Which room hygrometer to buy? All about devices designed to measure air humidity. What a hygrometer measures.

Everyone knows what a thermometer is, some of you have heard the word “hygrometer,” but probably many have no idea what kind of object it is or what its purpose is. Let's try to figure it out.

Hygrometer: definition, types and purpose

A hygrometer is a various types and types, designs and functional purpose. We are interested in a room hygrometer, which can be used separately or as part of home weather station. Common brands of devices: Testo, Tefal and others.

Based on the principle of the device, they distinguish the following types hygrometers:

Weight. Determines the quantitative content of water vapor in grams per cubic meter air.

Based on measuring the difference between wet and dry thermometer readings.

Hair. It uses the property of human hair, which shortens and lengthens as it decreases and increases. relative humidity air accordingly.

Condenser. This room hygrometer is based on the technology of cooling the air to the so-called “dew point” with condensation of water vapor.

To measure air in laboratory conditions, they mainly use weight and Hair hygrometers effective for low temperatures- a psychrometer, say, stops working at -10 degrees.

To measure humidity in apartments, psychrometric hygrometers are usually used. They are easy to use, reliable and optimal for measurements at positive temperatures. Hair machines also have a certain popularity.

It's up to you to decide whether to buy an electronic (digital) or mechanical, wall-mounted or tabletop hygrometer. Our goal is to show all the benefits of such an acquisition.

What benefits does this device bring?

Hygrometers are not very popular now, but in vain. Most people can't even imagine how useful this amazing parting can be.

First of all, it is indispensable for forecasting weather conditions. Ideal for these purposes room hygrometer, which can be installed in a forest house or cottage, at a recreation center, etc. By placing it indoors so that the hygrometer comes into contact with the air from the street.

A hygrometer is also very useful in determining the humidity in your home or apartment, especially if there are small children in it. So, if there is no temperature, you need to maintain a little high humidity. If the apartment is cold for some reason, the humidity should be lowered. Inexpensive indoor hygrometer indispensable assistant in effective regulation of living room humidity.

There are other benefits from this amazing device. You can use it to control humidity in the cellar, while maintaining beneficial features valuable food products.

Design and principle of operation using the example of the Vit 1 thermohygrometer

This device is made of polystyrene or materials with similar properties. Hygrometer Vit 1 is a psychrometric device. Its operation is based on the relationship between air humidity and the difference in the readings of the wet and dry thermometers, which are in thermodynamic equilibrium with the environment.

Attached to the base of Vit 1 are two thermometers with scales, a glass feeder filled with distilled water and a psychrometric table. A wet thermometer draws moisture from the feeder via a wick.

We take readings from both thermometers, determine the difference in readings and, based on the readings of the dry thermometer and the difference between the dry and wet thermometers, determine the humidity according to the psychrometric table.

This indoor hygrometer is simply irreplaceable at home.

They call it a hygrometer measuring device, which is used to determine the humidity in the room or the humidity of materials.

Depending on the scope of application, non-contact and contact hygrometers are distinguished.

Non-contact hygrometers

Non-contact hygrometers measure air humidity. Their operating principle is based on the ability of certain substances and materials to change their properties depending on the level of air humidity.

Depending on the principle of operation, there are several types of hygrometers:

Psychrometric hygrometer: the operation of the device is based on changing the rate of moisture evaporation depending on the level of humidity in the room. The evaporation process is accompanied by the absorption of energy, which entails a decrease in temperature. A room psychrometer consists of two thermometers, one of which is dry, and the second is wrapped in a cloth soaked in water. Based on the difference in the temperature readings of the wet and dry thermometer, the humidity in the room is determined using tables.

Hair hygrometer p: its action is based on the property of hair to change its length depending on the humidity in the room. To do this, the fat-free hair is pulled onto a frame connected to the arrow of the device. The hair hygrometer allows you to measure indoor humidity with high accuracy in the range from 30 to 100%.

