You can, of course, buy a thermometer-hygrometer, but it is interesting and cheaper to make it yourself. In view of the excess of free temperature sensors and some other parts lying around idle, I decided to assemble this device that I need in everyday life on ATmega168V and SHT21. Read more on…
In the circuit, the sensor measures not only temperature, but also humidity. For me, the practical use of this feature is doubtful, but since it might come in handy for someone, I decided to use it as well. By the way, this is probably one of my longest projects (software was written for a month!). The development was delayed mainly due to lack of free time and the buggy of some compiler, from some company, but first things first…
The thermometer does not have any exotic features - it just shows the temperature with humidity and a battery charge indicator. The display of data takes place on the screen from the Siemens phone. I wrote about how to connect it to the microcontroller earlier (link at the end of the article). I chose this display as the most economical display I have and it is very thin and easy to control with a microcontroller. The only drawback: at a voltage below 2 volts, nothing can be disassembled on it (although the controller works stably even at 1.8 V). That is why when the battery is discharged to about 2 volts, the battery indicator will be displayed on the screen.
I took the time to draw (or rather copy!) Big beautiful numbers to display the temperature and small strict numbers to display the humidity. What came out of it is clearly visible in the pictures.
Printed circuit board? No, have not heard:-). Yes, and why is she here if the details are one, two, and miscalculated. good installation+ high-quality case and nothing to this device is not scary. Moreover, I do not plan to play football with them. All parts are connected with MGTF f-0.07 mm wire - the best mounting wire in the world :). Only it is difficult to clean it, but this is just its only minus. I don’t have any battery holder (due to the limited space in the case), so the wires were soldered directly. I used soldering acid as a flux, because I didn’t want to solder with rosin at a relatively low temperature of the soldering iron, and I didn’t dare to overheat the battery. All exposed contacts were carefully insulated with tape before shoving the whole thing into the case. I bit off the extra legs of the controller (with the exception of those that are needed for the firmware), and the case itself was glued with superglue. The display, by the way, also rests on it. As a result, the device looks much more beautiful from the outside than from the inside 🙂 It is also important not to forget to make a hole in the case for the sensor if we want to measure the temperature not inside the device case. The case itself is called G1906 (~$2), and this is how it looked at the very beginning of my mockery of it:
The most difficult thing here is to do just such a rectangular hole. I did this: first drawing a rectangle and then making holes along the contour conventional drill which I drill boards. After drilling 100500 holes, the rectangle breaks out, and the edges are cleaned with a file. By the way, this is perhaps the most even hole of all that I have ever done 🙂
Everything is quite simple and trite, except for a small highlight of power management. I spied it in some magazine: We close the button, the device starts, sets a logical unit on the leg, thereby maintaining the transistor in the open state, and after five seconds a logical zero appears on the leg and the transistor closes, cutting off the power of the entire device. Everything is ingenious and simple. Before use, you need to twist the resistor R4 so that at three volts of the supply voltage, a voltage of 1.1 volts is present on its brush connected to PC0. Otherwise, the charge level will not be displayed correctly. It is best to use a multi-turn resistor, it is easier for them to adjust tenths of a volt. The microcontroller operates at a frequency of 8 MHz from an internal oscillator. In total, the device consumes 5 mA, which means that the batteries (CR2032) will last for a long time.
And now we got to the most interesting part of the project: the software. Taking this opportunity, I would like to pour tons of hatred on the creators of the micropascal compiler. I have never seen such curvature. After my program began to occupy more than ~ 10kb of flash memory, inexplicable glitches began, which I skillfully overcame by stuffing various crutches. In my program, you can find unnecessary UART initialization (it doesn’t work without it), port settings through assembler inserts, and some other interesting things! I no longer write in micropascal, which is what I wish you.
Ready-made thermometers and thermometer-hygrometers can be bought, for example, here:
SHARE WITH FRIENDS
P O P U L I R N O E:
Recently, an old friend came to us. He lives in a private house and a couple of times unknown persons tried to visit him without an invitation. There is a need to install an alarm system. It turned out to be too expensive to put the house on the remote control. The best solution seemed to be to simply notify the owner with a call to the mobile phone when one of the motion sensors is triggered.
