enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Fluorescein aqueous solutions, diluted from 10,000 to 1 parts-per-million in intervals of 10 fold dilution. At 1 ppm the solution is a very pale yellow. 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.

  3. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    mg/m 3 = milligrams of pollutant per cubic meter of air at sea level atmospheric pressure and T: ppmv = air pollutant concentration, in parts per million by volume T = ambient temperature in K = 273. + °C 0.082057338 = Universal gas constant in L atm mol −1 K −1: M = molecular mass (or molecular weight) of the air pollutant

  4. 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).

  5. Drinking water quality standards - Wikipedia

    en.wikipedia.org/wiki/Drinking_water_quality...

    " indicates that no standard has been identified by editors of this article and ns indicates that no standard exists. μg/L = micrograms per litre, or 0.001 ppm; mg/L = 1 ppm, or 1000 μg/L. * means action level; not a concentration standard. A public water system exceeding the action level must implement "treatment techniques" which are ...

  6. Maximum contaminant level - Wikipedia

    en.wikipedia.org/wiki/Maximum_Contaminant_Level

    Maximum contaminant levels (MCLs) are standards that are set by the United States Environmental Protection Agency (EPA) for drinking water quality. [1] [2] An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act (SDWA).

  7. Permissible exposure limit - Wikipedia

    en.wikipedia.org/wiki/Permissible_exposure_limit

    Chemical regulation is sometimes [clarification needed] expressed in parts per million (ppm), but often [clarification needed] in milligrams per cubic meter (mg/m 3). [2] Units of measure for physical agents such as noise are specific to the agent.

  8. Drinking water quality in the United States - Wikipedia

    en.wikipedia.org/wiki/Drinking_water_quality_in...

    EPA published standards in 1991 to ensure that total chromium is limited to 0.1 milligrams per liter or 100 parts per billion in drinking water. It is an odorless and tasteless metal that can be naturally occurring in rocks, plants, soil and volcanic dust, and animals.

  9. Carbonate hardness - Wikipedia

    en.wikipedia.org/wiki/Carbonate_hardness

    An aqueous solution containing 120 mg NaHCO 3 (baking soda) per litre of water will contain 1.4285 mmol/l of bicarbonate, since the molar mass of baking soda is 84.007 g/mol. This is equivalent in carbonate hardness to a solution containing 0.71423 mmol/L of (calcium) carbonate, or 71.485 mg/L of calcium carbonate (molar mass 100.09 g/mol).