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What is a dew point?


The dew point temperature is the temperature at which the air can no longer "hold" all of the water vapor which is mixed with it, and some of the water vapor must condense into liquid water. For example, if we cool the air around us down to 10 degree and some water vapor starts to condense into liquid water, that is "this air’s dew point temperature is 10 degree".
In industrial and semiconductor manufacturers, sometimes they have to deal with gas whose dew points are as low as -80 degree, for example. It means that the level of moisture in the gas or air is so low that when the temperature is at as low as -80 degree, condensation starts to occur. Many people might be more familiar with relative humidity as humidity and moisture measurement unit, but just like the word “relative” itself explains, it indicates how much influence the temperature gives to the humidity level. On the other hand, dew point is not influenced by temperature and it shows absolute value of the amount of moisture in gas.
To measure dew point, you need to have a sampling system with the most suitable instrument to your needs which is connected to plumbing directly.