Ammonia Monitoring Near 1.5 mum with Diode-Laser Absorption Sensors

We investigated ammonia spectroscopy near 1.5 mum to select transitions appropriate for trace ammonia detection in air-quality and combustion emissions-monitoring applications using diode lasers. Six ammonia features were selected for these trace-gas detection applications based on their transition strengths and isolation from interfering species. The strengths, positions, and lower-state energies for the lines in each of these features were measured and compared with values published in the literature. Ammonia slip was measured in the exhaust above an atmospheric pressure premixed ethylene-air burner to demonstrate the feasibility of the in situ diode-laser sensor.