Air humidity level environment can affect not only the well-being of a person, but also the state of household appliances, furniture and products. The amount of moisture in the air depends on the climate of the region or man-made factors.
The norm for a healthy person is considered to be air humidity from 30 to 60%. To create an optimal microclimate in the room, special humidifiers or dehumidifiers are used, as well as air conditioners with automatic humidity control functions.
Use special instruments to measure:
- hygrometers;
- psychrometers.
A hygrometer is one of the measuring instruments, thanks to which you can determine the level of humidity.
Additional information: In 1783, the Swiss scientist Horace de Saussure designed the first hair hygrometer, but Leonardo da Vinci began working on the invention of this meter as early as 1400.
There are several types of hygrometers:
- hairline;
- weight;
- condensation;
- electronic;
- electrolytic;
- film;
- ceramic.
Each of the devices has a special principle of operation. For example, the design of a hair hygrometer is a system of U - shaped tubes. They are filled with a special substance that absorbs water vapor. Air is pumped through this system by means of a pump and its humidity is determined.
The most accurate meter is considered to be a condensation hygrometer. It measures the amount of condensation that forms on a glass surface after being exposed to sunlight. The error in the operation of such a device is very low.
A psychrometer is another of the environmental humidity meters.
Types of psychrometers:
- August psychrometer (station);
- Assmann psychrometer (aspiration);
- remote psychrometer.
The August psychrometer is one of the most well-known instruments for measuring humidity. The structure of this structure is quite simple. The design of the psychrometer consists of two identical thermometers attached to one stand. One of them is called dry, it shows the temperature in the room.
The second thermometer is called wet or wetted. The end of this thermometer in the form of a cover is wrapped with batiste cloth or gauze, the end of which is lowered into a reservoir of water located on the back of the psychrometer.
If the end of a wet bulb bulb is dipped into a tank, it will indicate the temperature of the water there, not the air that circulates above it. Therefore, it must be taken into account that the distance between the vessel and the end of the measuring device should be about 3 - 4 centimeters.
The water on the piece of cloth evaporates, causing the temperature on the wet bulb to drop until the thermometer starts to show the temperature at which the steam becomes saturated. At this point, the data displayed on the wet bulb will represent the actual ambient temperature.
Determination of air humidity in a certain room using a psychrometer takes a little time. To do this, the device is placed in a place isolated from sunlight and extraneous thermal influences for 10-15 minutes, after which the measurement results of each of the device's thermometers are recorded.
The thermometer scale is divided from - 25˚ to + 50˚ into intervals of 0.2 degrees.
How to use the psychrometric table
To determine the level of humidity based on psychrometer data, a special psychometric table is needed. The first column of the table shows the dry bulb temperature in ˚C. In the first line - the difference between the temperature readings of both thermometers. Relative air humidity is calculated at the intersection of the result of the first column and the first row of the psychometric table.
What are the pros and cons of a psychrometer?
The main advantage of the psychrometer is its simple structure. Accordingly, the determination of air humidity with a psychrometer is much easier compared to other measuring devices. Plus, it is much cheaper to manufacture than any other device.
But besides the positive aspects, the psychrometer also has disadvantages. The readings of this measuring instrument are greatly influenced by the movement of the surrounding air. That is, the higher the air velocity at the measurement site, the greater the difference in the final result of both thermometers of the psychrometer. This error was corrected in the aspiration-type psychrometer or, as it is also called, the Assmann psychrometer.
What is the peculiarity of the Assmann psychrometer?
The Assmann psychrometer is a much more complex and more reliable device for measuring air humidity. Both thermometers of the design are located at the lower ends in a special metal case, which protects them from sunlight, thermal effects, as well as from various damage. The air moves at a constant speed due to the operation of the fan. This fan, also known as an aspirator, blows the thermometers at a speed of 2 m/s.
Determination of humidity using this psychrometer: the device is suspended at the place of study at a height of 1.5 m from the floor; results are obtained in 10-15 minutes in winter and 4-5 minutes in summer.
