DIY liquid barometer. Making a barometer yourself

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In today's experiment we will try to make a barometer from an ordinary glass bottle. Instructions for making it in large quantities are present on various sites (and of the same type, that is, most likely, thoughtlessly copied from each other). For example:

The principle of operation of such a barometer quite simple: a volume of air is maintained inside the bottle at a fixed pressure. The poured liquid acts as a moving piston between this volume of air and the external atmosphere. If the external (atmospheric) pressure changes, then the liquid level in the tube will also move. So, when the pressure increases, the level of the column will fall, and when the pressure decreases, it will rise.

Let's try to make a barometer. For this we will need: a glass bottle (0.5 liter), a drinking straw, electrical tape. Using electrical tape, we make a cork on the straw that will fit tightly into the neck of the bottle (you can also take a regular cork, I didn’t have one on hand). After the liquid is poured into the bottle and the straw is inserted, the internal air volume must be sealed. You can do this, for example, by filling the neck with “Moment” glue (during its drying, do not allow temperature changes, otherwise the glue will swell with bubbles due to escaping air).

Once everything is dry, the barometer is ready for use. Here we discover an unpleasant feature: it is highly sensitive, not only to pressure, but also to temperature. As a result, air either enters inside the bottle, or, conversely, water pours out. Thus, it is extremely difficult to use such a barometer for its intended purpose.

To prove it, let’s do some calculations “on our fingers”:

Atmospheric pressure changes by about 20 mm. Hg column from normal. Thus, the relative change in pressure is:

delta_P / P = 20 / 760 = 0.0263

This change results in the same relative change in the volume of air contained in the bottle. We will assume that the bottle is half filled, i.e. V = 250 ml. Then

delta_V = V * 0.0263 = 6.58 ml = 6580 mm 3

At the same time, the volume of the straw (diameter 2 mm, length 20 cm = 200 mm):

V sol = 3.14*1*200 = 630 mm 3

It can be seen that the volume of the straw is certainly not enough to contain all the liquid that will rise or fall. The same problem occurs with temperature changes. Even if the temperature changes by only 5 degrees, the relative change will be:

delta_T / T = 5 / 270 = 0.019

which is comparable in effect to a change in pressure.

Conclusions:

It is necessary to keep such a barometer in a room with a constant temperature (you can in the refrigerator, but the glass fogs up and it is difficult to check the liquid level).

It is necessary to use a larger diameter tube.

If these conditions are met, you can count on the functionality of this device.

If you want to know in advance about weather changes, you can make a barometer with your own hands. This device shows changes atmospheric pressure, by whose fluctuations the weather can be predicted.

So, if the atmospheric pressure drops, then precipitation is possible and the weather will worsen, and vice versa, if the atmospheric pressure rises, then we can talk about the weather improving. Of course, you can trust reports from hydrometeorological centers or look at the weather on weather websites, but it is better to have a similar device in your home and rely on its readings.

Barometers are produced and sold different types, but you can make a device that responds to fluctuations in atmospheric pressure at home.

These interesting “things” will help you navigate the weather, and their manufacture does not require complex technologies or materials. It turns out that some kind of barometer can even be made from spruce branches.

Spruce barometer

Siberian hunters have long known that branches coniferous trees tend to fall before precipitation and are understood on the eve of sunny, clear weather. Even dry spruce branches retain this feature, so they can be used to make natural barometers that will show weather changes 8-12 hours before changes.

To make such a barometer, you need a piece of the trunk of a dry small tree (25-30 cm long) along with a branch 30-35 cm long. The trunk and branch are cleared of bark and attached to a board that is hung on the wall. In this case, the branch should be positioned so that when lowering or raising the free end of the branch, it moves parallel to the wall and does not touch it. Raising a branch signals clear weather, while lowering a branch indicates bad weather.

You can even attach a metal or plywood scale to the board with marks every 1 centimeter. After some time of use, it will be possible to determine the capabilities of the branch and sign the indicators “precipitation”, “variable”, “sunny”

Light bulb barometer

This barometer will require a burnt out incandescent light bulb. At the beginning of the threaded base, a hole with a diameter of 2-3 mm is drilled. You need to drill carefully and with minimal effort to avoid cracking the glass. Fill through the resulting hole clean water up to half the flask. You need to add 2-3 drops of ink to it.

Next, wait until the inner walls of the flask dry out and hang the barometer light between the window frames, preferably on the north side. If the windows are located on the south side, then the light bulb should be hung at the top of the window. Within a few hours you can take readings.

