Formulae
Definition of aw:
where p is the vapor pressure of water in the substance, and p₀ is the vapor pressure of pure water at the same temperature.
Alternate definition:
where lw is the activity coefficient of water and xw is the mole fraction of water in the aqueous fraction.
Relative humidity:
- The relative humidity of air in equilibrium with a sample is called the Equilibrium Relative Humidity (ERH).
Estimated mold-free shelf life in days at 21° C:
Read more about this topic: Water Activity
Famous quotes containing the word formulae:
“I don’t believe in providence and fate, as a technologist I am used to reckoning with the formulae of probability.”
—Max Frisch (1911–1991)