Relative humidity is measurement of amount of water vapor in mix of air and water vapor. It is usually defined as the partial pressure of water vapor in the mix given as percent of damp vapor pressure.
Instruction
1. Relative air humidity changes not only rather absolute humidity (moisture content), but also concerning temperature and pressure on which vapor pressure depends. Relative humidity oftenof it is used instead of absolute humidity in situations where the rate of water evaporation is important as change in damp vapor pressure is taken into account.
2. Relative humidity is also defined as the relation of partial pressure of water vapor in mix to the damp vapor pressure of water at a certain temperature
3. Relative humidity usually is expressed as percent. There are several empirical correlations which can be used to estimate the damp vapor pressure as function of temperature. Antuann's equation is the least difficult of these formulas, having only three parameters (A, B, and C).
4. It is possible to define by the equations that the maximum relative mistake when determining humidity makes less than 0.20%.
5. The humidity is a concept of physical properties of water, and is not connected with a concept of the air containing water. Therefore at calculation of humidity it is necessary to consider properties of water and to carry out, the related calculations of humidity.