If the inner walls are covered with small droplets of condensation, then the weather will be cloudy without precipitation.
With droplets of medium size, between which dry vertical stripes have formed, partly cloudy weather is expected.
Large drops near the surface of the water in the light bulb and a dry neck indicate that precipitation will pass by.
Drops of water on the north side of the bulb indicate rain the next day in the second half.
If the inside of the light bulb is covered with large drops of condensation, there will be short-term rains. And if the drops become larger and flow down, then most likely there will be a thunderstorm.
If the walls of the light bulb are completely dry, then the weather will be good

This barometer can be used in spring, summer and autumn at temperatures above zero.

Fir barometer

A fir branch 10-12 cm long is cut. The needles are removed from it, except for one. The branch is attached to the board so that the fir needle can freely fall and rise.

The board with a twig and a needle must be brought to the oven so that the moisture evaporates from it. In this case, the needle rises up and you will need to make a mark “sunny” with the number 1. Then you need to bring the device to the steam, and when the needle goes down, mark the number 10 and write “Rain”. Between these marks marks are marked in ten divisions.

A homemade barometer should be placed in a shaded place, away from direct sunlight. Such a device can be built during a hike and learn in advance about weather changes, focusing on the position of a small fir needle.

Fir cone barometer

You can even make a barometer from a fir cone. This device can predict weather changes several hours in advance. To make such a homemade barometer, you need two smooth wooden planks and a dry pine cone.

Two elements are cut out of the boards: a base square with a side of 70 mm and a side with dimensions of 70x150 mm. The ends of the workpieces are processed with a large file and the surfaces of the boards are cleaned with sanding paper. The elements are connected with glue and secured with small nails as shown in the figure. A scale is cut out of cardboard or thick paper with divisions and symbols for sunny and rainy weather. At the side, a large dry fir cone is attached to the base. A dry straw with a paper arrow at the end is glued to one of its scales from below.

The device will work based on the fact that the scales of fir cones are pressed tightly against each other when humid air and vice versa, they open in dry weather. A homemade barometer should be placed on the balcony or outside the window, and with its help you can easily determine whether there will be precipitation or sunny clear weather today.

Barometer from a bottle

For such homemade device You will need a clear bottle, a glass tube and a stopper. The bottle is filled one third with distilled water. For better visibility, the water can be tinted, but distilled water is used due to the fact that regular water can deteriorate after a while. A hole is cut in the cork into which a glass tube is inserted. The hole around the tube is covered with plasticine or sealant. The bottle is plugged with a cork and a tube, and the homemade barometer is ready. When atmospheric pressure changes, the water level in the tube will change. When air bubbles begin to emerge from the tube, this will indicate that the atmospheric pressure is high and the weather will be clear. If water pours out of the upper end of the tube, then the pressure is low and the weather will be rainy.

Home hydrometeorological center

A homemade hydrometeorological center can be made using two thermometers. One of them is wrapped with damp cotton wool or cloth and placed in a jar of water. It is necessary to ensure that it is constantly wet. Using the table below, the readings of both thermometers are compared and the weather is determined.

Razinkin Vladimir, Losev Nikita, Bondar Daria

BAROMETER WITH YOUR HANDS

With. Yagunovo

Content

Introduction………………………………………………………………………………3

1 Theoretical part……………………………………………………………5

Practical part………………………………………………………9

DIY barometer……………………………………………………9
Carrying out the experiment……………………………………………………………10
Conclusion………………………………………………………………………………10

Conclusion…………………………………………………………………………………11

References……………………………………………………………12

Applications………………………………………………………………………………13

Introduction

Often, in order to find out the weather for the next day, we listen to the weather forecast. From it we learn about the expected temperature, presence of precipitation, wind speed and atmospheric pressure.

The topic of our work is relevant, because each of us, before going outside, wants to know what is there outside the window? Proof of the relevance of our topic is the survey we conducted among students at the Yagunov School. Each of those surveyed wants to know what the weather is like before going outside. 25 people out of 35 survey participants do not know how to make a barometer with their own hands, but would like to learn.

Every day we encounter amazing phenomena: for example, the force that operates thanks to air.

We were interested in: “What does atmospheric pressure affect? Why is it reported in the weather forecast?” It turned out that changes in atmospheric pressure are associated with changes in weather. If the pressure rises, then you can expect clear weather, and if it drops, then cloudy. Changes in atmospheric pressure also affect the well-being of people suffering from hypertension.

Is it possible to create a device for observing changes in atmospheric pressure with your own hands?