The August psychrometer and the Assmann psychrometer have in common that both contain glass-mercury thermometers. The disadvantage of these devices is their fragility and, accordingly, the inability to carry out measurements remotely.
What is the difference between a remote psychrometer and other devices
A remote psychrometer is another example of a humidity measuring device. The design of this measuring device uses electronic devices such as a resistance thermometer or thermistors.
The main types of remote psychrometers:
- manometric;
- electrical.
A manometric psychrometer consists of one or two manometric type thermometers. In electronic psychrometers, as in all other remote meters, silicon transistors are used, which replace the sensors of dry and wet bulbs.
What is the difference between a psychrometer and a hygrometer
The main difference between these devices for determining humidity is the principle of their operation. The function of the hygrometer is to measure not only the humidity of the air, but also the humidity of various solids.
The indicators of a psychrometer, despite the simplicity of its design, are always more reliable, which is why in the notes to the instructions of some hygrometers it is recommended to check the readings on a psychrometer.
How to find out air humidity without measuring instruments
To conduct this experiment, you will need an ordinary glass, some water and a refrigerator. A glass with cold water. When the temperature of the liquid in the vessel reaches 3 - 5 ° C, the glass is placed in a room where air humidity will be measured.
If the air in the room is very dry, then condensation will be observed on the surface of the glass, which will disappear after 5 to 10 minutes of observation. If the air in the room is very humid, then large drops of condensate form on the walls of the glass within 5 to 10 minutes. If none of the two previous options is observed, the air in the room is of medium humidity.
How to make a do-it-yourself air humidity meter
The psychrometer is a fairly simple invention in its design, so anyone can make it on their own.
Necessary materials:
- two alcohol thermometers;
- a small piece of batiste fabric;
- several wooden slats;
- small screws;
- glass jar.
To stand the psychrometer, you need to take a small wooden plate measuring 50mm wide and 120mm long. We attach a rail to it with screws, the length of which depends on the length of the measuring instruments used. Another bar is attached perpendicular to it, on which thermometers will be held.
For compactness and highest accuracy of indicators, thermometers should not be placed at a great distance from each other.
The base of the device can be connected to the stand by drilling a small hole in it, or you can use PVA glue. After the body of the psychrometer is assembled, the lower bulb of one of the thermometers is wrapped with a batiste cloth. The end of the fabric is lowered into a vessel containing a non-freezing liquid.
When checking the indicators of a manufactured device, you should check the results of the factory meter and compare both indicators. In the future, to determine the level of air humidity, it is necessary to use a special psychrometric table.
Using a minimum of materials and free time, the owner finished product will receive useful tool to measure the level of moisture in the air.
Novice poultry farmers may not think that it is necessary to control not only the air temperature in the incubator, but also its humidity. In this case, it should be borne in mind that during different periods of incubation, the readings of the moisture meter will differ from each other. So, at the very beginning, air humidity should be maintained at a level of 65-75%, in the middle of the period it must be reduced to 40-50%, and at the withdrawal stage - 75%. Such a multi-stage approach will improve the hatchability of eggs several times over.
How to measure humidity in an incubator?
You can measure the humidity in the hatching box by using a special device called a hygrometer. The most common model can measure humidity that is in the range of 20 to 99%, while the error is only 5%, which cannot have a detrimental effect on the development of future offspring.
Most electronic devices designed to measure humidity in an incubator are equipped with a special sensor that is attached to a wire. This allows you to take measurements inside the case. At the same time, you can control the level of moisture by the scoreboard placed outside. It displays not only the percentage of humidity in working area, but also the approximate temperature.
The ease of use of the hygrometer is particularly important. It is equipped with a switch that has two working positions: "on" / "off". It also has several buttons that switch temperature units. What a hygrometer looks like, you can see in the photo.
Humidity meters designed for home poultry breeding are relatively inexpensive. Its average price is from 500 to 1000 rubles per unit.
How does a hygrometer work?
To measure the air humidity inside the incubator, it is necessary to lower the sensor inside it through a specially made hole as shown in the photo. Fix it in limbo for 5-7 minutes. After that, the desired humidity indicators will appear on the display.
