Moisture Content Dry Basis

The dry basis measures how much water there is in a solid, expressed as the weight of water as a percentage of the completely dry solid. Dry basis moisture is most commonly used for measuring moisture changes in solid wood products. When measuring the moisture content of the wood on a dry basis, the weight of the wood does not include any free water. It is the weight of the wood after it is oven-dried. When wood loses or gains moisture, the change in the dry basis moisture is linearly related to the weight loss or gain. In simpler terms, in dry basis moisture measurement, the weight of the wood is constant, and the increase or decrease in weight is directly related to the amount of water the wood contains. Moisture content measured on a dry basis can exceed 100%.

Formula

Dry Basis Moisture Content:
MCdry% = 100 x (Wet Weight - Dry Weight) / Dry Weight

The weight of water as a percentage of the weight of the oven dried wood.

MCdry % = 100*(initial weight-oven dry weight)/oven dry weight

Convert dry basis MC% to wet basis MC%

MCcwet% = MCdry/(100 + MCdry)*100

dry weight  = 100 * green weight /(MC dry + 100)

Green weight = dry weight *(1 + MCdry / 100)