The moisture content of all materials tries to reach an equilibrium with the relative humidity in ambient air
物質中的水份總是試圖與環境的相對濕度達到平衡
At equilibrium the relative humidity of the material is called equilibrium relative humidity ERH
物質中的濕度達到平衡后稱為平衡相對濕度
Equilibrium relative humidity divided by 100
平衡相對濕度除以 100 A w = ERH / 100
Application
應用 : moisture in oil 油中微量水份