Instruments for measuring air humidity: operating principle, types, advantages and disadvantages -

A comfortable stay in an apartment is possible after ensuring a comfortable microclimate suitable for residential premises. The climatic conditions in the room depend on the temperature and humidity of the air, so these indicators must be carefully monitored using special devices.

Thus, a thermometer is used to determine the temperature in a room, and a device for measuring air humidity is called a hygrometer. The principle of operation of a thermometer is familiar to everyone, but not everyone knows how a moisture meter works and how to choose the appropriate option.

Let's look together at the existing types of these devices and the features of their operation in this material. Let's also talk about the rules for choosing a suitable hygrometer.

Why do you need to measure air humidity?

Both excessively dry and excessively humid air can lead to incorrect operation of various devices and equipment and cause health problems. There are optimal humidity parameters for the growth of plants and animals, as well as fermentation processes, which play an important role in food production.

High humidity can cause mold, mildew, and damage to furniture, things and food in the room. Excessive dryness causes a lot of dermatological problems, often causes allergies and causes asthma in a person.

Air is considered too dry when its moisture vapor content is less than 40%, and excessively humid when it contains more than 80%.

Scope of application of professional hygrometers

Portable and stationary humidity measuring instruments are used primarily in the oil and gas and chemical industries. However, the scope of their use is not limited to this. A hygrometer may be needed wherever you are supposed to work with non-aggressive gas mixtures and you need to monitor their condition. Thanks to this, equipment for measuring the percentage of moisture in the air is used at nuclear power plants, in the production of microelectronics, and in the energy sector. They are also used to control the drying process of natural gas.

Professional hygrometers are used to solve a wide range of problems related to the organization of various production processes. In particular, they become indispensable if necessary:

provide a given level of humidity in the room, for example, for storing products under certain conditions;
assess the humidity in the production area for labor protection purposes;
ensure the normal functioning of electrical equipment for various purposes;
provide the level of humidity required for the implementation of a specific production process.

Instruments for measuring air humidity: types, operating principle

Modern manufacturers produce devices of various types and types. The oldest measuring device is the moisture meter, invented by Leonardo da Vinci in 1400. Now it is practically not used.

Modern moisture meters are called hygrometers

It was a pharmacy scale, on one bowl of which a piece of wax was placed, and on the other the same amount of some porous material. The disadvantage of the device is that it can only be used to control fluctuations in air humidity.

Expert opinion

Chebatkov Maxim Pavlovich

Specialist in household appliances and their repair

Modern moisture meters are called hygrometers. These are more accurate measuring devices. Manufacturers produce a wide range of these products, which have different operating principles. All of them serve to measure relative air humidity and have varying degrees of error.

Hygrometers are distinguished:

Hairy . Their operating principle is based on changing the length of human hair, which is the main element of the device. In dry rooms, hair shortens, and in humid rooms it lengthens. These fluctuations in hair length are displayed on the device scale as an indicator of the percentage of moisture vapor in the air.
Psychometric . Their design is considered the simplest. It consists of two mercury thermometers. One of them is dry, and the second is wet. The humidity indicator is determined from the table from the difference in the readings of the thermometers of the device. The work of the psychometer is based on the principle of evaporation and absorption of water. When liquid evaporates from the wetted surface of one of the thermometers, energy loss occurs and, as a result, temperature drops. The reverse process causes an increase in air humidity in the room.

Weighing . The device consists of a pump and tubes filled with a hygroscopic composition that can absorb air. Using a pump, air is pumped into the device, the volume of which and the weight of the structure determine the relative humidity of the air.
Mechanical (ceramic) . The operating principle of the device is based on measuring the electrical resistance of the device filler. It changes with fluctuations in relative air humidity. The filler is a ceramic mass consisting of oxides of kaolin, silicon and clay.
Electronic . The most accurate device. The operating principle is based on changing the resistance of lithium chloride, which is applied to a special glass plate.
Condensation . The main element of the device is a mirror, the temperature of which changes along with fluctuations in air humidity.

Instrument measurement data can be displayed on displays in numerical format or on a dial with an arrow.

What is humidity and how does it affect people?

Air humidity is the amount of evaporated microscopic water particles it contains. Usually the parameter is expressed as a percentage.

Although a person can live in very dry or very humid climates, the optimal level is humidity between 45% and 60%.

High humidity

Increased moisture content in the air (from 70-80%) leads to the following adverse consequences:

Violation of the body's thermoregulation . The body quickly overheats. This is due to the fact that sweat hardly evaporates from the surface of the skin and cannot effectively cool it.
Development of pathogenic bacteria and fungi . Both protozoa and microscopic fungi begin to actively develop in conditions of high humidity. Ultimately, this can lead to various respiratory diseases.
Difficulty breathing . Since the percentage of water in the atmosphere in the described case is high, the proportion of oxygen contained in it decreases due to this. This leads to the fact that, while inhaling the usual volume of air, the human body receives slightly less oxygen. There is a feeling of difficulty breathing.

