You can, of course, buy a thermometer-hygrometer, but it’s interesting and cheaper to make one yourself. In view of the excess of free thermal sensors and some other parts lying around idle, I decided to assemble this device needed in everyday life on the ATmega168V and SHT21. Read on for more details...
In the circuit, the sensor measures not only temperature, but also humidity. For me, the practical benefit of this feature is doubtful, but since it might be useful to someone, I decided to use it too. By the way, this is probably one of my longest projects (the software took a month to write!). Development was delayed mainly due to lack of free time and the buggy nature of some compiler from some company, but first things first...
The thermometer does not have any exotic capabilities - it simply shows temperature with humidity and a battery charge indicator. The data is displayed on the screen of a Siemens phone. I wrote earlier about how to connect it to a microcontroller (link at the end of the article). I chose this display as the most economical of all the ones I have + it is very thin and easy to control using a microcontroller. The only drawback: at a voltage below 2 volts, you can’t make out anything on it (although the controller works stably even at 1.8 V). That is why, when the battery is discharged to approximately 2 volts, a full battery indicator will be shown on the screen.
I took the time to draw (or rather sketch!) large beautiful numbers to display temperature and small, strict numbers to display humidity. What came out of this is clearly visible in the pictures.
Printed circuit board? No, have not heard:-). And why is she here if the details are missing once or twice. Good installation+ high-quality body and nothing is scary for this device. Moreover, I don’t plan to play football with them. All parts are connected with MGTF wire f-0.07 mm - the best installation wire in the world :). It’s just a little difficult to clean, but that’s just its only downside. I do not have any holder for the battery (due to 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 the relatively low temperature of the soldering iron, and I didn’t dare overheat the battery. All open contacts were carefully insulated with tape before putting the whole thing into the case. I bit off the extra legs of the controller (with the exception of those needed for firmware), and glued the body itself with superglue. By the way, the display also rests on it. As a result, the outside of the device looks much more beautiful than the inside :) It is also important not to forget to make a hole in the housing for the sensor if we want to measure the temperature outside the device’s body. The case itself is called G1906 (~$2), and this is what it looked like at the very beginning of my mockery of it:
The most difficult thing here is to make a rectangular hole like this. I did this: first I drew a rectangle and then I made holes along the contour with a regular drill which I drill boards with. After drilling 100500 holes, the rectangle is broken out and the edges are cleaned with a file. By the way, this is probably the smoothest hole I’ve ever made :)
Everything is quite simple and banal except for the small highlight of power management. I saw it in some magazine: We close the button, the device starts, sets a logical one 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 to 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 there is a voltage of 1.1 volts 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 a long time.
And now we get to the most interesting part of the project: the software. Taking this opportunity, I would like to pour out tons of hatred on the creators of the micropascal compiler. I have never seen such curvature before. After my program began to take up more than ~10kb of flash memory, inexplicable glitches began, which I skillfully overcame by cramming in various crutches. In my program you can find the unnecessary UART initialization (it doesn’t work without it), setting up ports through assembler inserts, as well as some other interesting things! I no longer write in micropascals, which is what I wish for you.
Ready-made thermometers and thermometer-hygrometers can be purchased, for example, here:
SHARE WITH YOUR FRIENDS
P O P U L A R N O E:
The other day an old friend contacted 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. It seemed like the optimal solution was to simply notify the owner with a call to his mobile phone when one of the motion sensors was triggered.
Humidity level environment can affect not only a person’s well-being, but also the condition 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 indoor microclimate, special humidifiers or dehumidifiers are used, as well as air conditioners with automatic moisture level control functions.
Use special instruments to measure:
- hygrometers;
- psychrometers.
A hygrometer is one of the measuring instruments that can be used to determine the level of humidity.
Additional information: Swiss scientist in 1783 Horace de Saussure designed the first hair hygrometer, but Leonardo da Vinci began working on the invention of this meter back in 1400.
There are several types of hygrometers:
- hairline;
- weight;
- condensation;
- electronic;
- electrolytic;
- film;
- ceramic.
Each of the devices has a special operating principle. For example, the design of a hair hygrometer is made up of a system of U-shaped tubes. They are filled with a special substance that absorbs water vapor. Using a pump, air is supplied through this system and its humidity is determined.
