Table 1.

Air pollutants under test.

Pollutant Gas	Concentration (ppm)	Column Density (ppm·m)	Bandwidth (cm${}^{-1}$)
CH${}_4$	600	258	2700–3200
N${}_2$O	250	107.5	2100–2300
C${}_3$H${}_8$	500	215	2700–3200