Reduced

Dry air is also harmful and can lead to the following negative consequences:

Skin problems . The epidermis, like the rest of the body, consists of 70% water. He also receives it from the atmosphere. However, if there is not enough moisture in the surrounding air, a deficiency occurs in the skin. The most harmless thing that can happen in such a situation is roughening and flaking of the skin, irritation and peeling of the lips. If the epidermis is highly sensitive, much more serious problems may arise that will require a visit to a dermatologist.
Various diseases of the respiratory system . When the water content in the air is low, not only the outer integuments of a person, but also the internal mucous membranes experience a lack of it. The mucous membranes of the respiratory organs (nasal cavity, larynx, trachea, lungs) are no exception. This leads to their weakening and reduced ability to fight pathogens of respiratory diseases. This can lead to acute respiratory infections, rhinitis, sore throat, and tracheitis.
Respiratory irritation . Since the mucous membrane of the nasopharynx and respiratory tract dries out somewhat, unpleasant sensations arise: sore throat, discomfort when inhaling.

Stadler Form Selina Little Hygrometer White S-080

Country of origin: Switzerland. Very light model. Its weight is only 15 grams. The small overall dimensions of the device allow it to be carried in a clothing pocket. Using this model, you can measure not only relative air humidity, but also temperature. The latter indicator can be displayed on the screen in C° or F°.

The measurement error is +3%. The device has a convenient retractable stand and a large screen. If necessary, it can be mounted to a wall or cabinet. The range of measurement of air humidity is 10-98%, temperature – from -10 to +50 C°. The manufacturer's warranty period is 12 months.

Advantages:

portability;
light weight;
clear display of measurement results;
ease of installation and measurement.

No deficiencies found.

Scope of application of hygrometers

Problems requiring humidity control often arise in various industries. Modern manufacturers produce hygrometers designed for specific specific applications, which means they are best suited for use in a particular field of activity. Here are just a few examples of situations that can be solved using these measuring instruments:

For long-term storage of agricultural products, for example, in vegetable stores or granaries, it is necessary to maintain temperature and humidity conditions. This can be achieved by constantly monitoring the microclimate using a hygrometer.
Many medications require special storage conditions and may lose their properties if they are exposed to excess humidity.
A hygrometer is also necessary in a library, since books, especially old ones, deteriorate much faster in a humid microclimate. Materials that are many years old can deteriorate from excess moisture, which means that air humidity needs to be controlled to ensure optimal storage conditions.
The need to control the moisture content of materials often arises at a construction site. For example, the degree of drying of wood is checked to determine whether and how it can be used as a building material. There are also specialized hygrometers designed to determine the moisture content of concrete.
Checking the moisture content of materials is often carried out during the production of furniture, because a product made from too damp or overdried wood was produced in violation of the technology and, most likely, will last much less.

Megeon 20207

Country of origin: China. The electronic hygrometer has a wide LCD screen that is easy to visualize, on which all measurement indicators are simultaneously displayed. With this model you can measure relative humidity and temperature. There is a memory for storing previous measurements.

The model has a push-button control device, small size and light weight. The design is equipped with an alarm clock, clock and calendar. The model is intended for taking measurements at home and in office premises. Powered by AAA battery. Operating voltage 1.5 V. The device can operate in the temperature range from -50 to +70°C. This allows it to be used in unheated buildings. Measurement error +5%.

Advantages:

compactness and light weight;
economical power consumption;
ease of operation;
heat resistance.

Main disadvantage:

high percentage of error.

TOP 13 best hygrometers

Photo	Name	Rating	Price
The best contact digital thermohygrometers
#1		ADA instruments ZHT 70	⭐ 5 / 5	Find out the price
#2		CEM DT-125H	⭐ 4.95 / 5	Find out the price
#3		CEM DT-129	⭐ 4.9 / 5	Find out the price
#4		MEGEON 20610	⭐ 4.85 / 5	Find out the price
#5		Testo 606-1	⭐ 4.8 / 5	Find out the price
#6		CEM DT-125G	⭐ 4.75 / 5	Find out the price
The best non-contact hygrometers moisture meters
#1		ADA instruments ZHT 100-70	⭐ 5 / 5	Find out the price
#2		ADA instruments AeroPipe	⭐ 4.95 / 5	Find out the price
#3		Xiaomi Mijia Hygrometer Bluetooth	⭐ 4.9 / 5 1 - voice	Find out the price
#4		Anymetre TH101B	⭐ 4.85 / 5 1 - voice	Find out the price
#5		Xiaomi MiJia Miaomiaoce E-Ink	⭐ 4.8 / 5	Find out the price
#6		CEM DT-321	⭐ 4.75 / 5	Find out the price
#7		CEM DT-625	⭐ 4.7 / 5	Find out the price

Which hygrometer would you choose or recommend?

