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  2. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    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.

  3. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    Some express the concentrations as ppmv (parts per million by volume) and some express the concentrations as mg/m 3 (milligrams per cubic meter), while others require adjusting or correcting the concentrations to reference conditions of moisture content, oxygen content or carbon dioxide content.

  4. Ambient air quality criteria - Wikipedia

    en.wikipedia.org/wiki/Ambient_air_quality_criteria

    Criteria can be set in different units (e.g. μg/m 3, parts per billion by volume (ppbv), parts per billion by mass (ppb (mass)), parts per million (ppm)) and it is possible to convert between all of these units if the molecular mass of the pollutant and the temperature are known. Different standard temperatures are used throughout the world ...

  5. Air pollution measurement - Wikipedia

    en.wikipedia.org/wiki/Air_pollution_measurement

    The amount of pollutant present in air is usually expressed as a concentration, measured in either parts-per notation (usually parts per billion, ppb, or parts per million, ppm, also known as the volume mixing ratio), or micrograms per cubic meter (μg/m³).

  6. List of conversion factors - Wikipedia

    en.wikipedia.org/wiki/List_of_conversion_factors

    Celsius heat unit (International Table) CHU IT: ≡ 1 BTU IT × 1 K/°R = 1.899 100 534 716 × 10 3 J: cubic centimetre of atmosphere; standard cubic centimetre: cc atm; scc ≡ 1 atm × 1 cm 3 = 0.101 325 J: cubic foot of atmosphere; standard cubic foot: cu ft atm; scf ≡ 1 atm × 1 ft 3 = 2.869 204 480 9344 × 10 3 J: cubic foot of natural ...

  7. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    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

  8. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    At 1 ppm the solution is a very pale yellow. As the concentration increases the colour becomes a more vibrant yellow, then orange, with the final 10,000 ppm a deep red colour. In science and engineering , the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities , e.g. mole fraction or ...

  9. Template:Convert/list of units - Wikipedia

    en.wikipedia.org/wiki/Template:Convert/list_of_units

    The table below lists units supported by {{convert}}. More complete lists are linked for each dimension. For a complete list of all dimensions, see full list of units. {{Convert}} uses unit-codes, which are similar to, but not necessarily exactly the same as, the usual written abbreviation for a given unit. These unit-codes are displayed in ...