Tunable diode-laser absorption measurements of methane at elevated temperatures

Abstract

A diode-laser sensor system based on absorption spectroscopy techniques has been developed to monitor CH(4) nonintrusively in high-temperature environments. Fundamental spectroscopic parameters, including the line strengths of the transitions in the R(6) manifold of the 2ν(3) band near 1.646 μm, havebeen determined from high-resolution absorption measurements in a heated static cell. In addition, acorrected expression for the CH(4) partition function has been validated experimentally over thetemperature range from 400 to 915 K. Potential applications of the diode-laser sensor system includeprocess control, combustion measurements, and atmospheric monitoring.