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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

    1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6. Care must be taken with the concentrations expressed as ppbv to differentiate between the British billion which is 10 12 and the USA billion which is 10 9 (also referred to as the long scale and short scale billion, respectively).

  4. Volume fraction - Wikipedia

    en.wikipedia.org/wiki/Volume_fraction

    It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e.g., 18%. The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients).

  5. Dilution (equation) - Wikipedia

    en.wikipedia.org/wiki/Dilution_(equation)

    V = air or gas volume of the closed space or room in cubic feet, cubic metres or litres; Q = ventilation rate into or out of the room in cubic feet per minute, cubic metres per hour or litres per second; C initial = initial concentration of a vapor inside the room measured in ppm; C final = final reduced concentration of the vapor inside the ...

  6. Carbon dioxide in Earth's atmosphere - Wikipedia

    en.wikipedia.org/wiki/Carbon_dioxide_in_Earth's...

    The concentrations of carbon dioxide in the atmosphere are expressed as parts per million by volume (abbreviated as ppmv, or ppm(v), or just ppm). To convert from the usual ppmv units to ppm mass (abbreviated as ppmm, or ppm(m)), multiply by the ratio of the molar mass of CO 2 to that of air, i.e. times 1.52 (44.01 divided by 28.96).

  7. 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 ...

  8. Concentration - Wikipedia

    en.wikipedia.org/wiki/Concentration

    The volume concentration (not to be confused with volume fraction [3]) is defined as the volume of a constituent divided by the volume of the mixture : =. Being dimensionless, it is expressed as a number, e.g., 0.18 or 18%.

  9. Mass fraction (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Mass_fraction_(chemistry)

    This improper name persists, especially in elementary textbooks. In biology, the unit "%" is sometimes (incorrectly) used to denote mass concentration, also called mass/volume percentage. A solution with 1 g of solute dissolved in a final volume of 100 mL of solution would be labeled as "1%" or "1% m/v" (mass/volume). This is incorrect because ...