We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH2O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 mm. 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 CH2O 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.
|Titolo:||Quantum Cascade Laser-Based Photoacoustic Sensor for Trace Detection of Formaldehyde Gas|
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||10.3390/s90402697|
|Appare nelle tipologie:||1.1 Articolo in rivista|