Saturation vapor density
Humidity and hygrometry |
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Specific concepts |
General concepts |
Measures and instruments |
The saturation vapor density (SVD) is the maximum density of water vapor in air at a given temperature.
For low temperatures (below approximately 400 K), SVD can be approximated from the SVP by the ideal gas law: P V = n R T where P is the SVP, V is the volume, n is the number of moles, R is the gas constant and T is the temperature in kelvins. The number of moles is related to density by n = m / M, where m is the mass of water present and M is the molar mass of water[clarification needed] (18.01528 grams/mole). Thus, we get P M/R T = m/V = density.
The values shown at hyperphysics-sources[2] indicate that the saturated vapor density is 4.85 g/m3 at 273 K, at which the saturated vapor pressure is 4.58 mm of Hg or 610.616447 Pa (760 mm of Hg ≈ 1 atm = 1.01325 * 105 Pa).
References
- ^ "Absolute Humidity vs. Relative Humidity: Formulas & Conversion". Study.com. Retrieved 1 September 2021.
- ^ "Water Vapor and Vapor Pressure".