PCE Instruments RH5, User Manual

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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.
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.
Application range
Within the normal application range (normal range) the accuracy of the
device is as indicated. A long-term application beyond the normal application
range (max. range), particularly at an air humidity of more than 80%, can
lead to higher measuring errors (+3% after 60 hours). Back in the normal
application range, the sensor will return to the indicated accuracy
automatically.