Abstract: A spectrometer (10) for gas analysis is provided, the spectrometer comprising a measurement cell (28) having a gas to be investigated, a light source (12) for the transmission of light (14) into the measurement cell (28) on a light path (16), a filter arrangement (22) having a Fabry-Perot filter (24a-c) in the light path (16), in order to set frequency properties of the light (14) by means of a transmission spectrum of the filter arrangement (22), as well as a detector (36, 38) which measures the absorption of the light (14) by the gas (30) in the measurement cell (28). In this connection the filter arrangement (22) has a plurality of Fabry-Perot filters (24a-c) arranged behind one another in the light path (14) and a control unit (44) for the filter arrangement (22) is provided in order to change the transmission spectrum by setting at least one of the Fabry-Perot filters (24a-c).

Abstract: The invention relates to a spectrometer having a plurality of dispersive optical elements arranged such that electromagnetic radiation entering into the spectrometer is incident on the dispersive optical elements to be split spectrally there; the dispersive optical elements differ from one another with respect to their spatial positions and/or their spectral splitting capabilities; the dispersive optical elements are arranged such that the spectra generated by the respective dispersive optical elements by the splitting of the electromagnetic radiation extend in the same direction and are adjacent to one another transversely to this direction of the spectral splitting; and a detector resolving spatially in two dimensions and being located in the optical path of the split electromagnetic radiation for the detection of at least some respective part sections of the spectra.

Abstract: A gas measurement device for measuring the concentration of a plurality of gas components by means of absorption measurement comprising a light source for infrared radiation (3) or a thermal radiator (4) as a light source (5), an optics (22) for bundling the light of the light source (5), a band pass filter (4) and a photoacoustic measurement cell (12) for measuring a plurality of gas concentrations, wherein a Fabry-Perot filter (6) is provided in front of the photoacoustic measurement cell (12) in addition to the band pass filter (4) for selecting the absorption spectra.

Abstract: The invention relates to a measurement apparatus for the determination of gas concentrations. The apparatus comprises two spectral channels, wherein the channels are separated by a single chopper wheel. The chopper wheel has several functions. On the transmitting side, it brings the light of the two light sources on the same measuring path, on the receiving side it associates the light to the associated receiver; it has its chopper function to use the lock-in technique; and it opens the possibility to implement an easy zero point correction.

Abstract: A method of determining a concentration of a gas in a sample and/or the composition of a gas using a spectrometer comprises transmitting of radiation whose wavelength substantially continuously runs through a wavelength range, wherein the continuous running through of the wavelength range is overlaid by a wavelength modulation; measuring of an absorption signal as a function of the wavelength of the radiation; converting of the absorption signal into first and second derivative signals; deriving of a first and a second measured gas concentration value from the first and the second derivative signals, respectively; and determining of the concentration and/or the composition of the gas from at least the first measured gas concentration value, wherein the wavelength modulation is adapted in response to a change of a state variable of the gas such that a ratio between the first and the second measured gas concentration values is kept substantially constant.

Abstract: A spectrometer (10) for gas analysis is provided, the spectrometer comprising a measurement cell (28) having a gas to be investigated, a light source (12) for the transmission of light (14) into the measurement cell (28) on a light path (16), a filter arrangement (22) having a Fabry-Perot filter (24a-c) in the light path (16), in order to set frequency properties of the light (14) by means of a transmission spectrum of the filter arrangement (22), as well as a detector (36, 38) which measures the absorption of the light (14) by the gas (30) in the measurement cell (28). In this connection the filter arrangement (22) has a plurality of Fabry-Perot filters (24a-c) arranged behind one another in the light path (14) and a control unit (44) for the filter arrangement (22) is provided in order to change the transmission spectrum by setting at least one of the Fabry-Perot filters (24a-c).

Abstract: The invention relates to a measurement apparatus for the determination of gas concentrations. The apparatus comprises two spectral channels, wherein the channels are separated by a single chopper wheel. The chopper wheel has several functions. On the transmitting side, it brings the light of the two light sources on the same measuring path, on the receiving side it associates the light to the associated receiver; it has its chopper function to use the lock-in technique; and it opens the possibillity to implement an easy zero point correction.

