In meteorology the meteorological variables that determine the weather are continuously measured. The most important variables are atmospheric pressure, humidity, solar radiation, the direction and strength of the winds, etc. Each weather variable provides valuable information about the weather and allows you to predict what the weather will be in the next few days.
Today we are going to talk about hygrometer, the device used to measure humidity. Do you want to know how it works and everything related to the information it can provide in meteorology?
Main features, history and utilities
The hygrometer is nothing more than an instrument used to measure the degree of humidity in the air, soil and plants. We remember that humidity is the amount of water vapor in the environment. So that the humidity is saturated, the ambient temperature has to be lower. In this way, the water vapor in the air condenses and gives rise to dew.
The hygrometer is used to measure the amount of water vapor in the air. There are several types of hygrometers depending on their operation, although they all have the same purpose.
The hygrometer was invented by the French physicist Guillaume Amontos in 1687. It was later improved and optimized by Fahrenheit in the mid-XNUMXth century. It uses sensors that perceive and indicate the variation in the degree of humidity, both of a gas and of air in general. The oldest were built with mechanical type sensors. These sensors gave responses to elements sensitive to variations in humidity, such as human hair.
Its applications are very broad. They are used both for the conservation of products that are very vulnerable to excessive humidity, to know the proximity of possible rains and bad weather in general, to have good hygiene knowing the degree of humidity in the premises and rooms. It is also used in many industrial processes that require humidity, such as the manufacture of certain fabrics, paper, and silk.
Necessary concepts about humidity
To understand the correct operation of hygrometers, it is necessary to know some concepts of humidity and how it works.
For example, relative humidity It is a concept that many people are not clear about. Water vapor is generated through the different activities of human beings and, in general, of any living being. In homes, water vapor is generated through cooking activities in the kitchen, showers, perspiration from plants, respiration, etc.
This water vapor that is produced is absorbed by the air depending on the environmental conditions, causing an increase in the moisture content of the air. Therefore, the maximum amount of water vapor that can fit in the air without becoming saturated (that is, condensing) depends on the ambient temperature. The warmer the air, the more water vapor it can hold without becoming saturated with moisture. So that relative humidity is the amount of water vapor in the air in percent.
Another related concept is absolute humidity. It is the amount of water vapor that a cubic meter of air contains and is expressed in grams per cubic meter. Hygrometers are also capable of measuring the saturation point of the environment depending on the temperature. The saturation point is the maximum amount of water vapor that can be present in water at a certain temperature and pressure without the water vapor condensing.
The best hygrometer thermometers
If you would like to a good hygrometer, You can look at these recommended models so that relative humidity is not a mystery to you:
ThermoPro TP53 (pack of two)
It is a thermometer with hygrometer which has a large, backlit LCD screen to show values clearly. It will show both humidity and temperature in their high and low values, and will show an indicator of whether you are in the dry, comfort or humid zone based on the measured RH.
Its screen is touch and easy to use. It works with 2 AAA batteries that will last a long time, and can measure ranges from -50ºC to +70ºC and humidity between 10% and 99%, so it is suitable for almost any environment.
govee
It is a Govee model, it is another of the most modern, with a temperature and relative humidity sensor of the environment with great precision. A quality brand with bluetooth technology to monitor data from the mobile app. With a large LCD touch screen with blue lighting, maximum and minimum temperature meter, and relative humidity.
Shows the maximum and minimum temperature, humidity, other functions such as set to ºF or ºC. You can even import the recorded data to a file in CVS format to analyze it.
ThermoPro TP55
In appearance and features it is like the previous one from Amazon, only this ThermoPro TP55 is under the original brand. has a large 4” touch screen where you can see the maximum and minimum temperature, relative humidity, which comfort zone you are in, and it also works with 2 AAA batteries.
TFA Dostmann 30.5019
It is a very simple digital hydrograph thermometer, but practical. It has a round LCD screen that will show the current temperature, the HR and an indicator imitating an analog needle that will show which zone you are in: dry, comfort and humid. It has maximum and minimum memory, and can read ranges of 0-50ºC and 20-95% RH.
Bresser Professional Weather Station
This Weather Station It allows you to monitor temperature, humidity, wind, with a solar energy sensor for the exterior (UV radiation and ambient light meter), and a rain collector. With this, you will be able to monitor the weather forecast in real time. All on its large, easy-to-read color LCD screen.
It has WLAN technology, that is, it connects to a WiFi network to transmit data from external sensors and the monitor inside the home. The sensor connects to the console via RF (915 Mhz), and the console connects to the home router (2.4Ghz). In addition, thanks to the app you will be able to see data history, warnings and information through your mobile device.
Hygrometer types
Depending on the type of operation of the hygrometer and the characteristics they have, there are different types.
Hair hygrometer
This type of hygrometer it is known as hygroscope. Its operation is very basic. It consists of joining a group of hair grouped in the form of a cord. Hair responds to different changes in humidity that is registered in the air by twisting or untwisting. When this happens, a needle is activated that indicates the amount of humidity in the environment, but is not able to show it in percentages. Therefore, it is not able to measure relative humidity.
Absorption hygrometer
This type of hygrometer works by means of some hygroscopic chemical substances that have the ability to absorb or release humidity from the environment, depending on what there is. Hygroscopic substances are those that bind to the drops of water vapor and that are the ones that form the rain.
