Verfahren und Anordnung zur Driftkorrektur zeitdiskreter Messsignale bezogen auf ein Referenzsignal, insbesondere in der absorptionsspektroskopischen Spurengasanalytik

The invention relates to a process and a setup for correcting the drift of time-discrete measuring signals referred to a reference signal, in particular for use in absorption-spectroscopic trace gas analysis. By means of the invention, the accuracy of measuring signals obtained from a large number of spectra and scans can be increased. An on-line drift correction is provided for this, and can be used in particular for spectroscopy using semiconductor diode lasers, as well as all other measuring processes in which signal drift results in an impairment of the test result. Due to the fact that on-line analysis and correction of the relative shift between the measuring and calibration spectra and the reference signal is performed before the data are summarized by means of averaging, the otherwise necessary storage of large numbers of unprocessed spectra for later off-line analysis can be avoided. The on-line drift correction process according to the invention can be implemented by using on ly hardware or only software as well as by means of a combination of hardware and software.