The most accurate measurement is a condensation hygrometer. It measures the amount of condensation that forms on a glass surface after it is exposed to sunlight. The operating error of such a device is very low.
A psychrometer is another measure of ambient air humidity.
Types of psychrometers:
- August psychrometer (station);
- Assmann psychrometer (aspiration);
- remote psychrometer.
The August Psychrometer is one of the most famous 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 a wet or wet thermometer. The end of this thermometer in the form of a cover is wrapped with cambric cloth or gauze, the end of which is lowered into a reservoir of water located on the back side of the psychrometer structure.
If the end of a wet bulb thermometer is lowered into a tank, it will indicate the temperature of the water there, not the temperature of the air that circulates above it. Therefore, it is necessary to take 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 wet bulb temperature to drop until the thermometer reads the temperature at which steam becomes saturated. At this point, the wet bulb reading will represent the actual ambient temperature.
Determining 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 contact with sun rays and extraneous thermal influences for 10 - 15 minutes, after which the measurement results of each of the thermometers of the device are recorded.
The thermometer scale is divided from - 25˚ to + 50˚ into intervals of 0.2 degrees.
How to use a psychrometric chart
To determine the humidity level based on psychrometer data, a special psychometric table is needed. The first column of the table shows the dry bulb temperature in ˚C. The first line shows 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, determining air humidity using a psychrometer is much simpler 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 speed at the measurement location, the greater the difference in the final result of both psychrometer thermometers. This error was corrected in an aspiration-type psychrometer or, as it is also called, an Assmann psychrometer.
What is special about 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 with their lower ends in a special metal case, which protects them from sunlight, thermal influences, and also from various damages. 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/sec.
Determination of humidity using this psychrometer: the device is suspended at the test site at a height of 1.5 m from the floor; results are obtained after 10 - 15 minutes in winter and after 4 - 5 minutes in summer.
What the August psychrometer and Assmann psychrometer have in common is that both have glass-mercury thermometers in their design. The disadvantage of these devices is their fragility and, accordingly, the inability to carry out measurements remotely.
How does a remote psychrometer differ from other devices?
A remote psychrometer is another example of a device for measuring humidity. The design of this measuring device uses electronic devices such as a resistance thermometer or thermistors.
Main types of remote psychrometers:
- manometric;
- electric.
A manometric psychrometer is one or two manometric type thermometers. Electronic psychrometers, like all other remote meters, use silicon transistors that replace dry and wet bulb sensors.
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 functions of a hygrometer include measuring not only air humidity, but also the humidity of various solids.
The readings of a psychrometer, despite the simplicity of its design, are always more reliable, which is why the notes to the instructions of some hygrometers recommend checking the readings using a psychrometer.
How to find out air humidity without measuring instruments
To carry out this experiment, you will need a regular glass, some water and a refrigerator. Place a glass of water in the refrigerator for several hours. cold water. When the temperature of the liquid in the vessel reaches 3–5˚С, the glass is placed in the 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 - 10 minutes of observation. If the air in the room is very humid, then large drops of condensation form on the walls of the glass within 5–10 minutes. If none of the two previous options are observed, the air in the room is of medium humidity.
How to make an air humidity meter with your own hands
A psychrometer is a fairly simple invention in its design, so anyone can make it themselves.
Necessary materials:
- two alcohol thermometers;
- a small piece of cambric fabric;
- several wooden slats;
- small screws;
- glass jar.
For the psychrometer stand, you need to take a small wooden plate measuring 50 mm wide and 120 mm long. We attach a strip 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 the thermometers will be held.
For compactness and highest accuracy of indicators, thermometers should not be placed at a large 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 psychrometer body is assembled, the lower balloon of one of the thermometers is wrapped with cambric fabric. The end of the fabric is lowered into a vessel containing a non-freezing liquid.
When checking the performance 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 air moisture levels.
Novice poultry farmers may not think about the fact that it is necessary to control not only the air temperature in the incubator, but also its humidity. It should be taken into account that during different periods of incubation the moisture meter readings will differ from each other. So, at the very beginning, air humidity should be maintained at 65-75%, in the middle of the period it should be reduced to 40-50%, and at the hatching stage - 75%. This multi-stage approach will improve the hatchability of eggs several times.
How to measure humidity in an incubator?
