External-cavity diode laser spectrometer for measuring the concentration ratio (CO2)-C-13/(CO2)-C-12 by absorptionin the range of 1.6 mu m

摘要

The method for determining the carbon isotopic ratio from CO2 absorption spectra in the optical cavity containing atmospheric air with the natural contents of carbon dioxide similar to 0.03 % is described. The measurements are performed at atmospheric pressure in the conditions of overlapping absorption lines. The measurement accuracy is 0.3 %.