If you still had to open the lid of the incubator, then the real readings will be ready only after 40-60 minutes.
How to use the electronic hygrometer correctly?
In order for the device to work properly for many years, it is necessary to protect it from mechanical influences, in particular from shocks and pulls on the wire on which the sensor is attached.
Do not place the hatcher, and therefore the moisture meter, under the sun and in a draft. This may provide Negative influence for future breeding.
An important condition for the normal functioning of the device - temperature regime, which can vary from -40 to +70⁰С.
Keep the hygrometer away from liquid, dust and dirt. Particular care must be taken with the sensors and housing.
What to look for when buying a hygrometer for hatching chicks at home?
Before purchasing a device for measuring air humidity in an incubator, it is necessary to study specifications all products on the market.
- Pay attention to the measured pressure parameter. It can be relative (RH) and absolute (g/m3).
- Consider in advance how many eggs will fit in the trays. Having decided on this indicator, tell the sales assistant about it, and he will help you make the right choice.
- If you need a device with high measurement accuracy, then give preference to optical devices.
- If you plan to place the device outside the living space, pay attention to the degree of its protection. It is measured, as a rule, on the IP scale. The values of this scale indicate the degree of reliability and the level of resistance of the device to water, dust and dirt.
As noted, the standard temperature regime of the hygrometer is -40 to +70⁰С. However, if you are going to operate it in other conditions, carefully study this indicator. Otherwise, you will not get the desired result - the chicks simply will not be able to hatch.
Is there an alternative to an electronic moisture meter in an incubator?
Despite the fact that a ready-made device for measuring humidity is not so expensive, some poultry farmers recommend making a device designed for the same purpose on their own. They explain this by the fact that the devices used for homemade hygrometer give more accurate readings than their electronic counterparts.
How to make a homemade device:
- To do this, you will need two ordinary mercury thermometer, which measure the temperature of the air, board and water.
- Thermometers are fixed along the edges of the board so that they are parallel to each other, and a container with distilled water is placed under one.
- We wrap the mercury ball with a cotton cloth and tie it with a thread not very tightly.
- We lower the edges of the fabric into the water by about 5 millimeters.
- The indicators recorded by thermometers are compared with each other and compared with specially designed tabular data that are given in the description of psychrometers. For example, if the dry bulb reading is 37.5 degrees and the wet bulb reading is 26 degrees, then the relative humidity in the hatcher is 38%. Thus, the humidity of the air in the incubator is calculated.
Thus, the success of the hatching process is affected not only by the level of air temperature, but also by its humidity. The latter can be measured with a special device - a hygrometer, which can be bought at any pet store or made by yourself. However, the second option is rather laborious.
Special moisture meters are used. To date, there are needle, contact and chip modifications. In terms of parameters, they are quite different. However, there are not many manufacturers on the market for moisture meters. The main companies include EMSO and Valcom. There is an average good moisture meter on the market in the region of 1500 rubles.
How to do it yourself?
If necessary, you can make a moisture meter for wood with your own hands. Its circuit includes a dielcometric type sensor. Also, the device will require a compact generator. Its limiting frequency parameter must be no more than 30 MHz. Contacts for homemade model it is more expedient to select needle-shaped ones. Also, to make a moisture meter for wood with your own hands, you will need a three-channel type chip.
The device should be in the region of 3.5 f/m. The microprocessor for the model is selected with a pulse amplifier. Probes are most often used tubular type. The display is more expedient to select lowercase. Compared to text counterparts, it is simpler. Capacitive electrodes are used directly in moisture meters. In turn, the catcher will need to be installed resistive. Batteries are selected last for the model. In this case, you can use ordinary finger batteries.
contact models
Contact moisture meters for wood are well suited for working with plywood, as well as parquet. Additionally, in the construction industry, devices are used to determine the moisture content of panels. If we talk about contract features, then low-frequency generators are used in the devices. Directly the probes are installed tubular type.
The dielectric constant of most moisture meters does not exceed 3 F/m. Maximum temperature models of this type are able to hold at 40 degrees. The display is used as a line and text type. Many modifications are equipped with temperature sensors. The calibration function is available on many devices. It costs an average of a high-quality moisture meter in the region of 2 thousand rubles.
