Wood equilibrium moisture content
Wood equilibrium moisture
Wood hygroscopicityWood moisture content increases or decreases according to the temperature and the humidity of surrounding air.
Placed in a different atmosphere than from where it has previously been, wood will tend to become more humid or drier. After some time, wood reaches equilibrium in relation to the temperature and the humidity and thus cannot not be either more humid or drier, unless one of these factors varies.
When wood is stabilized, it has reached hygroscopic equilibrium or moisture equilibrium.
Measurement of equilibrium moisture contentThe equilibrium moisture content of wood (EMC) has an impact on the mechanical properties and the thermal conductivity of the material, the energy content of the fuel as well as its decay resistance.
Any wood business person should measure equilibrium moisture content of wood to valorise and guarantee the quality of supply thanks to the optimisation of storage and process conditions.
Green wood moistureGreen wood refers to trees that still have sap or to wood that has not lost its natural moisture after being cut (the log water content is 50%-100% on wet wood).
Once free water has evaporated, bound water is still present and its variation is at the origin of dimensional changes of wood.
With its hammer probe, this moisture meter allows to measure water content and temperature of billets, logs or blocks, even freshly cut.
This humidity tester is designed to measure moisture in piles of paper and line paper thanks to its sword sensor 30cm long. This air humidity meter is also ideal to monitor the climate of printing rooms and paper depot and allow to log measurements.
Fibre saturation point
When free water has evaporated from the wood cell lumina, water bound to wood cell walls remains.
The corresponding equilibrium moisture content is approximately 30% in most wood species and is called the "fibre saturation point" or FSP.