Search results
Results from the WOW.Com Content Network
0.1 × ( 12 ÷ 8 ) = 0.15 grain per dscf when corrected to a gas having a specified reference CO 2 content of 12 volume %. Notes: Although ppmv and grains per dscf have been used in the above examples, concentrations such as ppbv (i.e., parts per billion by volume), volume percent, grams per dscm and many others may also be used.
As an example, a measured particulates concentration of 200 mg/m 3 in a dry gas that has a measured 8 volume % CO 2 is: 200 × ( 12 ÷ 8 ) = 300 mg/m 3. when corrected to a dry gas having a specified reference CO 2 content of 12 volume %.
9 ppm (10 mg/m 3) 8-hour Not to be exceeded more than once per year 40 CFR 50.8: Ozone (O 3) Primary and Secondary 0.12 ppm (235 μg/m 3) 1-hour a: expected number of days per calendar year, with maximum hourly average concentration greater than 0.12 ppm, is equal to or less than 1 40 CFR 50.9: Primary and Secondary 0.070 ppm (140 μg/m 3) 8-hour
Carbon monoxide 8 hours 9 ppm Nitrogen dioxide 1 hour 0.12 ppm 1 year 0.03 ppm Ozone 1 hour 0.10 ppm 4 hours 0.08 ppm Sulfur dioxide 1 hour 0.20 ppm 1 day 0.08 ppm 1 year 0.02 ppm Lead 1 year 0.50 μg/m 3: PM 10 1 day 50 μg/m 3: 1 year 25 μg/m 3: PM 2.5 1 day 25 μg/m 3: 1 year 8 μg/m 3
The early standards mainly concerned carbon monoxide (CO) and hydrocarbons (HC). Regulations on nitrogen oxide emissions (NO x) were introduced in the United States, Japan, and Canada in 1973 and 1974, with Sweden following in 1976 and the European Economic Community in 1977. These standards gradually grew more and more stringent but have never ...
Urban air quality index (AQI) values are computed by combining or comparing the concentrations of a "basket" of common air pollutants (typically ozone, carbon monoxide, sulfur dioxide, nitrogen oxides, and both fine and coarse particulates) to produce a single number on an easy-to-understand (and often colour-coded) scale. [63]
Ventilation air methane thermal oxidizers are used to destroy methane in the exhaust air of underground coal mine shafts. Methane is a greenhouse gas and, when oxidized via thermal combustion, is chemically altered to form CO 2 and H 2 O. CO 2 is 25 times less potent than methane when emitted into the atmosphere with regards to global warming ...
Composition of dry atmosphere, by volume [ note 1] [ note 2]; Gas (and others): Various [1]: CIPM-2007 [2]: ASHRAE [3]: Schlatter [4]: ICAO [5]: US StdAtm76 [6]: Tap ...