Amount of water vapour contained in 1Kg dry air (kg)
The unit is Kg/Kg (DA)
DA means Dry Air
At identical temperature, the vapour partial pressure of the moist air is ％ divided by the vapour partial pressure of the saturated air.
It is used to represent humidity on a daily basis so that people can know in a straight forward sense.
The unit is %RH
RH means Relative Humidity
water vapour partial pressure:
Pressure of water vapour
Moist air containing water vapour to the limit. Contained by the temperature
Amount of water vapour will change. Relative humidity 100%ＲＨ
Degree of saturation:
At a certain temperature, the ratio of moisture content in the saturated air.
Dew point temperature:
Although air can contain a lot of water vapour at higher temperatures, if the temperature of the air is lowered,air soon becomes saturated and on further decrease the water vapour condensed causing dew. The temperature in this case
Moist air diagram:
Since it is very difficult to correlate the humid air which is not saturated (the unsaturated air), by comparing the respective states, diagrams are made.
There are h-x diagram, t-x diagram, t-h diagram etc.,