Film hygrometer: its action is based on the ability of a film made from some organic materials to change its size depending on humidity. To do this, the film membrane is stretched over the frame to which the arrow of the device is connected. When the position of the center of the membrane changes, the position of the hygrometer needle changes and its readings are recorded.
Weight hygrometer. The device is a complex of curved tubes filled with hygroscopic material. When air is passed through it, the filler absorbs moisture, which leads to an increase in its weight. By weighing the device before starting to measure humidity and after passing air through it, determine absolute humidity air. A weighing hygrometer allows you to obtain accurate results, but it is mainly used only in laboratory conditions.
Electrolytic hygrometer. The operation of the device is based on the property of the electrolyte to change electrical resistance depending on the concentration of the substance. To do this, a film of hygroscopic electrolyte is applied to the surface of a glass plate and current is passed through it. The electrolyte concentration depends on the humidity level in the room. By measuring the electrical resistance of the plate, you can accurately measure the level of humidity in the room.
Ceramic hygrometer. The principle of operation of this device is similar to the principle of operation of an electrolytic hygrometer, with the only difference being that the medium that changes the electrical resistance depending on humidity in this case is clay, silicon or oxides of some metals.

: devices may have different principles of operation. In particular, they distinguish capacitive hygrometers, measuring the capacitance of the capacitor, which changes depending on the level of humidity; and resistor devices, measuring the conductivity of the working substance depending on the level of humidity. It should be noted that capacitive electronic hygrometers wear out faster and the device fails.

Contact hygrometers measure the moisture level of materials, such as wood or fabric, when long-term storage. They are necessary in warehouses and enterprises, where the quality of materials and their shelf life depend on the level of humidity.

To measure, a contact hygrometer must be brought into contact with the material whose moisture level is to be measured. For this purpose, the devices are equipped with special sensors.

For example, a needle hygrometer has sensors in the form of two needles immersed in the medium being measured. Passed between needles electricity and at the same time the electrical resistance of the medium is measured. The obtained values are compared with the resistance of the dry material, and based on this comparison the moisture level is determined. A needle hygrometer allows you to determine the level of humidity with a high degree of accuracy.

Another type of contact hygrometer is induction. This device is equipped with a set of sensors that must be placed on the surface of objects to measure. It is convenient to use, does not damage the surface of the material, but is inferior to a needle hygrometer in measurement accuracy.

What to give preference

A psychrometric hygrometer allows you to obtain fairly accurate readings of the humidity level in a room, but it is not always convenient to use. It is unlikely that anyone will like to change the water in the instrument flask and make sure that the “wet” thermometer is really wet. However, if these difficulties do not frighten you, feel free to purchase a psychrometer.

Hair and film hygrometers are mechanical instruments. They are affordable, reliable and easy to use, but like everything else mechanical devices may have an error of 1 to 10%, which can be determined empirically, comparing their readings with the humidity value obtained by another, more accurate device, for example, a psychrometer. At household use The level of error of a mechanical hygrometer, as a rule, does not matter.

Electrolytic and ceramic hygrometers require a current source, such as a battery or battery, but with these devices you can get enough exact values humidity level.

Electronic hygrometers consist of a housing in which the device board and sensor are located, and a display on which the readings are displayed. In some devices, sensors can be remote and located outside the housing, which allows for remote measurements. For example, you can place a sensor in a steam room and monitor the humidity level while in the next room. Another advantage of an electronic hygrometer is the versatility of the device. Usually the device is also equipped with a thermometer and, in fact, is a weather station.

What are the prices for hygrometers?

A contact moisture meter costs from 2000 to 12500 thousand. Cost depends on trademark and materials for determining the moisture content of which the device is used.

A household hygrometer designed to measure indoor humidity can be purchased for 400 rubles. For example, hygrometers made in China Sawo trademark on Yandex. The market is sold at this price.

If desired, you can purchase devices that please the eye with their appearance, in a stone case, with optical illumination, but at a price from 5000 rubles and higher. For example, a brand hygrometer Tylo(Sweden) worth 2700 rub.., and the device is a brand Cariitti(Finland) can be purchased for 5,000 rubles.

Digital weather stations are affordable from 2000 to 35000 rubles.

