What is the concept of dew point

Dew point refers to the temperature at which the water in the gas changes from unsaturated steam to saturated steam. When the unsaturated steam changes to saturated steam, fine dew drops appear. The temperature at which dew drops appear is called "dew point", which indicates the water content in the gas. The lower the dew point, the less the water content in the gas, and the drier the gas. Dew point is related to pressure, so it can be divided into atmospheric dew point (atmospheric dew point) and dew point under pressure. The atmospheric pressure dew point refers to the condensation temperature of water under atmospheric pressure, and the dew point under pressure refers to the condensation temperature of water under this pressure. There is a conversion relationship between the two (see the conversion table). If the pressure dew point is 5 ℃ at 0.7MPa, the corresponding atmospheric pressure (0.101MPa) dew point is -20 ℃. In the gas industry, unless otherwise specified, the dew point refers to atmospheric pressure dew point.