The humidity shows what amount of vapors of water contains in air. An important ecological indicator of the environment is relative humidity. If it accepts too low or too high values, the person quickly is tired, his perception, memory and health worsens.
Instruction
1. The humidity is absolute and relative. The absolute humidity of f shows real amount of water vapor on the weight which is in one cubic meter of air. To find absolute humidity of air, divide the mass of steam to the total amount of damp air. Units of measure – gram on cubic meter, g/m³.
2. There is a concept of the maximum absolute humidity at the fixed temperature. The fact is that density of water vapor cannot increase indefinitely, at some point there comes thermodynamic balance. This such condition of a system at which macroscopic parameters, such as temperature, volume, pressure, entropy, are constant in time. These sizes fluctuate near the average values if the system is most isolated from influences of the external environment.
3. So, at approach of thermodynamic balance between steam and air say that air is saturated with steam. The humidity of the air saturated with steam also is maximum. It is called also saturation border. It is measured in g/m³ too. It is possible to designate it for F.
4. To determine relative air humidity, find the relation of absolute humidity to maximum: φ=f/F. The same result will be received if to divide vapor pressure into pressure of saturated steam. Relative humidity – dimensionless size, can register as a percentage.
5. Air saturation steam depends on temperature. That temperature at which this amount of water vapor sates air is called a dew point. At achievement of this temperature, condensate appears, or, in other words, dew drops out. In general, the higher temperature, the more than couple it is necessary for air saturation.