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: 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: 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.