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  2. Useful conversions and formulas for air dispersion modeling

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

    1 Nm 3 of any gas (measured at 0 °C and 1 atmosphere of absolute pressure) equals 37.326 scf of that gas (measured at 60 °F and 1 atmosphere of absolute pressure). 1 kmol of any ideal gas equals 22.414 Nm 3 of that gas at 0 °C and 1 atmosphere of absolute pressure ... and 1 lbmol of any ideal gas equals 379.482 scf of that gas at 60 °F and ...

  3. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Therefore, it is common to equate 1 kilogram of water with 1 L of water. Consequently, 1 ppm corresponds to 1 mg/L and 1 ppb corresponds to 1 μg/L. Similarly, parts-per notation is used also in physics and engineering to express the value of various proportional phenomena. For instance, a special metal alloy might expand 1.2 micrometers per ...

  4. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    As an example, a measured NO x concentration of 45 ppmv in a dry gas having 5 volume % O 2 is: 45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv of NO x. when corrected to a dry gas having a specified reference O 2 content of 3 volume %. Note: The measured gas concentration C m must first be corrected to a dry basis before using the above equation.

  5. 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]

  6. Permissible exposure limit - Wikipedia

    en.wikipedia.org/wiki/Permissible_exposure_limit

    Like OSHA, Mine Safety and Health Administration (MSHA) also uses the same 5 decibel exchange rate and 90 dBA for an 8-hour TWA for their PEL. Once a miner's noise exposure exceeds the PEL, feasible engineering AND administrative controls must be in place to try to limit the noise exposure of the employees.

  7. gc (engineering) - Wikipedia

    en.wikipedia.org/wiki/Gc_(engineering)

    In unit systems where force is a derived unit, like in SI units, g c is equal to 1. In unit systems where force is a primary unit, like in imperial and US customary measurement systems, g c may or may not equal 1 depending on the units used, and value other than 1 may be required to obtain correct results. [2]

  8. Grain per gallon - Wikipedia

    en.wikipedia.org/wiki/Grain_per_gallon

    The grain per gallon (gpg) is a unit of water hardness defined as 1 grain (64.8 milligrams) of calcium carbonate dissolved in 1 US gallon of water (3.785412 L). It translates into 1 part in about 58,000 parts of water or 17.1 parts per million (ppm). Also called Clark degree (in terms of an imperial gallon).

  9. Immediately dangerous to life or health - Wikipedia

    en.wikipedia.org/wiki/Immediately_dangerous_to...

    10 ppm: 100447: 77-78-1: 0148: Dimethyl sulfate (used in chemical weapons) [7] 36.1 mg/m 3: 7 ppm: 77781, carcinogenic substance 76-06-2: 0750: Chloropicrin: 13.44 mg/m 3: 2 ppm: 76062: 75-44-5: 0007: Phosgene (used in chemical weapons) 8.1 mg/m 3: 2 ppm: 75445: 5714-22-7-Sulfur pentafluoride ~10.4 mg/m 3: 1 ppm: 5714227: 505-60-2: 0418: Sulfur ...