From this article you can find out what should be a device for measuring humidity. The text describes the main types of devices designed to control climate by measuring the water vapor in the air. It describes the existing types of devices, their technical and operational features, rules of use.
Instrument for measuring air humidity and its specificity
Humidity affects the state of the furnishings, household appliances and human well-being. The presence of water vapor in a certain amount in the air depends on the following factors: technogenic impact, climatic features of the region, the state of communications and construction in general, as well as the operating conditions of the room.
The humidity standard for a healthy person is considered to be 40-60%. To create optimal conditions, special devices are used. Depending on the needs, these can be dehumidifiers or humidifiers. To coordinate the operation of these devices, air humidity meters are used.
Note! There are air conditioning systems with an automated function to control the level of moisture. This type of equipment independently measures the air readings and adjusts them to the norm.
You can measure the amount of water vapor at home by using improvised means, such as a spruce cone, whose scales open up if the room is dry, or to monitor the condition of the condensate after you have cooled the container with water.
The method of assuming the use of capacity is based on how condensate behaves on cooled surfaces and how fast it evaporates. The medium in an enclosed space under the condition of balanced processes of condensation and evaporation is in a state of saturated steam. If the amount of moisture in a saturated vapor is close to the concentration of water vapor in the air of the room, the evaporation process will be difficult. This will indicate the presence of excessive moisture in the room.
How to measure the humidity in the apartment with the help of a glass:
- Fill a glass container with water. For these purposes, suitable not only glass, but also a bottle, a can.
- Set the container in the refrigerator for a couple of hours.
- After that, get a glass and measure the temperature of the water. This indicator should not exceed 50 ° С.
- The control vessel should be placed in the room, away from heating devices.
Note! It is necessary to note the time to observe the behavior of the condensate. It takes from 5 to 10 minutes.
If the condensate accumulated on the walls dries out within the indicated time, it means that the room is dry. Wet glass indicates that the room has optimal conditions with a sufficient level of humidity. If the drops of condensate are large and flow down the walls of the vessel, this indicates an increased amount of water vapor in the room.
More accurate data can be obtained using special devices. For these purposes, there are several types of devices. The most primitive devices that measure the humidity of the air in a room are called hygrometers.
This category of devices includes the following types of devices:
Each type of the listed devices functions due to a certain principle of operation, for example, the structural feature of the hair device is the presence of U-shaped tubes. Condensation hygrometer is considered the most accurate. It takes measurements with the minimum error.
There is another category of instruments for measuring the humidity of air, they are called psychrometers. Varieties of psychrometers:
Station version of the device – the most popular of them. Its design includes a pair of thermometers mounted on a tripod. A dry thermometer indicates the temperature of the air in the room, while the wet thermometer is wrapped with a cloth, one end of which is dipped into a tank filled with liquid (water).
Note! Do not lower the end of the wet thermometer directly into the tank, otherwise it will display the temperature of the water, and not the air masses circulating above it. There should be a distance of at least 30-40 mm between the end of the device and the container.
The state of human health depends on a large number of factors. An important role in this is given to the purity and moisture of the air. If the moisture in the room is not enough, the mucous membranes of the respiratory tract will dry out, as a result of which a person can develop diseases associated with the vital activity of harmful bacteria.
The simplest hygrometers assume the use of the table of relative humidity of air, according to the temperature indicated in it, you can get an idea of the current state of the microclimate. In more advanced models, there is a set of chips, which independently perform calculations and display the result on the screen in electronic form.
In addition to traditional designs, the offer of the modern market allows you to buy moisture meters with additional functionality. Such devices display other data on the screen:
- air temperature in the room;
- current time and date;
- level of atmospheric pressure.
Note! Some types of fixtures are equipped with an indication system. It informs the owner if the indoor climate is outside the normal range. This feature allows you to quickly notice the problem and fix it.
This type of device is used to determine the moisture index in the range of 30-80%. The design of the device consists of several elements:
- metal frame in the form of a frame;
- measuring scale (the step of each division corresponds to 1% humidity);
- human hair (fat free);
- adjustable with a screw arrow;
- pulley, designed so that you can throw the free end of the hair with a fixed weight.
Hair hygrometer is a type of measuring device designed to determine the humidity of air, the principle of action of which is based on the hygroscopicity of a human hair, in other words, the ability to lengthen or shorten under the influence of moisture. When the humidity in the room decreases or increases, the tension of the hair weakens or, on the contrary, increases. As a result, the pulley rotates and sets in motion an arrow pointing to the scale. Due to this, it is possible to determine the exact indicator of environmental humidity.
Hair type hygrometer has a significant advantage over other devices. The air temperature cannot influence its readings, as it happens with electrolytic models. Electricity is not required for its operation; the hygrometer functions through mechanical processes.
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In order to identify the current level of humidity in a room, two values should be known: a relative humidity indicator and an absolute value. The percentage ratio between them is the desired parameter. Therefore, it will be useful to know the name of the device for measuring the humidity of air in its absolute value and the principle of its operation. A weight hygrometer measures the amount of water vapor contained in one unit of air (1 m?).
The device includes several U-tubes forming the system. Inside there is a hygroscopic substance that absorbs moisture from air masses. The system passes a certain amount of air, which is taken from one point. This design allows you to determine the mass of air inlet and outlet, as well as its volume. The absolute value is determined by mathematical calculations.
Interesting fact! The study of water vapor as a component of air began in the 16th century. The author of the first scientific work on this topic was J. Port. It was published in the 17th century. After the heyday of steam engines in the 19-20 centuries. water vapor again interested scientists. After serious research in this area in 1963, the Fourth International Conference was held on its physical characteristics.
