Often from TV screens or from radio speakers we hear about air pressure and humidity. But few people know what their indicators depend on and how these or those values affect the human body.
Humidity is a characteristic of the saturation of the atmosphere with water vapor. In different parts of the world, its indicators can differ dramatically. In nature, there is no air without water vapor. There is no place on Earth where zero relative humidity occurs. So, in the desert, sugar is 25 percent, in the Brazilian jungle - 90.
Relative humidity is the ratio of the amount of moisture in the atmosphere compared to the maximum possible at a given temperature or the degree of its saturation with water. That is, this indicator indicates how much more vapor is needed for the condensation process to begin. Relative humidity is one of the most important characteristics of the state of the environment.
The absolute indicator is measured in 1 g/m3 or in millimeters of mercury. At the equator it is 20-30 g/m3, while in the Arctic and Antarctic it is 0.1-1.
Humidity for humans
Humidity, the norm of which is from 40 to 60 percent for residential premises, is clearly felt by a person. It reaches its highest value in summer during rainy weather: then its indicator is at around 80-90%.
In winter, the situation is completely opposite in the apartments of Russians. Due to heating, relative humidity drops as much as 15 percent. This is due to the increase in temperature from heaters, which, in turn, causes active evaporation of moisture from the surface of the body and furniture.
Humidity is often an underestimated factor. When this indicator tends to minimum or maximum values, a person's well-being worsens: fatigue increases, memory properties and concentration decrease. In order to stay in physical and mental tone, it is necessary to ensure the optimal humidity of the rooms in which people live and work. There are special air conditioning systems for this.
Evaporation of moisture from the skin also depends on humidity, which, in turn, determines the temperature of the human body and the state of his body. A favorable indicator for vital activity is 40-60%. It is this humidity that contributes to good he alth. This indicator is artificially maintained in the compartments of spacecraft.
Means and methods of determination
To determine the saturation of air with watercouples use special instruments: psychrometers and hydrometers. August's psychrometer is a bar with two thermometers: wet and dry.
The first is wrapped in a cloth soaked in water, which, when evaporated, cools its body. Based on the readings of these thermometers, the tables determine the relative humidity of the air. There are many different hydrometers, their work can be based on weight, film, electric or hair, as well as a number of other principles of operation. In recent years, integrated measurement sensors have gained popularity. Hydrostats are used to check the accuracy of measuring instruments.
