(i) Dry bulb temperature:
It is the temperature recorded by the thermometer which is not affected by moisture.
(ii) Dew point temperature:
It is the temperature of air at which water vapour in air starts condensing.
(iii) Humidity ratio or specific humidity:
It is the mass in kg. of water Vapour contained in the air vapour mixture per kg. of dry air.
It is the ratio of the mass of water vapour to the mass of dry air in certain volume of mixture.
(iv) Wet bulb temperature:
Bulb is covered with muslin wick wetted with water is moved past unsaturated air at velocity of 300m/minute. The temperature reading obtained is wet bulb temperature.
(v) Absolute humidity:
Actual quantity of water in a given amount of air.
(vi) Load on air conditioning system:
Amount of heat that must be removed from air of a given space.
Used for distributing air in the building at different places.