Environmental parameters often change, depending on external factors (air temperature, weather conditions). The microclimate in the room immediately becomes different. This is felt more strongly if there are errors in the operation of the heating system, the air circulation in the house is disrupted, or micro-cracks appear in the window units.
This effect is enhanced when flowers are regularly watered, laundry is dried in the room, etc. To influence air humidity, you need to understand how much it changes. To do this, measure this parameter using a hygrometer.
What is air humidity
The name of the parameter encrypts its value.
Humidity is an indicator that determines the water content in different environments.
If you need to find out how much moisture there may be in the air, you should focus on the normal variant - values in the range of 30-60%. But this value is constantly changing.
Values entered:
- absolute;
- relative.
In the first case, the water content in the air with a volume of 1 m3 is determined. This indicator is also called the density of water vapor in the air.
The second option is the ratio of the mass fraction of steam to the maximum for given parameters. Units - %.
Instruments for measuring air humidity
Use a hygrometer. Its main function is to determine the moisture content in the air.
There are several types:
- hairline;
- film;
- conductometric;
- weight and condensation;
- ceramic;
- psychometric;
- electronic.
Devices are distinguished by their mechanism of action and efficiency.
The electronic type of the device allows you to get results quickly. Mechanical analogues are reliable, but will require more time for measurements.
Hair hygrometer
The device is designed to determine changes in moisture content within the range of 30-80%. Hair (hair) hygrometer is a mechanical type device. It is designed quite simply.
Structural elements: a metal frame, human hair, on which a small weight is attached, and also a pulley, an arrow, and a scale with divisions. The operating principle of the device is based on changes in hair length under the influence of environmental parameters.
Film hygrometer
The device can withstand more significant mechanical loads than its hair counterpart. The design includes an organic film. The device measures air humidity according to a similar principle to the previously discussed option: the arrow moves when the size of the membrane increases/decreases.
Weight and condensation hygrometers
The principle of operation is based on increasing the weight of the substance that absorbs moisture. The device measures the absolute humidity in a room. The design provides several connected tubes filled with calcium chloride.
Such a hygrometer determines the change in indoor air humidity by determining the difference between the weight before and after the hygroscopic substance absorbs moisture from the environment. In this case, the most accurate result is obtained.
Condensation hygrometer is a device for measuring relative air humidity. For this purpose, the principle of determining the temperature difference is used. The mechanism of action of the hygrometer: under the influence of a beam of light that falls on a special mirror, condensation appears or ice crystals form. Relative humidity is determined by the difference in temperature before and after condensation occurs.
Psychrometric hygrometer
The operating principle of the device is also based on measuring the ambient temperature. Only the design of the psychometric hygrometer provides for 2 thermometers (dry, wet), and not 1, as in the previously discussed device.
As moisture evaporates, environmental parameters change. Air humidity is determined using data: determining the rate of condensate evaporation, the temperature difference between two thermometers.
Ceramic hygrometer
During operation of the device, the electrical resistance of a mass of ceramic material and metal particles is measured. Materials used: kaolin, clay, silicon. The device works best if the mass includes metal oxides.
Electronic hygrometer (digital)
When choosing a way to measure the humidity in a room as accurately as possible, you should consider the electronic version of the device. The principle of its operation is based on changing the resistance of lithium chloride, which covers the plate inside the hygrometer. A built-in thermometer is provided for increased accuracy.
Hair hygrometer
From the name of this device you can guess that there is hair somewhere in its device. And, indeed, the action of the hair hygrometer (Figure 3) is based on one interesting property of human hair. The fact is that as the relative humidity of the air increases, the hair lengthens.
Figure 3. Hair hygrometer
The scale of this device already shows the relative humidity values. When relative humidity increases, hair lengthens, and when relative humidity decreases, it shortens. In this case, the arrow moves along the scale, indicating the value of relative air humidity.
Alternative measurement methods
To determine changes in air parameters, improvised means are used. They do not provide accurate data. However, if there is a suspicion that the air humidity does not meet the standards, there will be reasons to purchase a special device.
Alternative methods:
- Glass of water. It is cooled (to +5°C), then left in the room. If condensation appears and flows onto the table, high air humidity is suspected. When the walls dry out quickly, the humidity is considered too low.
- Tabular method based on temperature difference. A mercury thermometer is used. To obtain the necessary data, it is recommended to measure the air temperature in normal conditions and in a humid environment (the thermometer is wrapped in a damp towel).
How to choose an air humidity meter
There are a number of parameters that you pay attention to before purchasing:
- hygrometer type;
- accuracy (the best option is an electronic device);
- device capabilities: take into account the range of measured humidity values;
- operating conditions (pay attention to the permissible air temperature);
- the ability to move the device from place to place.
Modern models of electronic devices perform different tasks, for example, they are also used as an alarm clock, barometer, some of them have a Wi-Fi function.
Air dryers
This device is designed to effectively absorb excess moisture. During the treatment process, air passes through a special evaporating membrane, which turns moisture into condensate. Drops of water are collected inside the device in a special container. The air is reheated and comes out, clean but devoid of moisture.
Important! When purchasing such a unit, do not forget to pay attention to the performance of the device and the maximum permissible volume of water that the dehumidifier can process per day. Household dehumidifiers are capable of drying from 12 to 300 liters of water in 24 hours. They are:
They are:
They are:
Household dehumidifiers are capable of drying from 12 to 300 liters of water in 24 hours. They are:
- Portable. This model is lightweight and portable and can be placed in any room.
- Stationary. The dehumidifier is mounted on the wall, so it cannot be transported from one room to another.