Needle moisture meters
Needle moisture meters for wood are used, as a rule, for pine or spruce. The sensors in all configurations are of the dielectric type. If we talk about the parameters, then the measurement accuracy mainly fluctuates around 0.2%. The maximum humidity threshold of devices does not exceed 35%. Minimum allowable temperature for models is 0 degrees. Microprocessors in many devices are used with amplifiers. There is an average moisture meter for wood (needle) in the region of 1200 rubles.
Probe devices
Probe moisture meters for wood are mainly manufactured by the Valcom company. If you believe the opinion of experts, then their parameter is extremely low. Generators in devices are used with a frequency of 20 MHz. Directly traps are installed resistive type. The minimum moisture threshold for models does not exceed 5%. In turn, the devices are at level 1 PH. Displays are often used in moisture meters line type. Some modifications are equipped with thermometers. The calibration function in devices is quite rare. You can find a model of this type on the market for 2 thousand rubles.
Model EMCO AP
In the construction industry, the presented moisture meter is in great demand. It is ideal for working with parquets and panels. Also, this moisture meter is equipped with a thermometer. Another advantage of the modification can be safely called the presence of needle-type contacts. The manufacturer provides a three-channel microcircuit for the model, so the measurement of wood moisture is fast. The electrodes are capacitive type.
The maximum humidity threshold does not exceed 40%. In terms of dimensions, the specified moisture meter is very compact, and belongs to the class of portable devices. According to the documentation, its mass without batteries is 80 g. The resolution of the model is at the level of 1.3 pH. The maximum allowable temperature of the model is exactly 35 degrees. It is forbidden to use the presented device in frost. The measurement accuracy fluctuates around 1.4%. In shops this device can be found for 2100 rubles.
Devices for determining moisture EMCO MP500
This moisture meter is equipped with a dielcometric type sensor. According to customer reviews, the resolution of the device is quite high. Directly the generator of the model is used at 22 MHz. According to the documentation, the maximum allowable temperature is 40 degrees. The display in the device is of the text type.
Batteries are used for 1 mAh, so they last a long time. In this case, the manufacturer provides a catcher of a resistive type. If you believe the reviews of experts, then there are no problems with determining the importance of chips. The maximum measuring depth is 10 mm. The user can purchase the presented moisture meter for 1400 rubles.
Model "Valkom EM4806"
The specified moisture meter for hardwood, among other models, is distinguished by a high resolution parameter at the level of 1.3 pH. All this suggests that the device works perfectly at temperatures below 10 degrees. In this case, the measurement accuracy indicator is at around 0.2%. The maximum allowable humidity threshold is 30%.
The catcher in the device is provided of a resistive type. The microcircuit is used three-channel, and the generator is set to low-frequency. According to the documentation for the device, the case is provided with the IP 62 protection system. The presented model weighs exactly 80 g. The moisture meter memory is enough for 30 thousand measurements. The user can buy it for 1500 rubles.
Ludmila Dudoladova
For our meteorological site, we decided to make a Christmas tree with cones. After all, an ordinary cone can turn into a unique device for weather forecasting.
The fact is that cones tend to close or open, depending on air humidity. When it's dry outside "revealed" so that the wind can spread its seeds and scatter as far as possible from the cone. And on the eve of rain or snow, when air humidity rises, the cone is usually closed to keep the seeds until a more convenient time, since it is easier for the wind to carry them dry.
So we decided to make a Christmas tree with cones to monitor the weather at our weather site.
A Christmas tree was cut out of plywood, sanded, painted in green color (the Dokuchaev family, Alina and Arseniy helped us with this)
With the help of decorative buttons and strong threads, cones were attached to the Christmas tree.
Now we look forward to the rain when the scales close showing that air humidity has increased.
A pine cone is a unique phenomenon in nature, it only needs to be learned how to use it. I hope that as a result of observing the cones, children will understand why they open and close.
Children must come to the conclusion that the cone is nature's weather forecaster.
