What techniques are used for gas analysis instrumentation?

Gas analysis techniques include: Infrared absorption (NDIR - measures CO, CO2, hydrocarbons based on characteristic absorption), Paramagnetic (oxygen measurement using O2's paramagnetic property), Electrochemical cells (toxic gas detection, consume analyte in chemical reaction), Catalytic bead (combustibles measurement via oxidation heat), Thermal conductivity (binary mixtures, H2 detection), Flame ionization (hydrocarbon detection with high sensitivity), and Tunable diode laser (TDLAS - specific gas species, fast response). Selection depends on: gas species, concentration range, response time, specificity, cross-sensitivity, and environment. Sample conditioning (filtering, drying) is often required.