HYGROMETER - a device for measuring air humidity. There are several types of hygrometers, the action of which is based on different principles: weight, hair, film, etc.
A gravimetric (absolute) hygrometer consists of a system of U-shaped tubes filled with a hygroscopic substance capable of absorbing moisture from the air. A certain amount of air is drawn through this system by a pump, the humidity of which is determined. Knowing the mass of the system before and after measurement, as well as the volume of air passed through, the absolute humidity is found.
Action hair hygrometer is based on the property of defatted human hair to change its length when air humidity changes, which makes it possible to measure relative humidity from 30 to 100%. The hair is pulled to metal frame. The change in hair length is transmitted to the arrow moving along the scale. A film hygrometer has a sensitive element made of an organic film, which expands when humidity increases and contracts when humidity decreases. The change in the position of the center of the film membrane is transmitted to the arrow. Hair and film hygrometer in winter time are the main instruments for measuring air humidity. The readings of the hair and film hygrometer are periodically compared with the readings of a more accurate device - a psychrometer, which is also used to measure air humidity.
In an electrolytic hygrometer, a plate of electrical insulating material (glass, polystyrene) is coated with a hygroscopic layer of electrolyte - lithium chloride - with a binder material. When air humidity changes, the concentration of the electrolyte changes, and therefore its resistance; The disadvantage of this hygrometer is that the readings depend on temperature.
The action of a ceramic hygrometer is based on the dependence electrical resistance hard and porous ceramic mass (a mixture of clay, silicon, kaolin and some metal oxides) from air humidity.
A condensation hygrometer determines the dew point by the temperature of a cooled metal mirror at the moment when traces of water (or ice) condensing from the surrounding air appear on it. A condensation hygrometer consists of a device for cooling a mirror, optical or electrical device, which records the moment of condensation, and a thermometer that measures the temperature of the mirror. In modern condensation hygrometers To cool the mirror, a semiconductor element is used, the operating principle of which is based on the Peltier effect, and the temperature of the mirror is measured by a wire resistance or semiconductor microthermometer built into it.
Heated electrolytic hygrometers, which are based on the principle of measuring dew point above saturated conditions, are becoming increasingly widespread. saline solution(usually lithium chloride), which for a given salt is in a known dependence on humidity. The sensitive element consists of a resistance thermometer, the body of which is covered with a fiberglass stocking soaked in a solution of lithium chloride, and two platinum wire electrodes wound over the stocking, to which an alternating voltage is applied.

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Few people know about the existence of such a device as a hygrometer. And, of course, not everyone knows the benefits that can be obtained from its use. First of all, it is health, which depends on living conditions and a comfortable microclimate. It's not just indicators temperature regime and air pollution, but also humidity parameters. Deviations from optimal values may contribute to serious illnesses. This is the main reason why it is worth buying an indoor hygrometer for every house or apartment, with the help of which you will be able to create ideal conditions for accommodation of all family members.

Electronic device

Before choosing the optimal moisture measuring device, you need to familiarize yourself with the principles of its operation. The main classification can be distinguished:

hygrometers;
psychrometers.

Despite the common end goals, the operating principles of a psychrometer and a hygrometer are different.

You can use primitive grandma’s methods - a glass filled with liquid using or fir cone, the scales of which open if the air is too dry.

Hygrometer: what is it?

A humidity measuring device is used to determine the comfortable microclimate in a room. Before deciding which hygrometer to buy for your apartment, it is important to know the basic classification and operating principle of each model.

Devices can be divided into 4 types.

Psychrometer;
hair device;
electronic;
condensation

The simplest devices use special tables with relative humidity parameters. Modern electronic models work using microcircuits; they independently take data and display it on the display.

Why should you buy a room hygrometer?

People's health depends on many factors. The condition of the air, in particular its humidity, plays an important role. Both high and low humidity are harmful. When elevated, viruses and microbes begin to multiply. Decreased levels lead to difficulty breathing and drying out of the mucous membranes.

Modern meters are additionally equipped with:

Operating principle of a hygrometer-psychrometer

Psychrometer translated from Greek means “cold yardstick (measurement). This is the basic answer to the question of what a hygrometer measures. In other words, it can be used to measure air temperature and humidity.Its operating principle is based on change physical properties liquids. During this process, water evaporates. It loses energy, therefore the temperature drops. This decrease is recorded with a wet thermometer.