Take the survey

CEM DT-322

Country of origin: China. The model is intended for measuring relative air humidity and temperature in domestic and office premises. Measurement range: temperature - from 0 to 50°C, humidity - from 10 to 90%. The design has a built-in alarm clock and calendar. Temperature can be measured by the device in C° or F°. Model weight 74 grams. The latest readings from the device are stored in its memory. Measurement error +5%.

Advantages:

compactness;
ease of operation;
maintaining measurement statistics;
convenient screen and controls.

Main disadvantage:

Slow sensor operation.

What relative humidity should be in a living space?

Medical scientists have found that in order for a person to feel most comfortable, the room temperature should be +20 ° C and the humidity from 30 to 45%.

If the relative humidity (φ, %) is below the established range, the air is considered dry. A person who will be in such a room will feel a dry throat, he will begin to cough, and his hair and skin will become dry. Houseplants will also be susceptible to disease and will likely dry out.

On the contrary, if the actual relative humidity exceeds the upper permissible level, such a room will feel damp, and excess moisture will saturate the furniture, walls, books, bed and things. People with respiratory diseases especially suffer in damp rooms.

Humidity in the house is regulated using special dehumidifiers or humidifiers, as well as other climate control equipment, such as air heaters, air conditioners and gas boilers. It is important to know the current state of this parameter, and for this it needs to be periodically checked with a hygrometer.

Laserliner ClimaCheck 082.028A

The German brand is made in China. The electronic device is designed to measure temperature and relative humidity in domestic and office premises. The model is equipped with a convenient digital display. Temperature can be measured in C° or F°. The design has a convenient magnetic fastening. The humidity measurement range is from 20 to 99%. Measurement error +1%. The weight of the device is 180 grams.

Advantages:

ease of operation;
compactness and light weight;
multifunctionality.

Main disadvantage:

inconvenient narrow screen.

Portable

The main areas of application for portable hygrometers are the oil and gas and petrochemical industries. Using such a device, the microhumidity of gas in cylinders or pipelines is determined. They can operate over a wide temperature range and output humidity in different units of measurement. The compactness of the hygrometer allows you to easily take measurements at the right points.

G337

Country of origin: China. An alcohol hygrometer can measure temperature and relative humidity indoors and outdoors. Measurement range: temperature – from -40 to +50 C°, humidity – from 0 to 100%. The device body is equipped with a loop for wall mounting and is made of plastic. Model weight 50 grams.

Advantages:

safety;
does not require batteries or battery recharging;
versatility of use;
light weight.

Main disadvantage:

outdated design.

Description of the indicator and the importance of compliance

To make a room comfortable, it must have the appropriate temperature and humidity. The latter indicator is characterized by the amount of steam in the air. Its level may rise or fall depending on the situation.

For example, if a family actively uses heating and air conditioning systems, the air becomes dry. The lack of exhaust hood and ventilation leads to the formation of dampness in the apartment.

Dryness is harmful for people prone to allergic reactions and colds. A humid climate promotes the growth of mold on walls.

Special devices help to monitor the parameters. They will help to promptly identify deviations from the norm and eliminate the problem before it can harm residents.

Boneco A7057

Country of origin: Germany. The mechanical hygrometer is designed to measure relative air humidity in domestic and office premises. The model has a white plastic body. The device can be attached to the wall using a sticky element. Measurement readings are displayed on a scale having a measurement range from 20 to 100%. Measurement error +5%.

Advantages:

compactness;
nice design;
low cost.

Flaws:

the device requires calibration before starting work;
short warranty period.

How to choose the right hygrometer

The correct choice of a hygrometer is primarily related to the number of measurements.

If you need constant control of the humid environment, then choose digital devices. For single measurements, for example, in a house or bathhouse, you can purchase a mechanical hygrometer. Before buying such a device, experts advise reading on the Internet the ratings of hygrometers among leading manufacturers and reviews from real owners of the devices. This information will allow you to determine which hygrometer is the most accurate and reliable.

VIT-2

Country of origin: Russia. The psychometric type hygrometer is designed for measuring temperature and relative humidity in domestic, office and warehouse premises. The body of the model is made of plastic and has a mount for hanging on the wall. The instrument readings are displayed on a metal scale. Relative humidity measurement range from 20 to 90%.

Dignity:

low cost;
simplicity of design.

Main disadvantage:

the need to periodically add distilled water to the device.

