Application Instructions
25
Hydromette BL Compact RH-T
4.1.3
Relative Air Humidity
The relative air humidity is the relationship between the actual
water vapour content (absolute humidity) and the moisture
saturation. The relative humidity is heavily dependent on the
temperature.
4.1.4
Equilibrium Moisture Content (EMC)
The device is able to display relative humidity, air temperature and
the equilibrium moisture content of wood simultaneously.
This makes it easier for parquet recliners and interior designers to
evaluate whether timber components can be exposed to the
existing climate, or whether damage such as cracking, shrinkage or
swelling is to be feared.
The equilibrium moisture content is the moisture content that wood
will finally reach when it is exposed to a constant climate (i.e.
constant humidity and constant temperature) long enough.
4.1.5
Water Activity (AW)
Water activity is defined as the relative humidity that has to prevail
in the surrounding medium to prevent an exchange of water
between air and material. In practice, it corresponds roughly to the
equilibrium moisture content of a material, but is not given as a
percentage value but as a value between 0 and 1 aw.
The water activity is a measure of the degree of freedom of the free
water (of various types) bound in a material.
