The moisture content of all materials tries to reach an equilibrium with the relative humidity in ambient air

物质中的水份总是试图与环境的相对湿度达到平衡

At equilibrium the relative humidity of the material is called equilibrium relative humidity ERH

物质中的湿度达到平衡后称为平衡相对湿度

Equilibrium relative humidity divided by 100

平衡相对湿度除以 100 A w = ERH / 100

Application

应用 : moisture in oil 油中微量水份