What is humidity?
Humidity is the presence of water vapour in air (or any other gas).
High humidty means there is a lot of water vapour in the air, low humidity means there is a little.
Air is said to be saturated when it contains the maximum amount of vapour possible at a particular temperature.
At any given time the amount of water vapour in the air is usually less than that required to saturate the air.
Humidity is an interesting and challenging measurement area because:
- water vapour gets everywhere!
- water vapour influences a vast range of physical, chemical and biological processes
- humidity measurement techniques are diverse
- level of air humidity is expressed in many terms, quantities and units
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