Abstract: A method of determining a concentration of a gas in a sample and/or the composition of a gas using a spectrometer comprises the transmitting of radiation whose wavelength substantially continuously runs through a wavelength range, wherein the continuous running through of the wavelength range is overlaid by a wavelength modulation; the measuring of an absorption signal from the absorption of the radiation by the gas as a function of the wavelength of the radiation; the converting of the absorption signal into a first and a second derivative signal; the deriving of a first measured gas concentration value from the first derivative signal and of a second measured gas concentration value from the second derivative signal; and the determining of the concentration and/or the composition of the gas from at least the first measured gas concentration value, wherein the wavelength modulation is adapted in response to a change of a state variable of the gas such that a ratio between the first measured gas concentration

Abstract: A gas measurement device for measuring the concentration of a plurality of gas components by means of absorption measurement comprising a light source for infrared radiation (3) or a thermal radiator (4) as a light source (5), an optics (22) for bundling the light of the light source (5), a band pass filter (4) and a photoacoustic measurement cell (12) for measuring a plurality of gas concentrations, wherein a Fabry-Perot filter (6) is provided in front of the photoacoustic measurement cell (12) in addition to the band pass filter (4) for selecting the absorption spectra

Abstract: The invention relates to a gas discharge lamp with a gas discharge tube having a cylindrical discharge region and having two electrodes which are arranged at an outer side of the gas discharge tube. To achieve an improved gas discharge tube having external electrodes with an increased lifetime it is proposed that each electrode has a planar disc shaped holding section which each have a respective opening and in that the cylindrical discharge region is received in the openings in a shape matched manner, wherein the cylinder axis of the cylindrical discharge region lies perpendicular to the planar holding sections.

Abstract: The invention relates to a gas analyzer for measuring the mercury content of a gas having an Hg light source which transmits transmitted light having wavelengths of at least one spectral line of the mercury, a measuring cell in which the gas to be measured is present, a light receiver, an evaluation unit and a test cuvette which can be introduced into the beam path for checking the operability. To provide an improved gas analyzer which can be calibrated in a simple manner as well as a corresponding improved calibration method, provision is made that the test cuvette contains benzol as a test gas.

Abstract: The invention relates to an apparatus for the measurement of the mercury content of a gas the apparatus comprising: a light source for transmitting the spectral lines of mercury along an optical axis, a magnetic field produced by a magnet which magnetic field is aligned perpendicular to the optical axis at a position where the light is generated for the production of ?+, ?? and ? polarized Zeeman components of the spectral lines in a light beam, an optical separation device for separating the Zeeman components which includes a photo-elastic modulator, a measurement cell for the gas to be measured, a light receiver and an evaluation unit for determining the mercury concentration in the gas by means of the amount of light incident on the light receiver.

Abstract: The invention relates to a gas discharge lamp with a gas discharge tube having a cylindrical discharge region and having two electrodes which are arranged at an outer side of the gas discharge tube. To achieve an improved gas discharge tube having external electrodes with an increased lifetime it is proposed that each electrode has a planar disc shaped holding section which each have a respective opening and in that the cylindrical discharge region is received in the openings in a shape matched manner, wherein the cylinder axis of the cylindrical discharge region lies perpendicular to the planar holding sections.

Abstract: An interferometric gas component measurement apparatus has a light source (27), a measurement path (30) which contains the gas components to be measured, a polarizer (11), a double refracting plate arranged with its optical axis at 45.degree. to the polarization direction, two doubly refracting plates (14, 20) arranged with their optical axes at 45.degree. to one another and an analyzer (13). The light which passes through the measurement path is concentrated into an output gap (32) and reflected via a holographic concave grid (33) onto a diode row (22). The thickness of the individual plates is so selected that specific linear combinations of the thicknesses result in phase displacements between the beams polarized perpendicular to one another in the plates, with these phase displacements corresponding to the reciprocal of the quasi-periodic line splitting of selected vibration and/or rotation bands of the gas molecules of the gas components to be measured.