Entwicklung von Zweikomponentenverfahren für die nichtdispersive IR-Spektroskopie (NDIR) mit Hilfe von chemometrischen Methoden
Spectroscopical procedures are well proven over years analysing solids, fluids and gaseous substances because of their high selectivity, sensitivity and their short response time. They allow continuous and non-destructive measurements wherefore the nondispersive spectroscopy (NDIR) is well locatet in the field of industrial gas analysis. In nondispersive spectrometers which were exclusively used for gas analysis no monochromator or modulator is used but selective detektors. Those detectors, nearly all of them are opto-pneumatical, are filled with the gas which should be measured. In the context of my work it was tried for the first time to analyse a mixture of two gaseous compounts with only one opto-pneumatical detector. For the two choosen mixtures of CO/CO2 und SO2/H2O it was tried to develop a new analysis method for each component while taking spactal data from databases, simulation tools and chemometrical, i.e. mathematical-statistical models. Therefore not only the intensity of the signals were used but the phase of the signals, too. Taking pure gas data calculative mixtures has been build. Afterwards they have been analysed by computer sumulated calculations. Based on these raw data calibration models were build and validated by pure gas and mixtures. In the available work the proof could successfully be made that also the NDIR spectroscopy in combination with chemometric can be used. The application possibilities cover the building of quantitative calibration models for the gas components which can be determined, as well as the determination of the filling gas condition of the detector. Thus could be pointed out in the form of simulation calculations for the first time, how by consideration of signal phases and amplitudes a genuine two-component analysis with a non-dispersive procedure can be accomplished.