Varieties of devices that measure air humidity

To maintain optimal climatic performance in an apartment or production room, more than just temperature control is important. An air humidity meter installed in the room will be especially useful if there are children or residents with respiratory diseases in it. These devices are also useful for warehouses and storerooms.

Determination of air humidity

The device shows how many grams of water are in the air

Recommendations for creating and maintaining an optimal indoor climate usually indicate a relative humidity index. This parameter is determined by devices. They show the content of water vapor in air masses as a percentage of the highest possible value under a given temperature condition.

The absolute value shows how many grams of water there are in a cubic meter of the atmosphere. Determining it in practice is required when comparing the moisture content in hot and colder air (for example, in a bathhouse). In everyday life, it is customary to use a relative value as more understandable. The hotter the air, the higher the maximum achievable moisture vapor content in it. Sanitary standards establish the framework of recommended indicators for premises of a particular purpose.

The principle of operation of instruments for measuring air humidity

Devices for determining air humidity

Devices that allow you to measure the approximate moisture content have been known since the 18th century. The principle of operation of some of them is based on stretching or deformation of membrane elements or fat-free hairs. When the moisture content is stable, the sensitive component should freeze. With the growth of the index, the hair or membrane lengthens.

There are also types of air humidity meters based on other parameters - for example, the change in the electrolytic resistance of some materials or the mass of water absorbed from a certain volume of air.

Modern electronic devices equipped with a thermal 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, while others are inaccurate.

Hair

This is the most common mechanical type meter. It is capable of recording readings in the range from 30 to 80%. The main components of the device are:

  • fat-free horsehair;
  • metal frame;
  • scale with pointer - division corresponds to percentage;
  • calibration screw;
  • a pulley through which the end of the hair is thrown with an attached sinker.

It is not necessary to measure the length of the hair directly when working with the device. Changes in its length with fluctuations in humidity are transmitted by means of a pulley to an arrow-pointer. For more accurate reading of indicators, it is advisable to place the device at the eye level of the person recording the data.

Film

Film hygrometer

This mechanical device is similar in principle to the previous device. It has a built-in film component that tends to stretch when the air humidity rises and shrink when it drops. As a consequence, the position of the center of the film changes, which provokes the movement of the pointer. These devices, as well as hairs, must be checked from time to time with a high-quality psychrometric or other high-precision device. They are often used to work in subzero temperatures.

Weight

These hygrometers measure absolute humidity. They include a complex of U-shaped tubular elements filled with a substance capable of almost complete absorption of moisture contained in air masses. This can be, for example, molten calcium chloride. The procedure is usually carried out as follows: first, the installation is weighed, and then a certain volume of air is passed through it with a piston. By re-measuring the mass, you can calculate the amount of water.

Condensing

Psychrometric hygrometer

Such a device allows you to fix the dew point on a cooled glass or metal mirror surface, which has a built-in temperature sensor. The moment of evaporation or settling of moisture is identified by the scattering of a beam of light. The device is used to measure both relative and absolute values. These devices now use semiconductor components. These include temperature resistors, which are built into mirrors, and coolers, whose work is based on the Peltier effect.

Psychrometric

Psychrometers are called meters containing normal and moistened (for example, by wrapping in a wet cloth) thermometers. Lowering the temperature of the second device allows you to find out how much water is contained in the test gas. To neutralize the increase in local humidity arising from the accumulation of vapors near the wetted thermometer, blowing with a fan is used.

There are the following types of devices:

  1. 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 depends on the air flow rate.
  2. Aspiration models, in which thermometers in a protective nickel frame are blown by the ventilation mechanism at the same speed.
  3. Remote devices. 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. It is best to use distilled water - it provides the greatest measurement accuracy. If this is not possible, the liquid must be boiled.

Electronic

Electronic hygrometer provides the most accurate results

Of all the categories of devices, this type shows the most accurate data. The devices included in it can have different reference data: the electrical conductivity of the atmosphere, the resistance of certain materials, changes in the capacitance of the capacitor elements. There are also models equipped with an optoelectronic unit capable of determining the dew point. Indoor hygrometers are neutral in design to suit most décor options.

Basic rules for choosing instruments for measuring humidity

When choosing a moisture meter for indoor air, the range of indicators that can be fixed using the device and the degree of measurement accuracy are of decisive importance. The reliability of the device and the ability to ensure proper operating conditions are also important.

Principle of operation

Electronic and mechanical models are produced for use in modern apartments. The advantages of the former, in addition to high accuracy, include fast preparation of the result and the ability to integrate several options in one device.Home weather stations can measure temperature, pressure, dew point, date and time. Some of these devices are equipped with a WiFi module. They display information about the weather in a given area. A compact portable hygrometer is also available.

The main plus of mechanical meters is independence from electricity, batteries and other power sources. They are easy to work with and require little calibration change. The simplicity of the design allows you to independently repair the device. The price is not much inferior to the simplest electronic models.

Humidity range

Sauna hygrometer has a wider range of humidity measurement

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 indicators are in the range of 30-70%. In the nursery, in the first year of a baby's life, you need 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 instrument reads the maximum temperature reading of the working area. For example, a device for a bath room or sauna must register heating up to 120 ° C. For such a purpose, it is better to purchase a special hygrometer, sharpened for operation precisely in such conditions.

Measurement accuracy

Some types of premises are kept within a narrow range. For example, in the wine cellar, 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 precision 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 well-defined indicator of the steam content, devices with a minimum value are chosen.

Restoration of optimum moisture levels

To eliminate dryness in the room, it is recommended to buy a humidifier

The content of water vapor in the atmosphere affects the well-being and breathing of people in the room. It is of particular importance in diseases of the bronchi, lungs and ENT organs. If the humidity level in the room has been measured and the value is outside the recommended range, appropriate measures must be taken.

If the air is constantly dry, you can do the following:

  1. Purchase a humidifier. Climatic technology will allow you to monitor the indicators of the atmosphere and maintain them within the specified limits. Modern devices have a flexible and variable system of settings and are equipped with additional options, for example, ionization and filtration of dust and pollen particles (which is important for allergy sufferers).
  2. Ventilate the room more often. This method is relevant for most of the year, but in summer in dry climates it can only make matters worse. In addition, when the windows are opened, allergenic agents, microorganisms, and harmful gases from the street get into the home. But keeping them closed is also impractical - this leads to the accumulation of excess carbon dioxide. It is necessary to organize ventilation of the dwelling. To do this, you can purchase a breather that heats and filters the outside air and supplies it to the room.
  3. Do not forget about timely wet cleaning.
  4. 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.
  5. Setting up a home aquarium will help improve climatic conditions. In this case, one should not forget about caring for the fish and maintaining hygiene.

If there is too much water vapor in the air, do not hang washed clothes in the bathroom or living rooms. Better to take things out to the balcony. After taking a bath or shower, the bathroom is ventilated. If the house has a breather, it should be turned on for at least 30 minutes.You can also purchase an appliance with a fan and an evaporator to help remove excess moisture in the atmosphere.

Dry air is detrimental to plants. When placed in unsuitable climatic conditions, they wither and become sick. First of all, the process is noticed by the leaves, which begin to dry out and fall off. Cultures, whose homeland are tropical and subtropical areas, are especially in need of moisture.

Modern mechanical and electronic models of hygrometers are suitable for domestic use. Some types of premises require highly accurate measurements with minimal error.

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