0 0 OZONE
1 1 WATER VAPOUR
2 2 METHANE
3 3 CARBON DIOXIDE
4 4 CARBON MONOXIDE
5 5 NITROGEN DIOXIDE
6 6 NITROUS OXIDE
7 7 FORMALDEHYDE
8 8 SULPHUR DIOXIDE
25 25 PARTICULATE MATTER < 1.0 MICRONS
26 26 PARTICULATE MATTER < 2.5 MICRONS
27 27 PARTICULATE MATTER < 10 MICRONS
28 28 AEROSOLS (GENERIC)
29 29 SMOKE (GENERIC)
30 30 CRUSTAL MATERIAL (GENERIC DUST)
31 31 VOLCANIC ASH
255 255 MISSING VALUE