Its main difference from a hygrometer is the principle of operation, the work of which is based on changes in physical and chemical properties substances when air humidity fluctuates.

Types of hygrometer designs

A device for measuring humidity must be purchased if there are small children in the house. And even more so if air conditioners are installed. Manufacturers offer models equipped with various functions. Each device has its own positive and negative properties, which are best known in advance.

Electronic

Indoor electronic thermometer-hygrometer Quickly measures indoor humidity readings. Inside the device, an electrolyte (lithium chloride) is applied to the plate. thin layer. Voltage passes through it and goes to the indicator panel.

Mechanical

To measure the humidity in a room, many people choose a mechanical model. It is easy to use and its price is lower than that of an electronic one. However, his readings may also have errors. The simplest devices are not certified and are not verified meteorological services. Therefore, in this case we cannot talk about the accuracy of the readings.For room mechanical hygrometers-thermometers, the location of their installation is important. Most often offered wall models, which does not always fit into the interior.

Basic rules for choosing a room hygrometer

In order to get the maximum benefit from the device, before choosing, you need to know how the hygrometer works, what measurements will be made with it, and determine the conditions of its operation. In addition, the external data of the hygrometer play an important role.

Measuring range

The devices can be supplemented with a built-in thermometer, which is used to measure air temperature. Before choosing a model, it is important to determine where it will be installed. Not always an acquisition expensive device, with which you can obtain boundary parameters, will be justified.

It is important that the selected device is designed for parameters close to the upper limit of the range. For example, heating temperature is important for a bath. You should choose a model that will withstand temperatures up to +120°C. This will prolong its functioning.

Error

Measurement accuracy is also important in certain cases. For example, in hospitals, warehouses. The psychrometer provides more accurate humidity data. Deviations of an electronic device can fluctuate within 5÷10%, of a condensation device – 1÷5%.

Humidity detection time

Many low-quality products from unknown manufacturers have been released onto the market. In the production of such devices, outdated techniques and methods for measuring humidity could have been used. Therefore, it is important to decide where to buy a room hygrometer, availability in point of sale relevant certificates for this product and especially important - guarantees.The device, which displays data after 1 minute, shows information and humidity a minute ago. – these are invalid parameters.

Choice additional functions in the device increases the cost of the hygrometer. Therefore, deciding on the feasibility of such a device for home use needed in each case separately. Let us present for your acquaintance the main functions of digital models.

Review of the main models of room hygrometers

Manufacturers have launched a variety of models on the market, both in terms of function and cost. You can buy a completely budget mechanical hygrometer, or choose a weather station with additional functions.

We offer an overview of the most popular hygrometers.

Model VIT-2

The VIT-2 device can be called the most popular.

The operating temperature range varies from -15° to +40°C;
thanks to the division value of 0.2°, you can obtain fairly accurate information about humidity;
filled with toluene, which is safe for household use.

Model PB-08

This model is equipped with a thermometer and barometer. The stylish wooden case reliably protects the mechanism from external influences. A hygrometer has a number of advantages:

high measurement accuracy;
presence of a barometer;
stylish design.

The device is a bestseller in the budget category, which does not affect the accuracy of its measurements. The advantages include:

the hygrometer is equipped with a high-resolution display;
additionally built-in thermometer;
small error;
compact size.

How to use a hygrometer

The hygrometer is quite easy to use. The operating principle is based on monitoring changes in the parameters of dry and humidified thermometers. They constantly measure the environment. Based on the temperature difference, the air humidity parameter is calculated.

In the simplest hygrometer, humidity is determined from a table on which the corresponding temperature data is plotted;
modern electronic devices calculate these parameters independently and display the final values on the display.

User reviews of room hygrometers

Before choosing optimal model You should familiarize yourself with the opinions of device users. They will reliably tell you about all the nuances that arise during operation.

