When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Useful conversions and formulas for air dispersion modeling

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

    = air pollutant concentration, in parts per million by volume mg/m 3 = milligrams of pollutant per cubic meter of air = atmospheric temperature in kelvins = 273.15 + °C 0.08205 = Universal Gas Law constant in atm·l/(mol·K) = molecular weight of the air pollutant (dimensionless)

  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. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    At 10 000 ppm the solution is a deep red colour. As the concentration decreases the colour becomes orange, then a vibrant yellow, with the final 1 ppm sample a very pale yellow. 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 ...

  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. 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 ...

  7. Threshold limit value - Wikipedia

    en.wikipedia.org/wiki/Threshold_limit_value

    Its units are in parts per million (ppm) for gases and in milligrams per cubic meter (mg/m 3) for particulates such as dust, smoke and mist. The basic formula for converting between ppm and mg/m 3 for gases is ppm = (mg/m^3) * 24.45 / molecular weight. This formula is not applicable to airborne particles.

  8. Mass fraction (chemistry) - Wikipedia

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

    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 the unit "%" can only be used for dimensionless quantities. Instead, the concentration should simply be given in units of g/mL.

  9. Template:Parts per million - Wikipedia

    en.wikipedia.org/wiki/Template:Parts_per_million

    Toggle the table of contents. Template: Parts per million. 18 languages. ... → 0.123 ppm This page was last edited on 7 July 2024, at 01:15 (UTC). Text is ...