Calibration of an open-path FTIR spectrometer for methane, ethylene, and carbon monoxide using a fixed 20-m multipass cell

A calibration experiment was performed by the Fachhochschule Duesseldorf in cooperation with the official calibration laboratory of the Environmental State Agency of Northrhine Westphalia. This was the first calibration of an OP-FTIR spectrometer at an official calibration laboratory in Germany. The calibration measurements were carried out along the standard ISO/DIS 9169, 'air quality - determination of performance characteristics of measurement methods'. A multipass cell with a light path of 20m was used. During these measurements the deviation between the calibration gas concentration and the measured concentration increased rapidly with higher concentration. This indicates a nonlinear calibration function of the OP-FTIR spectrometer used here and might be addressed to the used spectral resolution of 1.0 wavenumbers. The calibration measurements are still running for other gases and other OP-FTIR spectrometers.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.