LEDs provide an advantage that no continuum source, choppers or combination thereof can match. Indeed, amplitude stability of pulsed LEDs tends to be better than that of corresponding laser diodes. Concerning the implemented chamber, the choice fell on a single stepbased resonant cell, even if, in some features, this kind of cell has the advantage of having a volume greater than of a non-resonant one, and this limits its use for small and compact systems for on-site monitoring of gaseous species