To maintain optimal climatic indicators in an apartment or industrial premises, not only temperature control is important. A device for measuring air humidity installed in a room will be especially useful if there are children or residents with respiratory diseases in it. These devices are useful for storage and storage rooms.
Determination of air humidity
The recommendations for creating and maintaining an optimal indoor climate usually indicate a relative humidity indicator. This parameter is determined by the devices. They show the water vapor content in air masses as a percentage of the highest possible value under given temperature conditions.
The absolute value shows how many grams of water are in a cubic meter of atmosphere. It is required to determine it in practice in the case of comparing the moisture content in hot and colder air (for example, in a bath room). In everyday life, it is customary to use the relative value as more understandable. The hotter the air, the greater the maximum attainable figure for the content of wet vapor in it. Sanitary standards set the framework of recommended indicators for premises for one purpose or another.
The principle of operation of instruments for measuring air humidity
Devices that allow you to measure the approximate moisture content, known since the XVIII century. The principle of operation of some of them is based on stretching or deformation of the membrane elements or fat-free hairs. When the moisture content is stable, the sensitive component should freeze. With an increase in the hair index or the membrane lengthens.
There are also types of air humidity meters based on other parameters - for example, a change in the electrolytic resistance of some materials or a mass of water absorbed from a certain volume of air.
Modern electronic devices equipped with a temperature sensor rely on its readings and data on the vapor content. Some of them inform the user about the temperature, which eliminates the need to purchase a thermometer.
Varieties of hygrometers and features
There are different types of instruments for measuring air humidity. Some of them demonstrate high accuracy of readings, others admit an error.
Hair
This is the most common mechanical type meter. He is able to record readings in the range from 30 to 80%. The main components of the device include:
- fat free horse hair;
- metal frame;
- scale with a pointer - division corresponds to a percentage;
- calibration screw;
- a pulley through which the end of the hair is thrown with an attached sinker.
It is not necessary to directly measure the length of the hair when working with the device. Changes in its length due to humidity fluctuations are transmitted via a pulley to the arrow. For a more accurate reading of indicators, it is advisable to place the device at eye level of the person fixing the data.
Film
This mechanical device is similar in principle to the previous device. A film component is mounted in it, which tends to stretch with increasing air humidity and shrink when lowering. As a result, the position of the center of the film changes, which provokes the movement of the pointer.These devices, as well as hair, from time to time must be checked with a quality psychrometric or other high-precision device. Often they are used to work in freezing temperatures.
Weight
These hygrometers allow you to measure absolute humidity. They include a complex of tubular elements in the form of the letters U and filled with a substance capable of almost complete absorption of the moisture contained in the air masses. This may be, for example, molten calcium chloride. The procedure is usually carried out as follows: first, the installation is weighed, and then a certain amount of air is passed through it with a piston. By re-measuring the mass, you can calculate the amount of water.
Condensation
Such a device allows you to fix the dew point on a cooled glass or metal mirror surface, in which a temperature sensor is built. The moment of evaporation or settling of moisture is identified by the scattering of a ray of light. The device is used to measure both relative and absolute values. Now in such devices components from semiconductors are used. These include temperature resistors that are built into mirrors, and coolers whose operation is based on the Peltier effect.
Psychrometric
Psychometers are called gauges that contain normal and moist (for example, by wrapping in a wet rag) thermometers. Lowering the temperature of the second device allows you to find out how much water is contained in the test gas. In order to offset the increase in local humidity resulting from the accumulation of vapors in the vicinity of a wet thermometer, fan blowing is used.
The following types of appliances are available:
- Psychrometers for weather stations mounted on a tripod. They are installed directly in the booth. The disadvantage of this scheme is that the data of the "wet" thermometer depend on the air flow rate.
- Aspiration models in which thermometers in a protective frame made of nickel are blown by a ventilation mechanism at the same speed.
- Remote appliances. Instead of thermometers, they use silicon sensors. As with other types of devices, one of the elements is wetted.
Calculations of indicators are made according to psychrometric tables and special formulas. Distilled water is best used - it provides the most accurate measurements. In the absence of such a possibility, the liquid must be boiled.
