| 摘要 |
The invention relates to a device for spectroscopically determining concentrations of gases (4) in gaseous mixtures. In the method, periodically alternating monochromatic light (1) of at least two wavelengths is used, and the light (1) of at least one wavelength is characteristic, and the light (1) of at least one other wavelength is uncharacteristic of the transmission of the gas to be determined. This transmission generates electric signals which contain harmonic components of at least one odd Fourier frequence of an emission period of which the amplitude is proportional to the concentration of the gas (4) to be determined in the gaseous mixture and vanishes with the concentration. <IMAGE> |