Related publications:
Play is a natural activity for a child. It is the game that makes it possible to acquire new knowledge about the world around us, to broaden our horizons.
How much has become Lately include foreign words in the everyday life of our speech! It doesn't matter what industry it is. The fact remains.
Do-it-yourself business board! Dear colleagues, thank you for paying attention to the manual I made - the business board. What is a business board? Business board.
Dear colleagues! I present to your attention a do-it-yourself board-board. Meet this girl Cleopina.
Photo props are made from thick paper or cardboard analogue of any object. It can be glasses, mustaches, lips, hats, funny.
The game is one of the most important activities of a preschooler, during which the appropriation of experience and adaptation to the environment takes place.
Do-it-yourself carpet maker. Carpet recorder "Larchik" is a unique manual by Vyacheslav Voskobovich, a well-known manufacturer of educational toys. Carpet graph.
Today, much attention is paid to the level of humidity in residential premises. Many mistakenly believe that this indicator is actually not so important, as manufacturers of humidifiers make it out to be.
But if you look into it in detail, the level of humidity in the environment actually has a huge impact on our well-being.
Normally, the humidity level in the house ranges from 30 to 60%, but in winter time the air dries up, and in the summer, as a rule, this figure is higher than normal.
Dry air is the main reason that our mucous membranes and skin suffer from a lack of moisture and a decrease in immunity, fatigue and drowsiness occur.
And in general, the well-being of people with reduced humidity is far from ideal. However, even this is not the worst! Excessively dry air can cause chronic rhinitis, allergies and even asthma.
Children and people suffering from various chronic diseases are especially sensitive to changes in air humidity.
Needless to say, even the premises themselves suffer from an excess or lack of moisture in the air. So, for example, with excessive moisture content, mold fungi settle on the walls of the house and there is bad smell dampness.
With excessive dryness of the air, they quickly lose their appearance all pieces of furniture made of wood and parquet. Cracks may appear on them, indicating their drying out.
Device for measuring the level of air humidity
Therefore, every home should have a device that measures this important indicator. One of the simplest and available species devices that allow you to control the level of humidity, is considered to be a hair hygrometer. It is easy to use, but at the same time allows you to get the most accurate data.
Design features of the device
It has a fairly simple design. It consists of a metal frame with skimmed synthetic or natural hair stretched over it.
A small load is attached to the free lower end of the hair, in addition, it is thrown over a pulley and connected to an arrow that moves freely along a scale on which the relative humidity of the air is indicated as a percentage.
When the air humidity changes, the arrow moves along the scale and shows us its current level.
Operating principle
The principle of operation of the device is based on the ability of a hair to change its length in a humid environment. With a decrease in this parameter, the hair becomes shorter, and with an increase, on the contrary, it becomes longer.
When changing the length of the hair, the pulley turns and moves the arrow along the scale showing the level relative humidity environment. Each division of the hygroscope scale corresponds to 1% relative humidity.
Features of use
Hair can be either hung on the wall or installed, for example, on bookshelf. When choosing a place to install the device, you must pay attention to the fact that it should not be located in close proximity to sources of cold or heat.
It is equally important that there is no vibration at the place of installation of the device, that is, it is not necessary to install the device from above on any working electrical appliances.
Also, due to the fact that the principle of operation of the device is based on changing the length of the hair, it is not recommended to transfer it from place to place, subject it to sharp shocks and shocks, as this can cause the device to fail.
However, in order to have a hygrometer at home, it is not at all necessary to buy it, since this device can simply be made independently.
DIY hygrometer
In fact, making this device is much easier than it might seem at first glance.
It is necessary to take human or horse fat-free hair at least 40 cm in length. At one end of the hair, you need to install a small weight.
A washed ballpoint pen or the sharp end of a nail is ideal for this purpose. It is very important that the weight of the load is sufficient to completely straighten the hair. To attach the weight to the end of the hair, it is recommended to use nitro glue.
After that you need to take small size nail and put on it any plastic tube, no more than 5 mm long. It is necessary that the tube rotates as freely as possible on the rod and at the same time does not slip off it.
The hygrometer must be mounted on a vertical base or on a piece of plywood with a horizontal stand that serves as the base for the structure.
