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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. Odor detection threshold - Wikipedia

    en.wikipedia.org/wiki/Odor_detection_threshold

    The odor detection threshold is the lowest concentration of a certain odor compound that is perceivable by the human sense of smell.The threshold of a chemical compound is determined in part by its shape, polarity, partial charges, and molecular mass.

  4. 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 ...

  5. Concentration - Wikipedia

    en.wikipedia.org/wiki/Concentration

    ppm, ppb, ppt See also. Dilution ratio – Change in concentration when mixing two liquids; Dose concentration – Ratio of part of a mixture to the whole Serial ...

  6. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    where: 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

  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. Hydrogen sulfide - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_sulfide

    100 ppm IDLH (NIOSH): immediately dangerous to life and health (the level that interferes with the ability to escape) 0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it. [67] 10–20 ppm is the borderline concentration for eye irritation.

  9. Mixed flowing gas testing - Wikipedia

    en.wikipedia.org/wiki/Mixed_flowing_gas_testing

    Mixed Flowing Gas (MFG) test is a laboratory test in which the temperature (°C), relative humidity (%RH), concentration of gaseous pollutants (in parts per billion, ppb or parts per million ppm level), and other critical variables (such as volume exchange rate and airflow rate) are carefully defined, monitored and controlled.