You can measure the air humidity in the hatching box by using a special device called a hygrometer. The most common model can measure humidity, which ranges from 20 to 99%, with an error of 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 measurements to be taken inside the housing. At the same time, you can control the moisture level using a display placed outside. It displays not only the percentage of humidity in work area, but also the approximate temperature.
Particularly noteworthy is the ease of operation of the hygrometer. It is equipped with a switch that has two operating positions: “on”/“off”. It also has several buttons that switch temperature units. You can see what a hygrometer looks like in the photo.
Instruments for measuring humidity intended for home poultry breeding are relatively inexpensive. Its average price ranges from 500 to 1000 rubles per unit of product.
How does a hygrometer work?
To measure the air humidity inside the incubator, you need to lower the sensor inside it through a specially made hole as shown in the photo. Fix it in a suspended state for 5-7 minutes. After this, the desired humidity indicators will appear on the display.
If you still had to open the incubator lid, then real readings will be ready only after 40-60 minutes.
How to properly use an electronic hygrometer?
In order for the device to work properly for many years, it is necessary to protect it from mechanical influences, in particular from impacts and tugging on the wire on which the sensor is attached.
Do not place the hatching apparatus, and therefore the moisture meter, under the sun or in a draft. This may have Negative influence for the future brood.
An important condition for the normal functioning of the device is temperature regime, which can vary from -40 to +70⁰С.
Avoid contact of the hygrometer with liquid, dust and dirt. Particular care should be taken when handling 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, you need to study specifications of all products on the market.
- Pay attention to the measured pressure parameter. It can be relative (RH) and absolute (g/m3).
- Think in advance about how many eggs will fit in the trays. Once you have decided on this indicator, tell your sales consultant 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 a residential area, pay attention to the degree of its protection. It is usually measured on the IP scale. The values of this scale indicate the degree of reliability and level of resistance of the device to water, dust and dirt.
As noted, the standard temperature range of a hygrometer is -40 to +70⁰С. However, if you are going to use 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 incubator humidity meter?
Despite the fact that a ready-made device for measuring humidity is not that expensive, some poultry farmers recommend making a device designed for the same purpose yourself. They explain this by the fact that the devices used for a homemade hygrometer give more accurate readings than their electronic counterparts.
How to make a homemade device:
- To do this you will need two regular mercury thermometer, which measure air temperature, board and water.
- The 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 in cotton cloth and tie it not very tightly with thread.
- 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, which 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 chick hatcher is 38%. Thus, the air humidity in the incubator is calculated.
Thus, the success of the chick hatching process is influenced 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 you can buy at any pet store or make yourself. However, the second option is quite labor-intensive.
Special moisture meters are used. Today there are needle, contact and chip modifications. In terms of parameters, they are quite different. However, there are not many manufacturers of moisture meters on the market. The main companies include, first of all, EMCO and Valcom. On average, a good moisture meter on the market costs around 1,500 rubles.
How to do it yourself?
If necessary, you can make a moisture meter for wood with your own hands. Its circuit includes a dielectric-type sensor. The device will also require a compact generator. Its maximum frequency parameter must be no more than 30 MHz. Contacts for homemade model It is more advisable to select needle-shaped ones. Also, to make a moisture meter for wood with your own hands, you will need a three-channel type microcircuit.
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 of the tubular type. It is more advisable to select a lowercase display. Compared to text counterparts, it is simpler. The electrodes used in moisture meters are capacitive ones. In turn, the catcher will need to be installed resistive. Lastly, batteries are selected for the model. In this case, you can use regular AA batteries.
Contact models
Contact wood moisture meters are well suited for working with plywood and parquet. Additionally, in the construction industry, devices are used to determine the humidity of panels. If we talk about contractual features, then low-frequency generators are used in the devices. The probes themselves are installed in a tubular type.
The dielectric constant of most moisture meters does not exceed 3 F/m. Maximum temperature models of this type are capable of holding at 40 degrees. The display is used in both line and text types. Many modifications are equipped with temperature sensors. Many devices have a calibration function. On average, a high-quality moisture meter costs around 2 thousand rubles.