Electronic
Of all the categories of devices, this variety shows the most accurate data. The instruments included in it can have different reference data: the electrical conductivity of the atmosphere, the resistance of certain materials, changes in the capacitance of capacitor elements. There are also models equipped with an optoelectronic unit capable of determining the dew point. Indoor hygrometers have a neutral design, suitable for most interior options.
Basic rules for choosing humidity measuring instruments
When choosing a room air moisture meter, the range of indicators that can be fixed with the device and the degree of measurement accuracy are of decisive importance. Reliability of the device and the ability to ensure proper operating conditions are also important.
Principle of operation
For use in modern apartments, electronic and mechanical models are available. The advantages of the former, in addition to high accuracy, include quick preparation of the result and the ability to integrate several options in one device. Home weather stations can measure temperature, pressure, dew point, display date and time. Some of these devices are equipped with a WiFi module. They display weather information for the area. A compact portable hygrometer is also available.
The main plus of mechanical meters is independence from electricity, batteries and other power sources. It is easy to work with them; they need little calibration changes. Simplicity of design allows you to repair the device yourself. The price is not much inferior to the simplest electronic models.
Humidity range
The scope of the recorded range is determined by the purpose of the room in which the moisture meter will be installed. For living rooms, acceptable rates are in the range of 30-70%. In the nursery in the first year of life, the baby needs to maintain dry air. The requirements for the kitchen and balcony rooms are minimal - the main thing is that the indicator does not approach extremes (more than 90% or less than 10).
It is important that the device reads the maximum temperature value of the working area. For example, a device for a bathhouse or sauna should register heating up to 120 ° C. For this purpose, it is better to purchase a special hygrometer, sharpened for operation in such conditions.
Measurement accuracy
Some types of rooms are kept in a narrow range. For example, in the cellar where wines are stored, the content of water vapor in the atmosphere should be 65-75%, in the library - 50-60%. For such premises, it is advisable to purchase accurate instruments. Modern psychrometers and electronic meters have error rates from 1 to 10%. For storage chambers and other places where it is necessary to maintain a clearly defined indicator of the vapor content, devices with a minimum value are chosen.
Restoring optimal moisture levels
The content of water vapor in the atmosphere affects the well-being and breathing of people in the room. It has special significance in diseases of the bronchi, lungs, and ENT organs. If the humidity level was measured in a room and the value turned out to be beyond the recommended range, relevant measures should be taken.
With constant dry air, you can do the following:
- Purchase a humidifier. Climatic equipment will allow monitoring atmospheric parameters and maintaining them within the given framework. Modern devices have a flexible and variable settings system and are equipped with additional options, for example, ionization and filtering of dust and pollen particles (which is important for allergy sufferers).
- Ventilate the room more often. Most of the year this method is relevant, but in the summertime in regions with a dry climate it can only aggravate the situation. In addition, when opening windows, allergenic agents, microorganisms, harmful gases from the street get into the house. But keeping them closed is also impractical - this leads to the accumulation of excess carbon dioxide. It is necessary to organize ventilation of the home. To do this, you can buy a breather that heats and filters the street air and delivers it to the room.
- Do not forget about timely wet cleaning.
- Place bowls or basins filled with water in your home. It is better to do this next to heating batteries - at elevated temperatures, evaporation occurs faster. You can put the container on the windowsill.
- Improving climatic conditions will help to install a home aquarium. At the same time, one should not forget about caring for fish and maintaining hygiene.
If there is too much water vapor in the air, do not hang the washed clothes in the bathroom or living rooms. Better to take things to the balcony. Having taken a bath or shower, the bathroom is ventilated. If the house has a breather, it is turned on for at least 30 minutes. You can also purchase a device with a fan and an evaporator, which helps to remove excess moisture in the atmosphere.
Dry air is harmful to plants. When placed in unsuitable climatic conditions, they fade and become sick.First of all, the process is noticed by leaves that begin to dry and fall off. Particularly in need of moisture culture, whose homeland is tropical and subtropical areas.
For domestic use, modern mechanical and electronic models of hygrometers are suitable. Some types of rooms require high-precision measurements with minimal error.