It's flowing through the windows

Excessive moisture in the air literally has a deplorable effect on the condition of the objects around us. The inner surface of the windows becomes covered with drops of moisture, which flows onto the windowsill. Bed linen, clothing, and fur products acquire an unpleasant damp smell and are inconvenient and unpleasant to use.

Food spoils and is impossible to eat. Enclosing structures and finishing become covered with mold. Its spores spread through the air and can cause allergic reactions and a sharp decrease in immunity. A person gets sick more often, and the recovery process takes longer.

TFA 45.2033

Country of origin: Germany. The mechanical type hygrometer is made in the shape of a circle. The case has a brass ring and an informative dial, which is divided into comfort zones. Measuring range: humidity from 0 to 100%, temperature from -15 to +55C°. The device has a wall mount.

Advantages:

low cost;
ease of operation;
wall mounting option.

Main disadvantage:

When direct sunlight hits the device, it gives readings with a large error.

Voting for the best hygrometer

Which hygrometer would you choose or recommend?

ADA instruments ZHT 70

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CEM DT-125H

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CEM DT-129

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MEGEON 20610

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Testo 606-1

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CEM DT-125G

0.00 % ( 0 )

ADA instruments ZHT 100-70

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ADA instruments AeroPipe

0.00 % ( 0 )

Xiaomi Mijia Hygrometer Bluetooth

50.00 % ( 1 )

Anymetre TH101B

50.00 % ( 1 )

Xiaomi MiJia Miaomiaoce E-Ink

0.00 % ( 0 )

CEM DT-321

0.00 % ( 0 )

Sawo 115-HA

The Finnish brand is made in the Philippines. The body of the model is made of aspen and has the shape of a house. The original design of the device allows it to be used as an element of interior decor. Measurement readings are displayed on a large graphic dial. The model can be used to control the relative humidity in a steam room. At high temperatures, the hygrometer body begins to emit a pleasant woody aroma. The humidity measurement range of the device is from 0 to 100%.

Advantages:

low cost;
high accuracy;
ease of operation;
Possibility of use in rooms with high humidity and temperature.

Flaws:

there is no protective glass on the dial;
no temperature measurement function.

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).

Harvia SAC92200

Country of origin: Finland. The body of the model is made of wood in eco-style. It has the shape of a rounded square, into which a clear dial is inserted, the measurement step of which is 10 units. The body material is birch. The model has a hair operating principle. Measuring range: pressure from 0 to 100%, temperature - from -15 to +55C° .

Advantages:

nice design;
low cost;
high accuracy;
ease of operation.

Main disadvantage:

long period of response to changes in air humidity.

Stationary

Stationary hygrometers allow not only to take measurements, but also to control technological processes. The design of the device allows you to detect even a small percentage of microhumidity. The sensor heating system makes measurements more accurate because it prevents exposure to drying agents that may be contained in the gas mixture.

Question answer

Should household hygrometers be certified by metrological services?

Household hygrometers do not require such certification, because devices for such purposes are not subject to requirements for high accuracy of readings.

What error indicator can be considered optimal for household appliances that measure relative air humidity?

The maximum permissible error for household appliances is 3-4%.

How long should measurements be taken to obtain a more accurate measurement result?

Household appliances measure relative air humidity within 40-60 seconds. The measurement speed of professional devices is 1-5 seconds.

Can household hygrometers be used to determine relative air humidity and be used to measure the moisture content of bulk materials?

To determine the moisture content of raw materials, manufacturers produce contact devices that have a narrow specialization: for wood, bulk materials, etc.

What measurement range should household hygrometers have?

It all depends on the intended installation location of the device. The range of measurement of relative air humidity should be: for the bathroom and kitchen from 0 to 100%, for living rooms and corridors from 20 to 80%.

Controlling relative air humidity allows you to create comfortable living conditions in residential and working conditions in office spaces. For these purposes, household, non-contact hygrometers are used.

How to measure humidity?

The home atmosphere is tidied up using special humidifiers or dehumidifiers. However, in order to make these devices work as efficiently as possible and not cause further harm, you will first need to measure the level of moisture content in the surrounding air. For this purpose, devices called household hygrometers are used.

All hygrometers can be divided into two large groups.

Mechanical . They are distinguished by reliability and low price. They serve for a long time. However, they have one drawback - not very accurate readings. The principle of operation is to measure the weight of water collected from the air over a certain time (it condenses in special curved tubes). The measurement result is displayed on a clock-like dial.
Digital . This category of devices is more expensive and less reliable. However, it is distinguished by its extraordinary ease of use and the almost complete absence of errors in the readings. Digital hygrometers receive information about the water content in the atmosphere from a special electronic sensor. After this, the information is processed and displayed on the liquid crystal screen of the device. They often combine a hygrometer, thermometer, barometer and some other devices.