Hygrometer Boneco 7057

Neo Russia: Advantages: helps you understand whether you need a humidifier or not, durable, lightweight, attaches to any surface
Disadvantages: there are doubts about high accuracy
We purchased this hygrometer when our daughter was just born, in order to somehow determine whether the house was dry or not. IN winter period this is especially true, since the air in the apartment is especially dry due to heating...
More details on Otzovik: https://otzovik.com/review_4637786.html

Digital thermo-hygrometer with clock T-07

zaripova Russia, Perm: Advantages: compact, accurate.
Disadvantages: no
We bought an air humidifier. Works. And immediately disputes arose - one thinks that the humidity in the room is already high, and the other thinks that it is insufficient. The purchased humidifier does not have a built-in hygrometer, that’s the problem. I had to buy a hygrometer separately.
We bought a digital thermo-hygrometer with a T-07 clock at the Medtekhnika store. A small device that does not take up much space on the table...
More details on Otzovik: https://otzovik.com/review_4093216.html

How to make a hygrometer with your own hands

There are several options for making the device yourself. We invite you to get to know the most in a simple way measuring humidity using a napkin. The principle of its operation is based on the absorption of moisture. The movement of the wire arrow will indicate a change in the humidity in the room. You can use a store-bought device to apply a scale of values on a napkin.

A hygrometer is an instrument used to measure the humidity in the atmosphere, indoors, or other enclosed space. How to use a hygrometer? It usually does not measure humidity itself, but determines indirect changes in the properties of a substance when absorbing moisture, on the basis of which the humidity indicator is determined through calculations.

Modern electronic devices use condensation temperature (dew point). Normal use The purpose of a hygrometer is to monitor weather conditions and obtain information to make a weather forecast. Combined with temperature, barometric pressure and wind speed data, humidity tells a lot about the weather ahead. For example, low Atmosphere pressure, associated with low temperatures and high humidity levels, indicates that rain is coming soon. A person needs such data so that he can comfortably organize his affairs.

Humidity is more difficult to measure than temperature, which is why the first hygrometers were not entirely accurate. Leonardo da Vinci invented the first version of the hygrometer already at the end of 1400. Guillaume Amontons invented the hygrometer, which was similar to a three-fluid barometer, in 1687. In 1781, Horace Benedict de Saussure (1740-1799) discovered that human hair is a good indicator of moisture. A major breakthrough in hygrometry was made in 1802 by British explorer John Dalton (1766-1844). He showed that the amount of water vapor required for saturation depends strongly on temperature. This led to an understanding of relative humidity and how to use a psychrometric hygrometer.

The moisture meter readings are interchangeable, simple calculations they are converted from one type to another - relative humidity helps determine the dew point or absolute humidity.

In order to learn how to use a hygrometer, you need to consider the main types of devices for measuring humidity. The psychrometer consists of two separate thermometers mounted on one body. One is dry and the other is wet (wet). The lower end of the wet thermometer is covered with a special cloth that acts as a wick. It is constantly in the water, cooling and wetting the wet bulb. At temperatures (T) above the freezing point of water, the wick reduces the wet-bulb temperature, which is usually lower than the dry-bulb temperature. However, when the temperature of the air drops below zero, the wet bulb becomes covered with a thin layer of ice, and it can be warmer than the dry bulb.

Relative humidity is calculated based on the ambient temperature, dry bulb temperature, and the temperature difference between the dry and wet bulb temperatures. Relative humidity is determined using a psychrometric chart. When two temperatures are equal, the air is completely saturated, and the greater their difference, the drier the air. Using special tables, knowing the T air and the psychrometric difference (T - T m), the remaining air parameters are determined. Psychrometers are commonly used in meteorology and in residential and residential HVAC systems. public buildings.

Electronic mirror dew point hydrometer

The dew point is the temperature at which a sample of moist air (or any other water vapor) at constant pressure reaches water vapor saturation. At this saturation temperature, further cooling causes water to condense. How to use an electronic hygrometer? Electronic mirror dew point hydrometers are among the most accurate instruments available today. They use a cooled mirror and an optoelectronic mechanism to detect microcondensation on the mirror surface.

