Ammonia detection by using quantum-cascade laser photoacoustic spectroscopy |
| |
Authors: | Filho Milton B da Silva Marcelo G Sthel Marcelo S Schramm Delson U Vargas Helion Miklós Andras Hess Peter |
| |
Affiliation: | Laboratório de Ciências Físicas, Centro de Ciência e Technologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes-RJ, Brazil. |
| |
Abstract: | A pulsed quantum-cascade distributed-feedback laser, temperature tunable from -41 degrees C to +31.6 degrees C, and a resonant differential photoacoustic detector are used to measure trace-gas concentrations to as low as 66 parts per 10(9) by volume (ppbv) ammonia at a low laser power of 2 mW. Good agreement between the experimental spectrum and the simulated HITRAN spectrum of NH3 is found in the spectral range between 1046 and 1052 cm(-1). A detection limit of 30 ppbv ammonia at a signal-to-noise ratio of 1 was obtained with the quantum-cascade laser (QCL) photoacoustic (PA) setup. Concentration changes of approximately 50 ppbv were detectable with this compact and versatile QCL-based PA detection system. The performance of the PA detector, characterized by the product of the incident laser power and the minimum detectable absorption coefficient, was 4.7 x 10-9 W cm(-1). |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|