Moisture Content Calculation
Calculate the moisture content in products like wood on wet and dry basis.
Moisture content is the amount of water present in a moist sample of a product like wood, soil or similar. Moisture content can be be expressed on wet or dry basis.
Moisture Content on Dry Basis
Moisture content on dry basis is the mass of water to the mass of dry solid:
MCd = mh2o / md (1)
where
MCd = moisture content on dry basis
mh2o = mass of water (kg, lb)
md = mass of dry solid (kg, lb)
Moisture content on dry basis is commonly used in the timber industry. Note that it is common to multiply values with 100%.
Water Content on Wet Basis
Water content on wet basis is the mass of water to the mass of water and mass of solid:
MCw = mh2o / mw
= mh2o / mh2o + md (2)
where
MCw = moisture content on wet basis
mh2o = mass of water (kg, lb)
mw = total mass of moist - or wet - sample - mass of solid and mass of water (kg,lb)
Dry vs. Wet Moisture Calculator
Example - Water Content in Birch on Wet Basis
The density of air-dried seasoned dry Birch is 705 kg/m3 with 20% (0.2) water content. The amount of water per unit volume can be calculated by transforming (2) to
mh2o = mw MCw
= (705 kg/m3) (0.2)
= 141 kg/m3
The amount of solids can be calculated as
md = (705 kg/m3) (1 - 0.2)
= 564 kg/m3
Example - Moisture Content in Birch on Dry Basis
The density of air-dried seasoned dry Birch is 705 kg/m3 with 20% (0.2) moisture content. Equation (1) can be modified to
MCd = mh2o / (m - mh2o) (1b)
where
m = mass water and solid (kg, lb)
This equation can be transformed to
mh2o = MCd m / (1 + MCd ) (1c)
The moisture content per unit volume can be calculated as
mh2o = (0.2) (705 kg/m3) / (1 + (0.2))
= 117.5 kg/m3
The amount of solids can be calculated as
md = m - mh2o
= (705 kg/m3) - (117.5 kg/m3)
= 587.5 kg/m3
Moisture and Water Content Calculator
Related Topics
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Material Properties
Material properties of gases, fluids and solids - densities, specific heats, viscosities and more.
Related Documents
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Air - Drying Force
The drying force of air depends on the air moisture holding capacity and the water surface to air evaporation capacity. -
Air - Humidity Ratio
The mass of water vapor present in moist air - to the mass of dry air. -
Air - Moisture Holding Capacity vs. Temperature
The moisture holding capacity of air increases with temperature. -
Compressed Air - Water Content
Saturation pressure and maximum water content in compressed air. -
Fruits and Vegetables - Optimal Storage Conditions
Optimal temperature and humidity conditions for common fruits and vegetables. -
Soil - Water Content
Water or moisture content in soil. -
Water Content in Food and other Products
Water content before and after drying - in food and other products cork, grain, soap, peat, wood and more. -
Wood - Compressive Strength vs. Moisture Content
Red Spruce, Longleaf Pine and Douglas Fir - moisture content and their compressive strength. -
Wood Species - Moisture Content and Weight
Weight of green and air-dried fire wood.
