### Description

The humidity of air at a given temperature can be given as the water content or the relative humidity.

The water content of air is measured with a hygrometer and is reported in mg/L.

relative humidity at °C =

= (measured water content in mg/L at °C) / (absolute humidity at °C when saturated) * 100%

 Temperature in °C Absolute Humidity in mg/L Air When Saturated Water Vapor Pressure in mm Hg at Saturation 19 16.3 16.5 20 17.3 17.5 21 18.4 18.6 22 19.4 19.8 23 20.6 21.0 24 21.8 22.3 25 23.0 23.7 26 24.4 25.1 27 25.8 26.7 28 27.2 28.3 29 28.8 29.9 30 30.4 31.7 31 32.0 33.6 32 33.8 35.5 33 35.6 37.6 34 37.6 39.8 35 39.6 42.0 36 41.7 44.4 37 43.9 46.9 38 46.2 49.5 39 48.6 52.3 40 51.1 55.1 41 53.7 58.1

If the data in the first 2 columns is analyzed with JMP:

absolute humidity of air when saturated at a given temperature =

= (0.03838 * ((temperature in °C)^2)) - (0.62339 * (temperature in °C)) + 14.521

water vapor pressure of air when saturated at a given temperature =

= (0.046067 * ((temperature in °C)^2)) - (0.8969 * (temperature in °C)) + 17.155455