Diode laser absorption spectroscopy measurement of linestrengths and pressure broadening coefficients of the methane 2ν3 band at elevated temperatures

A diode laser sensor based on absorption spectroscopy has been developed for the measurement of spectroscopic parameters in the R (3) and R (4) manifolds of 2ν3 band of CH4. Individual linestrengths of each transition are determined for a range of temperatures. In addition, collision-broadened half-widths for CO2, N2, H2O, CH4, and CO collision partners are measured as a function of temperature and pressure for these strongly overlapped transitions. From this, temperature dependence of the collision half-width for each collision partner is determined. Using a new method for calculation of collisional broadening at high temperatures for strongly overlapped transitions makes these transitions accessible for spectroscopy.