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  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water.The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution.

  3. Total dissolved solids - Wikipedia

    en.wikipedia.org/wiki/Total_dissolved_solids

    Bottled mineral water usually contains higher TDS levels than tap water.. Total dissolved solids (TDS) is a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular (colloidal sol) suspended form.

  4. PPM - Wikipedia

    en.wikipedia.org/wiki/PPM

    Parts per million, ppm Carbon dioxide in Earth's atmosphere, CO 2 ppm; Peak programme meter, measuring audio level; Planned Preventative Maintenance of equipment; PPM Star Catalogue of 378,910 stars' positions and proper motions; Proton precession magnetometer, measures small magnetic field variations; Pulse-position modulation of a signal

  5. Dilution (equation) - Wikipedia

    en.wikipedia.org/wiki/Dilution_(equation)

    To dilute a solution means to add more solvent without the addition of more solute. The resulting solution is thoroughly mixed so as to ensure that all parts of the solution are identical. The same direct relationship applies to gases and vapors diluted in air for example. Although, thorough mixing of gases and vapors may not be as easily ...

  6. Orders of magnitude (molar concentration) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(molar...

    inhaled carbon monoxide induces unconsciousness in 2–3 breaths and death in < 3 min (12 800 ppm) [15] 10 −3: mM 0.32–32 mM: normal range of hydronium ions in stomach acid (pH 1.5–3.5) [16] 5.5 mM: upper bound for healthy blood glucose when fasting [17] 7.8 mM: upper bound for healthy blood glucose 2 hours after eating [17] 10 −2: cM 20 mM

  7. Concentration - Wikipedia

    en.wikipedia.org/wiki/Concentration

    In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. [1]

  8. 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.

  9. pCO2 - Wikipedia

    en.wikipedia.org/wiki/PCO2

    The pCO 2 of Earth's atmosphere has risen from approximately 280 ppm (parts-per-million) to a mean 2019 value of 409.8 ppm as a result of anthropogenic release of carbon dioxide from fossil fuel burning. [citation needed] This is the highest atmospheric concentration to have existed on Earth for at least the last 800,000 years. [1]