- particles (as PM10, PM2.5) – micrograms per cubic metre (µg/m3)
- NEPH or visibility – while commonly written as 'bsp' NEPH is reported in units of 10-4 m-1. This means that a NEPH value of 1.5 should be read as 1.5x10-4 m-1.On multiplying by 100 you can convert this number to the widely used unit for visibility known as inverse megametres (Mm-1).
- gases – parts per million (ppm) for CO and parts per hundred million (pphm) for others. Gaseous concentration values are reported referenced to a temperature of 0°C and an absolute pressure of 101.325 kilopascals. This conversion table will allow you to compare data in the DPE air quality monitoring reports with those from other sources.
Pollutant |
Concentration units we report in… |
to convert from our reported units to… |
multiply by |
---|---|---|---|
Ammonia | pphm | µg/m3 (0°C) µg/m3 (25°C) |
7.6 7.0 |
Ozone |
pphm |
µg/m3 (0°C) |
21.4 |
Nitric oxide (NO) |
pphm |
µg/m3 (0°C) |
13.4 |
Nitrogen dioxide (NO2) |
pphm |
µg/m3 (0°C) |
20.5 |
Sulfur dioxide (SO2) |
pphm |
µg/m3 (0°C) |
28.6 |
Lead |
µg/m3 (0°C) |
µg/m3 (25°C) |
0.92 |
Carbon monoxide |
ppm |
mg/m3 (0°C) |
1.25 |
NEPH or visibility | 10-4 m-1 | Mm-1 or inverse megametres | 100 |