The mirror temperature is controlled electronically feedback to maintain dynamic equilibrium between evaporation and condensation, thereby carefully measuring the dew point temperature. These devices require frequent cleaning, a trained operator, and periodic calibration to achieve high level accuracy. More recently, spectroscopic cooled mirrors have been introduced. In them, the dew point is determined using spectroscopic analysis, specifying the nature of condensation. Their main advantage is that they operate at temperatures down to -70°C.

Indoor hygrometer: types and functions of the device

The psychrometric method is used to change air humidity in residential, public and industrial buildings. How to use a psychrometric hygrometer? The device consists of two thermometers. The end of one of the thermometers, in the psychrometric body on the right, is wrapped with the end of a small cloth - a wick (medical bandage) in several layers, and the second is lowered into a container with clean water. The glass is closed with a special lid, which has a hole for the wick. The wet bulb temperature begins to drop as heat is absorbed; the equilibrium point between evaporation and the decrease in wet bulb temperature occurs after approximately 30 minutes.

A dry bulb measures the temperature of the indoor air in a room, while a wet bulb measures the temperature of the indoor air. How to use a psychometric hygrometer is described in detail in the instructions that come with the device. The panel contains psychrometric tables for determining air humidity. Removal is carried out by an employee without delay, since a long stay near the device can change the readings and distort the result of measuring humidity. For the most accurate result, the device must be installed so that the operator’s eyes are located at the level of the meniscus of the thermometers.

The most common indoor psychrometers are the thermometer-hygrometer VIT-1 and VIT-2. Structurally, they are very similar, but have significant differences in the field of application, so VIT-1 is used when the air temperature in the room is from 0°C to +25°C, and VIT-2 is from +15°C to +40°C.

An example of determining air humidity with a psychrometer:

Dry bulb temperature: +23.0°C;
wet: +20.5°C;
temperature difference: +2.5°C;
Using the psychrometric table on the panel, we determine the relative humidity: 77%.

This indicator of relative humidity is unacceptable, since GOST 30494-96 “Indoor microclimate parameters” establishes the following humidity standards:

Winter/autumn - 30-45%;
spring/summer - 30-60%.

Ways to reduce indoor humidity:

In winter. Ventilate the apartment. It is better if there is a possibility through supply ventilation warm air.
Use a dehumidifier.
Find possible leaks in water supply networks.
Use air conditioning in heating mode.
Turn on the kitchen hood.

Hygrometer VIT-1

VIT-1 measures humidity in rooms where the air condition is strictly controlled: on poultry farms, in libraries, in educational and medical institutions, if the internal air temperature does not exceed +25°C. How to use a hygrometer? VIT-1 is used at humidity from 20 to 90%, T from 5°C to +25°C. The VIT-1 wet thermometer is filled with toluene, and the wick is moistened with clean or rain water. The dimensions of the device are 290 mm x 120 mm x 50 mm. The device is inspected by government authorities every two years.

Hygrometer VIT-2

The design of VIT-2 is practically no different from VIT-1. The plastic case contains thermometers, a feeder and a table for calculations. How to use the VIT 2 hygrometer? The principle of operation is no different from VIT-1, but their psychrometric tables are different, therefore the calculations for humidity also differ.

First, the dry T is determined, then the wet T, and the required value is determined from the delta T at the intersection point of the “dry” thermometer using the psychrometric table. Speed air environment should be no more than 2 m/s so as not to distort the measurements.

The KTJ-TA218A moisture meter is suitable for measuring indoor humidity and temperature levels. How to use the TA218a hygrometer? A thermohygrometer or digital thermohygrometer is electronic device, which measures and displays temperature (T) and relative humidity (RH). Applications: ventilation and air conditioning, climate control, hospitals, food enterprises, saunas, GYM's, offices, conference rooms, museums, libraries, archives, computer rooms, printing, warehouse or home automation.

Device characteristics:

measurement range external temperature: 0°C - 50°C.
Display indication: C/F.
Humidity measurement range: 10-95% RH.
Temperature measurement accuracy: +/- 1°C.
Humidity measurement accuracy: +/- 5%.
cable length: ~ 2 m.
supply voltage: 1.5 V direct current AAA.
Display: 3.8 inches.

