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Description of definitions
Relative air humidity: indicates the relation between the current water
vapour pressure and the maximal possible water vapour pressure (called
saturation vapour pressure)
The relative humidity shows the degree the air is saturated with water
vapour. For example:
50% relative humidity indicates that at the current temperature and the
current pressure the air is saturated with water vapour for half of its value,
100 % relative humidity means that the air is totally saturated. When the air
has more than 100 % of relative humidity, the excessive moisture would
condense or form fog.
Absolute humidity: shows the contained amount of water in gramme per
cubic metre of air. The absolute humidity is a direct degree for the amount of
water vapour contained in a certain air volume. It shows how much moisture
can maximally condense or how much water has to be evaporated to receive
a certain desired air humidity.
Dew point temperature:The dew point indicates the temperature that the
not completely saturated air has to reach in order to be completely saturated
with water vapour. If the room with the current relative humidity is cooled
down to the dew point temperature, the water vapour begins to condense.
EMC wood: shows the equilibrium moisture content of wood (for timber
stored under these conditions) in % moisture content of wood and the
temperature in the selected unit (°C or °F).
EMC POM: shows the equilibrium moisture content of POM granulate (for
granulate stored under these conditions) in % moisture content and the
temperature in the selected unit (°C or °F).
aw value: indicates the freely available water in a material. It is defined as
the partial vapour pressure of water in a substance divided by the standard
state partial vapour pressure of water at a certain temperature.
