Co Sensor with High Concentrations of H₂O at Elevated Temperature by TDLAS

Abstract

A method of tunable diode laser absorption spectroscopy (TDLAS) is presented to improve the detectability of CO under high temperatures with a mass of interference referred as Dynamic subtract from background technique. By simultaneously fitting both the water background and the 2f-wm-CO curve to the measured (combined) spectrum, the limitation of CO detection is improved at high temperatures using the telecommunication distributed feedback (DFB) lasers. The R14 in the υ=0υ=3 overtone band (1653.6 nm) has been investigated with the dependence of temperatures and water concentrations. Hundreds ppmm of limitation of CO detection can be achieved in media with tens of percent water at 850 °C with an accuracy of a few percent.