Electric hygrometer
It works with two spiral wound electrodes. Between the two electrodes there is a tissue that is impregnated in lithium chloride mixed with water. When alternating voltage is applied to the electrodes, the tissue is heated and some of the water that is mixed with the lithium chloride evaporates.
At each temperature it establishes a balance between the amount of water evaporates by heating the fabric and that which is absorbed by the humidity of the environment, since it is next to lithium chloride, a very hygroscopic material. As the situation changes, the degree of environmental humidity is established with greater precision.
Condensing hygrometer
This meter is used to determine the percentage of humidity in the air. To do this, it uses the temperature at which a polished surface tarnishes causing the temperature to be lowered artificially.
Digital hygrometers
They are the most modern that exist and use electronic circuits to convert the small voltage variations caused by the variation of some physical properties into numbers that are displayed on the screen. Some models of these hygrometers use some substances whose special property is that change color depending on the ambient humidity. With this they can obtain more precise humidity measurements.
As you can see, the hygrometer has many uses in meteorology and not only in it, but in the day-to-day life of many industries, homes and buildings. It is important to know the humidity and what better way than to use hygrometers to measure it.
What data does a hygrometer show and how to interpret it?
The data displayed by a hygrometer They are in percentages. That is, what relative humidity (RH) will measure is the relationship between the partial pressure of water vapor and the equilibrium vapor pressure of water at a given temperature.
Simply put, it will be the amount of water suspended in air. Even if you don't see it, there are large amounts of water in the air. In fact, some countries with drought, such as Australia, are using condensers to make that water fill tanks and thus obtain water from the air. It is also a very visual effect if you have a dehumidifier at home, as you will see how after hours of use, the multi-liter tank will fill up.
That said, the percentage is easy to interpret. A higher percentage means that the air and water mixture is wetter. For example, a 100% relative humidity It means that the air is saturated and is at its dew point, therefore, water may condense on walls or glass surfaces, such as what happens in the bathroom, on the windows when it is very cold outside, etc. By the way, this percentage can vary depending on the temperature as you can imagine, therefore, if the temperature is lower, that saturation point will reach sooner.
Depending on the temperature, people can feel comfortable and in good health between 30% and 70% RH, although ideal values are 50-60%. Below or above that could have consequences for your health, your pets, and the materials of devices (metals, electronic devices, furniture,...) and constructions.
Why do you have to control the humidity at home?
Humidity is a key factor for the conservation of equipment and your own health. Therefore, it is vital to have humidity under control at all times to extend the life of the equipment and to improve your health. Some of the problems arising from an inadequate humidity level are:
- With very low values you will notice dry skin, dry eyes or respiratory tract which could lead to other health problems. In very dry environments you should have an air humidifier.
- Above the ideal values it will especially affect your joints and respiratory system.. Especially if you have problems like arthritis, asthma, COPD, etc., it would be wise to have a dehumidifier.
- But high humidity will also affect your walls and ceilings, electronic devices, metals, etc., since it can generate humidity (fungus and mold, with an associated bad odor), small short circuits or deterioration of its parts, and oxidation respectively.
- Your clothes will also suffer, as they will become more damaged and may appear fungus or bad smell in your closets and shoe racks.
Types of humidity
The types of humidity that you can have in a home or walls of your business are:
Due to condensation
La humidity by condensation It is one in which the temperature differences of some surfaces cause the water to condense and generate small droplets, or when the temperature is so cold that it becomes saturated sooner. It is characterized by fog on the windows, mold stains on the walls, the appearance of fungus in some areas, deteriorated furniture, and unpleasant odors.
By capillarity
In the most humid and rainy areas water can leak from the underground up, especially damaging the walls in lower areas and basements. This humidity is difficult to remove, and you must apply certain chemical anti-humidity treatments that your trusted painter can advise you on. You should pay special attention if this type of humidity affects load-bearing walls or pillars, which could even compromise the structure of the building.
Due to infiltrations
The infiltrations They occur when water accumulates outside or there are pores or fissures that cause it to leak from the roof or through walls, joints between buildings, etc. This humidity penetrates the building's coating and has very similar symptoms to capillary humidity, and its treatment is also usually similar with anti-leakage or insulating treatments.
How to lower the humidity at home
Whatever type of humidity you experience in your home, you should know that there are some things you can do to reduce those dangerous levels. These are some methods:
Buy a dehumidifier
Buy a dehumidifier For home or industrial use, it is one of the ways to extract large quantities of water from the environment quickly and effectively. This can be practical for condensation damp. Additionally, you can obtain water from the air to water your plants (never to drink, since it is not treated).
You must know that there is dehumidifiers of all types and sizes, from household ones, to some small ones for cabinets or drawers, through industrial ones...
Open the windows
La ventilation is very important. A poorly ventilated house will accumulate more humidity inside. It is very evident when you enter a damp house, as it will have an unpleasant damp smell or have problems such as mold or mildew on certain surfaces.
You should ventilate each room at least 15 min a day. This will renew the air and avoid humidity problems.
Consult a professional
If you see that the paint is peeling off your walls, they have dark or black stains, there is mold or mildew on certain surfaces such as ceilings or low areas of walls, leaks, etc., it is preferable that you call an expert to evaluate the problem. Once the type and origin of your humidity has been identified, they will be able to apply a corrective treatment or make some recommendations.