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  2. Useful conversions and formulas for air dispersion modeling

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

    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. 1 percent by volume = 10,000 ppmv (i.e., parts per million by volume).

  3. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water.The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution.

  4. 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).

  5. Hydrazine - Wikipedia

    en.wikipedia.org/wiki/Hydrazine

    260 ppm (rat, 4 h) 630 ppm (rat, 1 h) ... approximately 120,000 tons of hydrazine hydrate ... which produce 100–200 mL of gas per gram of precursor.

  6. Saline water - Wikipedia

    en.wikipedia.org/wiki/Saline_water

    Seawater has a salinity of roughly 35,000 ppm, equivalent to 35 grams of salt per one liter (or kilogram) of water. The saturation level is only nominally dependent on the temperature of the water. [1] At 20 °C (68 °F) one liter of water can dissolve about 357 grams of salt, a concentration of 26.3 percent by weight (% w/w). At 100 °C (212 ...

  7. 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).

  8. Total dissolved solids - Wikipedia

    en.wikipedia.org/wiki/Total_dissolved_solids

    where TDS is expressed in mg/L and EC is the electrical conductivity in microsiemens per centimeter at 25 °C. The conversion factor k e varies between 0.55 and 0.8. [5] Some TDS meters use an electrical conductivity measurement to the ppm using the above formula. Regarding units, 1 ppm indicates 1 mg of dissolved solids per 1,000 g of water. [6]

  9. Emission standard - Wikipedia

    en.wikipedia.org/wiki/Emission_standard

    Maximum limits are 2.7 grams per kilometre (4.35 g/mi) of CO, 0.39 grams per kilometre (0.63 g/mi) of HC, and 0.48 grams per kilometre (0.77 g/mi) of NO x. One interesting detail of the Japanese emissions standards was that they were introduced in a soft manner; that is, 1978 model year cars could be sold that did not meet the 1978 standards ...