Moisture meter MODEL C-02

The device measures CO2, T and humidity, with a triple LCD display. How to use a hygrometer? MODEL C-02 T wet bulb thermometer and dew point function. Dual band infrared CO2 sensor.

The device performs:

Automatic measurement log keeping with data transfer to a PC. Data Hold: Freezes the display.
Low battery indicator.
Operating temperature: 5°C to 50°C.
Operating humidity: -10 to 90% humidity.
Storage humidity: 10 to 90% relative humidity.
Accuracy: CO2: ±3% or ±50ppm,
Humidity: ±5% RH,
Temperature: ±1 C, ±1.8 F.
Automatic memory capacity: 20,000 measurements.
Serial interface RS-232.

GAOTek Mini Temperature and Humidity Hydrometer

The GAOTek Mini Hygrometer is designed with an integrated measurement function over a wet bulb temperature range of 0°C to 80°C. How to use a hygrometer correctly? The integrated measurement function is ambient temperature, humidity, dew point and wet bulb temperature. This is a digital T meter with high accuracy and low power consumption. It is equipped with humidity sensors and an industrial-grade digital display. It is suitable for measuring T and humidity in any industrial sector, in workshops, factory warehouses, libraries, offices, laboratories, etc.

Model features:

high productivity and accuracy;
fast reaction time;
control of dry and wet thermometers;
microprocessor design;
sleep mode;
screen hold;
backlight function;
low power consumption;
digital screen;
dew point temperature;
temperature range from -30°C to +100°C;
Humidity range 0% to 100% rh;
dew point temperature from -30°C to +100°C;
wet bulb temperature 0°C to 80°C;
humidity accuracy 2% rh (from 20% to 80% at + 25°C);
response time 10 seconds (90% T+25°C).

Hydrometer Testo 645

Dual-channel measurement of T and humidity. Very precise measurement humidity up to ± 1% rF s internal memory measurements. How to use a hygrometer? Testo 645 displays the following values at the touch of a button: humidity, dew point, enthalpy and temperature. Convenient evaluation of measurement data with transfer to a PC and indicating the measurement location. Maximum humidity 100%. Minimum humidity 0%. Temperature from -50°C to +150°C.

5 reasons why you need to regularly measure indoor moisture

You need to learn how to properly use a psychrometric hygrometer in order to regularly measure the humidity in environment, since it seriously affects human life.

Comfort at home. People spend much more time at home than outside, so measuring the humidity at home is very important to create a comfortable living environment. After all, only by determining the moisture content in the air can you decide whether you need to turn on the heating or ventilation system. Humidity directly affects the comfort in the apartment, and it is recommended to maintain its value in the range from 25 to 55% or, even better, from 40 to 50%. Humidifiers and dehumidifiers can be used to ensure that home occupants always feel great, no matter what the weather is like outside.
Health protection. Inadequate humidity levels pose potential health risks. If the humidity in the home is too high, there is a risk of mold and bacteria growing, some of which are extremely dangerous, especially when children live in the home. Excessively dry air is another problematic factor and can cause itchy skin, coughing, and other painful symptoms. Dry air is a breeding ground for allergens. By measuring humidity, you can achieve optimal parameters air to provide healthy image life.
Security of property. Too much moisture in the air and the house will become filled with mold and mildew. Warm and wet air- the perfect recipe for mold, which will grow everywhere: in the shower, kitchen, food, furniture and books. Once you determine that the humidity is high, you will need to thoroughly ventilate the house and dry the air with an air conditioner or dehumidifier. A moisture testing tool can help monitor humidity. Dry air can cause damage musical instruments or furniture, as the wood may crack and warp. You can save a lot of money on expensive repairs or replacement of furniture if you control the humidity in a timely manner.
Animal protection. Humidity can be detrimental to pets, sometimes even more so than to humans; humidity must be carefully controlled to keep animals comfortable.
Harvest safety. Without a reliable hygrometer, it is impossible to grow crops in a greenhouse or conservatory, where it is necessary to maintain specific plant parameters. Too much moisture and you'll have to deal with root rot, fungi and a host of other problems that are best avoided by keeping the humidity at the right level.