Now it is necessary to drive a nail with a plastic tube put on it in the center of the board equipped with a horizontal stand so that the edge of the hair thrown over it can be fixed with its free end on a horizontal base.
It is very important that the part of the hair thrown over the nail is equal to at least a third of the total length. The hair must be thrown over the nail, after which its free end is fixed with glue.
When the humidity level changes, the length of the hair will change accordingly, during which the tip of the plumb line will rise and fall. After that, it remains only to make a scale out of paper, which is then glued on the back of the plumb line.
As you can see, making a hygrometer with your own hands is a simple task. The main thing is to choose the right source materials for its implementation.
Fabricate and install on a high pole vane and tell the children how to determine the direction of the wind. Take a smooth stick and drive a long nail into one of its ends. Cut a flag out of thick cardboard and laminate it so that it does not get wet in the rain.
Wrap the edge of the flag around the nail so that it can rotate freely when the wind blows. Make arrows from thin wires pointing south, north, west and east and fix them on a stick. The weathervane is ready. Install it on your meteorological site, orienting the arrows to the cardinal points.
With older children (6–9 years old), making weathercocks fits perfectly into geography lessons when you tell how winds are formed, how the first sailors used knowledge about them, what winds mean at “horse latitudes”, what are trade winds.
Sailors, knowing about the trade winds - steady winds blowing in tropical zones - called them "trade winds", because with their help merchant sailing ships (engines had not yet been invented) crossed the Atlantic Ocean. Sailboats carried goods from Europe to America.
Subtropical winds between 30 and 38 parallels of the southern and northern latitudes were so light that the sailboats got up in the calm. I had to wait months for the right wind. Often the waiting was delayed for 3-5 months. The sailors were running out fresh water and food, and they had to subsist on horses, which were transported in large numbers from Europe. Therefore, these latitudes were called "horse".
Using a weather vane, children mark the direction, strength and change of the wind on their weather observation calendars. Thus, we not only introduce them to the main meteorological instruments, but also to the methods and techniques of observations and processing of results.
DIY thermometer
Install on a large weather site thermometer and teach children to read air temperatures. This work is also a preparation for understanding the concept of negative numbers in mathematics, which is offered to children 9-12 years old at the Montessori school.
Kids 3-6 years old will be happy to make their own thermometers from cardboard and colored threads. For this:
- In the middle of a white strip of cardboard 4–6 cm wide, a thermometer scale is applied (above and below zero).
- Connect together the red and blue (white) threads.
- Holes are made at the upper and lower ends of the scale and the ends of the threads are passed through them, tying them on the reverse side.
Referring to a real thermometer, the guys move the thread on their homemade thermometers, setting and recording temperatures on weather calendars.
DIY hygrometer
The next device of the children's weather station is hygrometer- a device for measuring air humidity. To make a hygrometer you will need:
- a rectangular piece of wooden plank or foam;
- two pushpins;
- scotch;
- human hair about 10 cm long;
- piece of thin wire.
Fasten two buttons on the board at a distance of about 8–10 cm. Attach the wire to the bottom so that it can move, that is, not tight. Attach the tip of the hair to the top button, then pull it around the wire and secure it to the top button. The device is ready.
Tell the children how human hair reacts to air humidity by getting shorter or longer. At high humidity, it will lengthen, thus lowering the arrow down; at low humidity, on the contrary, the hair will become shorter and raise the wire arrow up. This property of the hair is used to make a hygrometer.
Do-it-yourself rain gauge
Complement your weather site rain gauge- a device for measuring liquid and solid precipitation (hail). Take an ordinary bucket, install it on a small hill (pedestal, stool). Accumulated precipitation merges into a measuring cup with a scale. The children record the results on their calendars.
A do-it-yourself weather station is not only part of a subject-developing Montessori environment, but also a fascinating and informative opportunity to observe the weather and keep a journal of observations.
By discussing the weather with children, you can expand the topic and tell them about modern professions that depend on weather conditions. With older children (8-9 years old), as part of a Montessori program in economic geography, we talk about how climate conditions generally affect the economy of different countries.
