Moist Air - Degree of Saturation

Humidity ratio of moist air to humidity ratio of saturated moist air. The Degree of Saturation is the ratio of the humidity ratio of moist air to the humidity ratio of saturated moist air at the same temperature and pressure.

Calculator

Inputs

Calculation Method

Humidity Ratio (x) (kgH2O/kgdry_air)

Humidity Ratio at Saturation (xs) (kgH2O/kgdry_air)

Relative Humidity (φ) (%)

Vapor Pressure (pw) (mbar)

Saturation Vapor Pressure (pws) (mbar)

Atmospheric Pressure (pa) (mbar)

Results

Degree of Saturation (μ)-- -

Method	Input Parameter 1	Input Parameter 2	Input Parameter 3	Degree of Saturation (μ)
Humidity Ratio	x = 0.01 kgH2O/kgdry_air	xs = 0.02 kgH2O/kgdry_air	-	0.50
Humidity Ratio	x = 0.015 kgH2O/kgdry_air	xs = 0.025 kgH2O/kgdry_air	-	0.60
Pressure	φ = 60%	pw = 15 mbar	pws = 25 mbar, pa = 1013.25 mbar	0.59
Pressure	φ = 80%	pw = 20 mbar	pws = 25 mbar, pa = 1013.25 mbar	0.79

Formulas

Method 1 - Humidity Ratio:

μ = x / xs

where:

μ = degree of saturation
x = humidity ratio of the air (kgH2O/kgdry_air)
xs = humidity ratio of the air at saturation (kgH2O/kgdry_air)

Method 2 - Pressure-based:

μ = φ × (pa - pws) / (pa - pw)

where:

μ = degree of saturation
φ = relative humidity (%)
pw = vapor pressure (mbar)
pws = saturation vapor pressure (mbar)
pa = atmospheric pressure (mbar)

Moist Air - Degree of Saturation | MEPKit Engineering Tools | MEPKit