Ceramic devices are a commonly used type of moisture meter, moisture meters of this type are simple and operate mechanically. The device is made of ceramic material, which can be porous or solid. It contains metal elements. Ceramic mass has electrical resistance, and the humidity of the room has a direct impact on the level of this resistance.
In order for the mechanical design of the device for determining the humidity of the air in a room to function properly, certain metal oxides must be included in the ceramic material. Silicon, clay and kaolin are used as the basis.
Condensation hygrometer allows you to get the most accurate indicators that reflect the climatic comfort of the room. It is for this reason that many consumers will prefer to buy this type of room humidity meter.
The design of the device consists of the following elements:
- metal box;
- rubber pear;
- thermal insulation strip;
- front wall;
A capacitor type of moisture and temperature meter analyzes the amount of condensate that forms on the surface of the glass. A small beam of light is directed to a special mirror that cools, as a result of which water droplets or ice crystals appear on the surface. The temperature is determined by an electronic thermometer embedded under the mirror. The device converts the data into an indicator showing the level of relative humidity.
Note! Consumers can choose and buy a device for measuring the humidity of the air with improved modifications. Such models are equipped with a display designed to display readings. The advantage of such devices lies in long-term stability. Devices are characterized by a long service life and an increased range of action (the device covers from 0 to 100%).
The capabilities of an electronic device for measuring the humidity of the air in a room make it possible to measure changes in the concentration of electrolyte with which the material with electrical insulating properties is coated. Such materials include plastic and glass. Some versions of the device have the function of automatic heating. They measure the dew point.
In addition, temperature fluctuations are taken into account, since it can affect the operation of the device, albeit insignificant, therefore devices are equipped with thermometers that facilitate their operation.
Electronic modifications are accurate in measurements, which mechanical structures cannot offer. The percentage of errors in their work is extremely low.
Consumers can buy air humidity meters that have different specifics of work:
- Air Conductivity Measurement — Devices determine the value of absolute humidity. To calculate the relative humidity is required to measure the temperature.
- Optoelectronic measurements – devices measure the dew point using a cooled mirror. It freezes, after which the process of its gradual heating takes place.
- Resistive measurements – the device is based on the effect of changing the conductivity of polymers or salts under the influence of humidity levels.
- Capacitive measurements – in the process of operation, the unit monitors the change in capacitance of the capacitor (polymer or metal oxide).
Psychrometers are designed to determine the relative humidity. The device operates due to the physical properties of the fluid, in particular, its ability to evaporate. In the process, there is a difference between the temperature readings of a wet and a dry thermometer. Liquid during the evaporation of the energy is lost, because of which there is a decrease in temperature. This change catches the thermometer.
The psychrometer design consists of a pair of alcohol or mercury psychrometers. During the evaporation of the liquid is cooled wet thermometer. The lower the humidity level, the faster the liquid evaporates. In turn, the drier the air, the lower the temperature index displayed by wet thermometers. Due to this, there is a difference between the readings.
Note! Regardless of how the device measures the humidity, it is not allowed to be installed near radiators or air conditioners, otherwise the measurements will be inaccurate. In addition, you need to monitor the state of the material for moisture. It should be clean and wet.
Some psychrometric hygrometers need certain temperature conditions. For example, the lowest permissible value for winter is -15 ° C; for summer, the highest temperature limit is 40 ° C. The measurement range depends on the temperature, the table of air humidity with environmental indicators can be used as a guide.
Measurement range according to the table of air humidity:
|Air temperature,? С||Permissible range,%|
|from 20 to 23||from 54 to 90|
|from 24 to 26||from 40 to 90|
|from 27 to 40||from 20 to 90|
The process of measuring humidity with a psychrometer is very simple. In addition to this value, the device also measures the temperature parameter. As a rule, together with alcohol thermometers mounted on a plastic base, the manufacturer places a psychrometric table of relative humidity, which allows you to read the readings.
There is one important condition that ensures accurate operation of the device. The psychrometer is extremely sensitive to drafts, therefore it is recommended to create conditions under which the speed of movement of air masses in a room should not be more than 1 m / s. Otherwise, the difference in readings taken from thermometers will be much more than in reality, which will result in inaccurate result.
Psychrometric table of air humidity is used to decipher the readings of the psychrometer. The first column contains the temperature readings of the dry thermometer. The first line displays the difference that occurs in the measurement process between the readings of both thermometers. To get the actual level of relative humidity, you need to take the value that is formed at the intersection of the corresponding parameter from the first column and the first row.
Assman’s psychrometer is an improved modification of the device that performs measurements more accurately and is not afraid of drafts, because its thermometers are protected from heat and direct sunlight due to the metal case.
Clients who pay increased attention to their own health and are seeking to bring air readings to the optimum value, manufacturers of climate technology offer to buy an electronic hygrometer – a humidity and temperature meter and a barometer in one device. A design with similar functionality is able to fully control the microclimate. However, the price of such devices is quite high.
Such devices not only have a large number of functions, but also have a decorative design. They can optimally fit into almost any interior room. There are also unusual combinations on offer, such as radio nannies with a built-in hygrometer. These devices are optimized specifically for children’s rooms. There are also models with Wi-Fi function. They connect to the World Wide Web and display a weather forecast and other data on the display.
The hygrometer will become an indispensable assistant in maintaining optimal climatic conditions in the house. Its readings help to correct the work of a humidifier or air dryer and bring the level of water vapor in the air to normal.