Variable pressure infrared diode laser spectroscopy: a new method for trace-gas monitoring.
A new method for measuring trace concentrations of atmospheric pollutants by infrared diode laser spectroscopy has been devised. This method relies on the increase of the signal as the pressure inside the cell increases, while the frequency of the diode is stabilized on the line, even if it is unresolved. Performances of this method were tested with N2O and with 1,3-butadiene. As an example of application, we measured the butadiene emitted by car exhausts. Sensitivity and rapidity of this method are equivalent to the usual scanning method in which the whole line is described, but this new method benefits from its simplicity and robustness.
Unité Mixte de Recherche 8522, Centre d'Etudes et de Recherches Lasers et Applications, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
Sébastien
S
Dusanter
Bernard
B
Lemoine
Benjamin
B
Hanoune
Pascal
P
Devolder