Needle moisture meters
Needle moisture meters for wood are usually used for pine or spruce. Sensors in all configurations are of the dielectric type. If we talk about parameters, then the measurement accuracy generally fluctuates around 0.2%. The maximum humidity threshold for devices does not exceed 35%. Minimum permissible temperature for models is 0 degrees. Microprocessors in many devices are used with amplifiers. The average price for a wood moisture meter (needle type) is around 1,200 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. The catchers themselves are installed of the resistive type. The minimum humidity threshold for models does not exceed 5%. In turn, the devices are located at level 1 RN. Displays of moisture meters are often used in 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 AR
In the construction industry, the presented moisture meter is in great demand. It is ideal for working with parquet and panels. This moisture meter is also 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 wood moisture is measured quickly. The electrodes are of the capacitive type.
The maximum humidity threshold does not exceed 40%. In terms of size, this moisture meter is very compact and belongs to the class of portable devices. According to the documentation, its weight without batteries is 80 g. The resolution of the model is at the level of 1.3 pH. The maximum permissible temperature of the model is exactly 35 degrees. The presented device must not be used in cold weather. 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. If you believe customer reviews, the resolution of the device is quite high. The generator itself is used at 22 MHz. According to the documentation, the maximum permissible temperature is 40 degrees. The display in the device is of text type.
The batteries are 1 mAh, so they last a long time. In this case, the catcher is provided by the manufacturer as a resistive type. If you believe the reviews of experts, then problems with determining the importance of wood chips do not arise. The maximum measuring depth is 10 mm. The user can purchase the presented moisture meter for 1,400 rubles.
Model "Valkom EM4806"
This 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 0.2%. The maximum permissible humidity threshold is 30%.
The catcher in the device is of a resistive type. The microcircuit is a three-channel one, and the generator is installed as a low-frequency one. According to the documentation for the device, the case is equipped with an IP 62 protection system. The presented model weighs exactly 80 g. The moisture meter’s memory is enough for 30 thousand measurements. The user can buy it for 1,500 rubles.
Lyudmila Dudoladova
For our weather site, we decided to make a Christmas tree with pine cones. After all, an ordinary cone can turn into a unique weather forecasting device.
The fact is that cones tend to close or open depending on air humidity. When it's dry outside, bump "reveals" so that the wind can carry its seeds and scatter them 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 preserve the seeds until a more convenient time, since it is easier for the wind to transport them dry.
So we decided to make a Christmas tree with pine cones to monitor the weather at our weather site.
They cut out a Christmas tree from plywood, sanded it, painted it green color (the Dokuchaev family, Alina and Arseny, helped us with this)
Using decorative buttons and strong threads, we attached the cones to the Christmas tree.
Now we are looking forward to the rain, when the scales close, showing that air humidity has increased.
A pine cone is a unique phenomenon in nature; you just need to learn how to use it. I hope that by observing the cones, children will understand why they open and close.
Children should come to the conclusion that the pine cone is a natural weather predictor.
Publications on the topic:
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 and broaden our horizons.
How many have become Lately include foreign words in our everyday speech! It doesn't matter what field of activity it is. The fact remains.
Do-it-yourself busy board! Dear colleagues, thank you for paying attention to the manual I made - a busy board. What is a busy board?Buy board.
Dear colleagues! I present to your attention a handmade board. Meet this girl Kleopina.
Photo props are made from thick paper or cardboard analogue of any object. It could be glasses, mustaches, lips, hats, funny ones.
Play is one of the most important activities of a preschooler, during which the appropriation of experience and adaptation to the environment occurs.
Do-it-yourself carpet. Carpet "Larchik" is a unique manual by Vyacheslav Voskobovich, a famous manufacturer of educational toys. Carpet.
Today, much attention is paid to the level of air humidity in residential premises. Many people mistakenly believe that this indicator is actually not as important as air humidifier manufacturers say.
But if you take a closer look, the level of environmental humidity 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 out, 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 due to lack of moisture and decreased immunity, causing rapid fatigue and drowsiness.
And in general, people’s well-being with reduced humidity is far from ideal. However, this is not even the worst thing! Excessively dry air can cause the development of chronic rhinitis, allergies and even asthma.
Children and people suffering from various chronic diseases are especially sensitive to changes in air humidity.
It’s not even worth mentioning that the premises themselves suffer from an excess or lack of moisture in the air. For example, if there is excessive moisture content, mold fungi settle on the walls of the house and problems arise. bad smell dampness.
If the air is excessively dry, they quickly lose their appearance all furniture made of wood and parquet. Cracks may appear on them, indicating that they are drying out.
