Table 2.

Comparison of the main figures of merit for the two detection modules. The values given were obtained for an optical power of 40 mW and an integration time of 1 s (corresponding to 78 mHz bandwidth).

Detection module	NEC (ppb)	${\alpha }_{min}\left(\text{c}{\text{m}}^{-1}\right)$	NNEA $\left(\text{W}{\text{c}\text{m}}^{-1}{\text{H}\text{z}}^{-1/2}\right)$
QEPAS	22	$1.13\cdot {10}^{-6}$	$1.6\cdot {10}^{-7}$
PTS	53	$2.69\cdot {10}^{-6}$	$3.8\cdot {10}^{-7}$