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Quantum Cascade Laser-Based Photoacoustic Sensor for Trace Detection of Formaldehyde Gas
We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH(2)O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 μm. A resonant photoacoustic cell, equipped with four electret microphones, is excited in its...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Molecular Diversity Preservation International (MDPI)
2009
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3348822/ https://www.ncbi.nlm.nih.gov/pubmed/22574040 http://dx.doi.org/10.3390/s90402697 |
Sumario: | We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH(2)O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 μm. A resonant photoacoustic cell, equipped with four electret microphones, is excited in its first longitudinal mode at 1,380 Hz. The absorption line at 1,778.9 cm(−1) is selected for CH(2)O detection. A detection limit of 150 parts per billion in volume in nitrogen is achieved using a 10 seconds time constant and 4 mW laser power. Measurements in ambient air will require water vapour filters. |
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