Device for measuring air humidity levels
And therefore, every home should have a device that measures this important indicator. One of the simplest and available types A hair hygrometer is rightfully considered a device that allows you to control the level of humidity. It is easy to use, but at the same time allows you to obtain the most accurate data.
Design features of the device
It has a fairly simple design. It consists of a metal frame with fat-free synthetic or natural hair stretched over it.
A small weight 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 air humidity is indicated as a percentage.
When air humidity changes, the needle moves along the scale and shows us its current level.
Operating principle
The operating principle of the device is based on the ability of hair to change its length in a humid environment. When this parameter decreases, the hair becomes shorter, and when it increases, on the contrary, it becomes longer.
When the length of the hair changes, the pulley rotates and moves an arrow along the scale, indicating the level relative humidity environment. Each hygroscopic scale division corresponds to 1% relative humidity.
Features of use
The 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 in the installation location of the device, that is, you should not install the device on top of any operating 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 move it from place to place or subject it to sharp blows and shocks, as this may cause the device to fail.
However, in order to have a hygrometer at home, you don’t have to buy one at all, since you can simply make this device yourself.
DIY hygrometer
In fact, making this device is much simpler than it might seem at first glance.
It is necessary to take human or fat-free horse hair at least 40 cm in length. A small weight needs to be placed on one end of the hair.
A washed rod from ballpoint pen or the sharp end of a nail. It is very important that the weight of the load is sufficient to completely straighten the hair. It is recommended to use nitro glue to attach the weight to the end of the hair.
After this you need to take small sizes nail and place any plastic tube no longer than 5 mm on it. It is necessary that the tube rotates as freely as possible on the rod and does not slip off it.
The hygrometer must be mounted on a vertical base or a piece of plywood with a horizontal stand that serves as the base of the structure.
Now you need to drive a nail with a plastic tube 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 secured with its free end to the 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 must be 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 this, all that remains is to make a scale out of paper, which is then glued to the back of the plumb line.
As you can see, making a hygrometer with your own hands is not a difficult task. The main thing is to choose the right source materials for its implementation.
Craft and mount 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 out a flag from thick cardboard and laminate it so that it does not get wet when it rains.
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 attach them to a stick. The weather vane is ready. Install it on your weather site, orienting the arrows to the cardinal points.
With older children (6–9 years old), making weathervanes fits perfectly into geography lessons, when you talk about how winds are formed, how the first navigators used knowledge about them, what the winds at “horse latitudes” mean, what trade winds are.
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 southern and northern latitudes were so light that sailing ships became calm. We had to wait for months for the right wind. Often the wait lasted 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 quantities from Europe. Therefore, these latitudes were nicknamed “horse latitudes”.
Using a weather vane, children mark the direction, strength and change of wind in their weather observation calendars. In this way, we not only introduce them to the basic meteorological instruments, but also to the methods and techniques of observation and processing of results.
DIY thermometer
Install a large one at the weather site thermometer and teach children to read air temperatures. This work is also preparation for understanding the concept of negative numbers in mathematics, which is offered to children aged 9-12 in a Montessori school.
Children aged 3–6 years will enjoy making their own thermometers from cardboard and colored thread. 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 red and blue (white) threads together.
- 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.
Checking with a real thermometer, the guys move the thread on their homemade thermometers, setting and recording temperature values 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 push pins;
- scotch;
- human hair about 10 cm long;
- a piece of thin wire.
Attach two buttons to the board at a distance of approximately 8–10 cm. Attach a wire to the bottom one so that it can move, that is, not tightly. Attach the end of the hair to the top button, then pull it around the wire and secure it to the top button. The device is ready.
Teach children how human hair reacts to air humidity by becoming shorter or longer. At high humidity it will lengthen, thus moving the arrow down; at low humidity, on the contrary, the hair will become shorter and raise the wire arrow upward. This property of hair is used to make a hygrometer.
DIY precipitation gauge
Will complement your weather site precipitation gauge- a device for measuring liquid and solid precipitation (hail). Take an ordinary bucket and place it on a small hill (pedestal, stool). The accumulated sediment is poured into a measuring cup with a scale. Children record the results in their calendars.
A weather station built with your own hands is not only part of a Montessori educational environment, but also a fun and educational opportunity to observe the weather and keep a journal of observations.
When 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 the Montessori program in economic geography, we talk about how climatic conditions in general affect the economies of different countries.