Important! Such devices can even be used in refrigerated rooms. This will at least promote the formation of frost. When the tank is completely filled with water, due to untimely emptying of the tank, the dehumidifier automatically turns off
When the tank is completely filled with water, due to untimely emptying of the tank, the dehumidifier automatically turns off.
Humidity range and heating threshold
According to GOST, the norm in winter is considered to be relative humidity of 30-45%, and in summer – from 30 to 60%. When choosing a hygrometer for indoor use, consider the range of values:
- 20-80% in the bedroom;
- bathroom – 100%, because the indicators here are constantly increasing;
- balcony, pantry, kitchen - from 10 to 90%; in these rooms the humidity also often increases.
The hygrometer can be used when the air temperature rises to +120°C, which allows it to be used in a sauna or bathhouse.
How to maintain relative humidity in your home
Indoor environmental conditions are constantly changing. If at a given moment in time there is a need to influence the humidity, and it is not possible to wait for the value to change naturally, it is recommended to resort to improvised methods.
If the humidity is low
Effective methods:
- ventilation, which normalizes the circulation of air flows;
- wet cleaning;
- There are several containers of water around the apartment.
A humidifier, air conditioner, and thermostat are used in the room.
If the humidity is high
Eliminate any sources of moisture:
- clothes to dry are hung on the balcony, not in the room;
- adjust the windows to increase the flow of air flow;
- include compact heaters;
- Air dehumidifiers are used.
Restoring optimal humidity 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 for diseases of the bronchi, lungs and ENT organs. If the humidity level in a room is 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:
- Buy a humidifier. Climate technology will allow you to monitor atmospheric indicators and maintain them within 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).
- Ventilate the room more often. For most of the year this method is relevant, but in the summer in regions with a dry climate it can only worsen the situation. In addition, when opening windows, allergenic agents, microorganisms, and harmful gases from the street enter 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 home. To do this, you can purchase a breather that heats and filters street air and supplies 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 near heating radiators - at elevated temperatures, evaporation occurs faster. You can place the container on the windowsill.
- Installing a home aquarium will help improve climatic conditions. At the same time, we should not forget about caring for the fish and maintaining hygiene.
The first signs of microclimate change
You can notice an increase or decrease in indoor air humidity based on a number of signs. If the indicator is increased:
- laundry takes a long time to dry;
- Condensation appears on the windows;
- black fungus appears on surfaces.
If the moisture content is reduced (less than 30%), you can notice this due to the following signs:
- family members develop a dry cough, and only at home;
- the skin and mucous membranes are dry;
- nosebleeds often occur;
- itching increases due to a constant feeling of dryness;
- the skin is peeling.
Humidity in the environment
Air humidity is important both in nature and in human life. Initially, our well-being often depends on this indicator. After all, the intensity of moisture evaporation from our skin is determined by air humidity. Low humidity can lead to dry mucous membranes, problems with skin and hair, and very high humidity can lead to a deterioration in general physical condition.
Air humidity affects the heat exchange of many organisms with the environment, the life of animals and plants. When people grow plants in greenhouses or conservatories, they need to know and control the air humidity. In this way, the necessary regime for their growth and vital activity is maintained.
The value of air humidity plays a big role in meteorologists for weather forecasts. When operating various equipment, it is important to take into account humidity - at high levels, corrosion occurs faster. When storing important works of art and books, keep an eye on humidity as well.
conclusions
When signs of changes in relative humidity become noticeable, you should try to normalize the values of this parameter. If laundry takes a long time to dry, condensation appears on the windows, or family members cough, then it is first recommended to measure the air humidity in the room.
Hygrometers are used for this. They are presented in different types: electric, ceramic, mechanical, etc.
In order to increase/decrease the moisture content in the air, they resort to improvised means or connect special equipment (humidifiers, dehumidifiers, air conditioning).
Types of hygrometers and features
There are different types of instruments for measuring air humidity. Some of them demonstrate high accuracy of readings, others allow for error.
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 include:
- defatted horsehair;
- metal frame;
- scale with pointer - division corresponds to percentage;
- calibration screw;
- a pulley through which the end of the hair with an attached sinker is thrown.
There is no need to measure hair length directly when working with the device. Changes in its length due to fluctuations in humidity are transmitted via a pulley to the pointer arrow. For more accurate reading of indicators, it is advisable to place the device at eye level of the person recording the data.
Film
This mechanical device is similar in principle to the previous device. A film component is built into it, which tends to stretch when air humidity increases and shrink when it decreases. As a result, the position of the center of the film changes, which causes the pointer to move. These devices, as well as hair devices, 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 tubular elements shaped like the letter U and filled with a substance capable of almost complete absorption of moisture contained in air masses. This could 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 measuring the mass again, you can calculate the amount of water.
Condensation
This device allows you to record the dew point on a cooled glass or metal mirror surface, which has a built-in temperature sensor. The moment of evaporation or deposition of moisture is identified by the scattering of the light beam. The device is used to measure both relative and absolute values. Nowadays, such devices use semiconductor components. This includes temperature resistors that are built into mirrors, and coolers whose operation is based on the Peltier effect.
Psychrometric
Psychrometers are meters that contain regular and moistened (for example, by wrapping in a wet cloth) thermometers. Reducing the temperature of the second device allows you to find out how much water is contained in the gas under study. To level out the increase in local humidity that occurs due to the accumulation of vapors near the wetted thermometer, blowing with a fan is used.
The following types of devices exist:
- Psychrometers for weather stations, mounted on a tripod. They are installed directly into the booth. The disadvantage of this scheme is that the data from a “wet” thermometer depends on the air flow rate.
- Aspiration models, in which thermometers in a protective nickel frame are blown by a ventilation mechanism at the same speed.
- 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 using 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 shows the most accurate results
