength-tunable light source within periodically consecutive scan intervals for wavelength-dependent scanning of a gas component absorption line of interest. The method also comprises modulating the wavelength of the light of the wavelength-tunable light source with a frequency, guiding the modulated light through the measurement gas onto a detector and demodulating a measurement signal generated by the detector in the event of a harmonic of the frequency. The method further comprises producing a measurement result by fitting a desired curve to the profile of the demodulated measurement signal. A function orthogonal to the desired curve is provided, and an orthogonal component of the measurement result is produced by fitting the orthogonal function to the profile of the demodulated measurement signal.

Abstract: A process gas analyzer and method for analyzing a process gas carried in a plant section, wherein light from a light source is passed through the process gas and detected via a detector, evaluated in an evaluation unit to produce an analysis result with respect to the absorption in the process gas, where chambers or purging pipes, present between the light source and the plant section and also between the detector and the plant section, are flushed with a purge gas to analyze the process gas, and where the volume flow rate of the purge gas is periodically modulated and the effect of the purge gas on the analysis result is determined based on changes in the detected absorption caused by the modulation and removed from the analysis result to enable a high degree of compensation for measurement errors caused by the purging.

Abstract: Absorption spectrometer and method for measuring the concentration of a gaseous component of interest in a measurement gas, wherein to compensate influence of changes in an optical path length in the absorption spectrometer on a measured result, light from the laser is modulated with at least one pilot frequency in the MHz range, the measurement signal is analyzed in a phase-sensitive manner for the pilot frequency, phase information obtained during this analysis is compared with phase information obtained during calibration of the absorption spectrometer, where the measured result is corrected as a function of the difference between the two items of phase information. Alternatively, light from the laser is modulated with two pilot frequencies, where signal components contained in the measurement signal with the pilot frequencies are detected in a phase-sensitive manner and the difference between the phase information of the two signal components obtained in this operation is analyzed.

Abstract: A method for measuring the concentration of a gas component in a measuring gas. An absorption line of the gas component is varied as a function of the wavelength of the light of a wavelength-tunable light source within a periodically sequential scanning interval. The absorption line of the gas component is modulated with a frequency (f0) Modulated light is guided through the measuring gas onto a detector. A measurement signal generated by the detector is demodulated upon determining a harmonic (nf0) of the frequency (f0). A measurement result is produced by fitting a setpoint curve to the profile of the demodulated measurement signal. Both demodulated measurement signal and setpoint cure are filtered with the aid of the same filter function. The filter function is operative to suppress noise signal components of the demodulated measurement signal that disturb both signal components of the demodulated measurement signal and the setpoint curve.

Abstract: A non-dispersive gas analyzer comprising a light source, having light that shines through a measuring cuvette containing a measuring gas to be analyzed onto a non selective detector having a downstream evaluation unit, wherein a multi-component gas analysis is made possible using in a simple manner in that the light source is a flash discharge lamp and the evaluation unit is configured to evaluate the temporal pulse curves of the flash shining onto the detector such that it is possible to take advantage of the property of flash discharge lamps in that the emitted wavelength components vary over the duration of the flash.

Abstract: A method for measuring the concentration of a gas component in a measurement gas using a gas analyzer comprises varying the wavelength of the light of a wavelength-tunable light source within periodically consecutive scan intervals for wavelength-dependent scanning of a gas component absorption line of interest. The method also comprises modulating the wavelength of the light of the wavelength-tunable light source with a frequency, guiding the modulated light through the measurement gas onto a detector and demodulating a measurement signal generated by the detector in the event of a harmonic of the frequency. The method further comprises producing a measurement result by fitting a desired curve to the profile of the demodulated measurement signal. A function orthogonal to the desired curve is provided, and an orthogonal component of the measurement result is produced by fitting the orthogonal function to the profile of the demodulated measurement signal.

Abstract: A method and device for measuring the soot load in the exhaust gas systems of diesel engines using a sensor which is mounted downstream of a particulate filter and comprises a sensor element, to measure the operability of the particulate filter. According to the method, the soot load of the sensor element is measured resistively or capacitively using electrodes. The measuring voltage of the sensor element is controlled depending on at least one actual operating parameter of the diesel engine.

