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  2. 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 ...

  3. Useful conversions and formulas for air dispersion modeling

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

    Here are the conversion factors for those various expressions of wind speed: 1 m/s = 2.237 statute mile/h = 1.944 knots 1 knot = 1.151 statute mile/h = 0.514 m/s 1 statute mile/h = 0.869 knots = 0.447 m/s. Note: 1 statute mile = 5,280 feet = 1,609 meters

  4. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    This article presents methods for converting concentrations from ppmv to mg/m 3 (and vice versa) and for correcting the concentrations to the required reference conditions. All of the concentrations and concentration corrections in this article apply only to air and other gases. They are not applicable for liquids.

  5. 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 ...

  6. Air pollution measurement - Wikipedia

    en.wikipedia.org/wiki/Air_pollution_measurement

    The amount of pollutant present in air is usually expressed as a concentration, measured in either parts-per notation (usually parts per billion, ppb, or parts per million, ppm, also known as the volume mixing ratio), or micrograms per cubic meter (μg/m³).

  7. Total organic carbon - Wikipedia

    en.wikipedia.org/wiki/Total_organic_carbon

    Persulfate methods are used in the analysis of wastewater, drinking water, and pharmaceutical waters. When used in conjunction with sensitive NDIR detectors heated persulfate TOC instruments readily measure TOC at single digit parts per billion (ppb) up to hundreds of parts per million (ppm) depending on sample volumes.

  8. Talk:Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Talk:Parts-per_notation

    The examples don't seem to be too accurate. A drop is usually defined as 0.05 ml, which then gives;. 1 drop in 50 ml = 1‰, 50ml is a very small cup 1 drop in 50 l = 1ppm 50 l is about 11 gallons, not 40 1 drop in 50 cubic metres = 1 ppb 1 drop = 1ppt, a 50 m swimming pool is 50*25*2 = 2,500 m^3 1 drop in 50,000,000 cubic metres = 1ppq, 50,000,000 m^3 is equivalent to a lake covering a square ...

  9. Thermal conductivity detector - Wikipedia

    en.wikipedia.org/wiki/Thermal_conductivity_detector

    The TCD is also used in the analysis of permanent gases (argon, oxygen, nitrogen, carbon dioxide) because it responds to all these substances unlike the FID which cannot detect compounds which do not contain carbon-hydrogen bonds. Considering detection limit, both TCD and FID reach low concentration levels (inferior to ppm or ppb). [2]