Abstract: A non-dispersive gas analyzer comprising a light source, having light that shines through a measuring cuvette containing a measuring gas to be analyzed onto a non selective detector having a downstream evaluation unit, wherein a multi-component gas analysis is made possible using in a simple manner in that the light source is a flash discharge lamp and the evaluation unit is configured to evaluate the temporal pulse curves of the flash shining onto the detector such that it is possible to take advantage of the property of flash discharge lamps in that the emitted wavelength components vary over the duration of the flash.

Abstract: A modulator wheel of a gas analyzer which contains an opening in the shadowing part thereof, where the opening generates in the measurement signal of the gas analyzer, in addition to a signal component at a modulation frequency generated by alternating shadowing and passing-through of the radiation, a further signal component having twice the modulation frequency that is used for detecting changes to the infrared radiation source or detector arrangement due to contamination, aging, or temperature, and compensating for the effects thereof on the measurement result.

Abstract: A measurement method in which, at the start of a measurement chain, a measured variable is picked up and is further-processed over the course of the measurement chain by conversion to generate a measurement result, where the original or converted measured variable is modulated at a predetermined modulation frequency at a first point in the measurement chain. At a second point in the measurement chain or sequence, which is after the first point in the direction of further-processing, a variable is added to the converted measured variable. The measurement chain or sequence is calibrated using different known values for the measured variable, where different vectors are obtained that define a characteristic, and an unknown value for the measured variable is determined from that point of the characteristic at which the vector obtained in the process or its extension intersects the characteristic.

Abstract: The invention relates to a NDIR two beam gas analyser in which infrared radiation is guided by modulation in an alternating manner through a measuring chamber and a reference chamber and is subsequently detected, a measurement signal being produced due to the analysis which determines the concentration of a measurement gas component present in the measurement chamber.

Abstract: A detector arrangement for detection of a measuring gas component in a gas mixture is provided. The arrangement includes a gas analyzer, a first single-layer receiver and a further single-layer receiver, the first single-layer receiver containing the measuring gas component and the further single-layer receiver containing a transverse gas. A concentration of the measuring gas component in the gas mixture is determined from signals delivered by sensors of the single-layer receivers. An evaluating device includes an n-dimensional calibration matrix for obtaining matrix signal values. Signal values of different known concentrations of the measuring gas component in the presence of different known transverse gas concentrations are stored as n-tubules in the evaluating device.

Abstract: A method and device for measuring the soot load in the exhaust gas systems of diesel engines using a sensor which is mounted downstream of a particulate filter and comprises a sensor element, to measure the operability of the particulate filter. According to the method, the soot load of the sensor element is measured resistively or capacitively using electrodes. The measuring voltage of the sensor element is controlled depending on at least one actual operating parameter of the diesel engine.

Abstract: The invention relates to a NDIR-gas analyser comprising an infrared radiation source (1), a measuring vessel (3) containing a gas mixture (4) having a measuring gas component (5) that is to be detected, and a detector device (7) that is arranged behind the measuring vessel that can detect the influence of ageing of the radiation source (1) and optionally dirt deposits in the optical radiation path without interrupting measuring. According to the invention, at least one optopneumatic detector (15) is arranged in the beam path of the radiation source (1), said detector being filled with any gas (16) when arranged between the radiation source (1) and the measuring vessel (3).

Abstract: The invention relates to a NDIR-gas analyser comprising an infrared radiation source (1), a measuring vessel (3) containing a gas mixture (4) having a measuring gas component (5) that is to be detected, and a detector device (7) that is arranged behind the measuring vessel that can detect the influence of ageing of the radiation source (1) and optionally dirt deposits in the optical radiation path without interrupting measuring. According to the invention, at least one optopneumatic detector (15) is arranged in the beam path of the radiation source (1), said detector being filled with any gas (16) when arranged between the radiation source (1) and the measuring vessel (3).

Abstract: A detector arrangement for detection of a measuring gas component in a gas mixture is provided. The arrangement includes a gas analyzer, a first single-layer receiver and a further single-layer receiver, the first single-layer receiver containing the measuring gas component and the further single-layer receiver containing a transverse gas. A concentration of the measuring gas component in the gas mixture is determined from signals delivered by sensors of the single-layer receivers. An evaluating device includes an n-dimensional calibration matrix for obtaining matrix signal values. Signal values of different known concentrations of the measuring gas component in the presence of different known transverse gas concentrations are stored as n-tubules in the evaluating device.