We decided to play meteorologists! They measure atmospheric pressure because it shows the movement of air masses that affect the weather.

Object of study: atmospheric pressure and methods for measuring it.

Subject of study: atmospheric pressure measuring device

Hypothesis: You can create a device to monitor changes in atmospheric pressure at home.

Target: making a device for observing changes in atmospheric pressure with your own hands.

Research objectives:

Analyze the literature on this topic;

Explore who first developed the barometer;

Get acquainted with the options for manufacturing barometers;

Analyze the operation of the barometer at home.

Planned result: Determining atmospheric pressure using a homemade barometer.

Theoretical part

To measure atmospheric pressure, instruments calledbarometers . ( The word barometer comes from two Greek words: baros - heaviness, metreo - measure)

The first barometer was invented by a scientistVXVIIcentury. The mercury barometer, invented by Torricelli, is very inconvenient to use and dangerous.In liquid barometers, pressure is measured by the height of the liquid column () in a tube sealed at the top and with the lower end lowered into a vessel with liquid (atmospheric pressure is balanced by the weight of the liquid column). Mercury barometers are the most accurate; they are used on.

B. Pascal created a water barometer in 1646, but its dimensions turned out to be very large. The height of such a barometer is more than 13 m.

In practice, a metal barometer called a metal barometer is used to measure atmospheric pressure.ohm. ( Aneroid translated from Greek means liquid-free. This is what a barometer is called because it does not contain mercury). It shows the atmospheric pressure acting on the corrugated thin-walled metal box, in which a vacuum is created. When atmospheric pressure decreases, the box expands slightly, and when it increases, it contracts and acts on the spring with an arrow attached to it.

We looked at various sources that described creating a device with our own hands. The easiest barometers to make are the following:

Fir cone barometer

To make a simple device that predicts the weather several hours in advance, you will need two smooth wooden planks. For the base you need to cut a square with a side of 70 mm, and for the side a rectangle of 70x150 mm.

File the ends with a large file, and then clean the entire surface with emery cloth. Connect them with glue, strengthening them with small nails, as shown in the figure. You need to cut out a scale from thick paper, draw divisions and two signs on it: the sun and an umbrella. At the very sidewall, attach a large dry piece of paper to the base. pine cone. To one of its lower scales you need to glue a dry straw with a paper arrow at the end. (Appendix 1. Fig. 1)

It is necessary to cut a 10-12 cm long branch of young fir with needles. Remove all needles from it except one. And it will become a barometer.

To do this, you need to attach the branch with two small nails to a board made of plywood, wood or plexiglass. The only requirement is that the fir needle can move freely up and down.

Then you need to bring the needle to a hot stove, oven, or place it close to gas burner... The moisture from the surface of the branch will very soon evaporate, and the needle will rise up. Make a mark on the board - 1, and then write “Sunny”.

Next, bring the board to the steam from the boiling kettle - the needle, on the contrary, will go down. Make a mark - 10, and then write "Rain". All that remains is to calibrate our barometer into 10 parts.

The barometer should be hung in the shade so that direct rays do not fall on it. All is ready. Now, when leaving the house, we can predict both a sunny day and rain, depending on the position of the single needle of a young fir. (Appendix 1, Fig.2)

Barometer made from a tin oil can

Such a barometer can be made from a small tin oil can with parallel sides.

It is necessary to select a plug that would tightly cover the only hole of the future barometer. Before you put the cork in place, you need to make a hole in it of such a diameter that you can pass a transparent tube-straw for cocktails through it. However, it is better to use a glass tube with internal diameter holes 1.5 - 2.0 mm. The container is filled 2/3 with colored water, a tube with a stopper is inserted into the hole, and the tube should contain a little of the same colored water. As atmospheric pressure increases, the liquid level in the tube will rise, and vice versa. Such a barometer must be mounted on a stand with a vertical ruler. You can calibrate it by taking readings from a real barometer. Instead of metal container You can use any small glass bottle. After filling with colored water and installing the stopper with the tube, add some water into the tube. Since the barometer body is rigid, when pressure increases, the water level will decrease, and when pressure decreases, it will increase. (Appendix 2. Fig. 3)

Glass bottle barometer

In order to make a barometer, we need to have3 simple things :

Glass bottle, 0.5 liter volume

Glass tube

Rubber plug with hole for tube

At the bottom, the tube should not touch the bottom of the bottle by 15-20 mm.

At the top it should stick out from the cork by 35-45 mm.

The bottle should be filled halfway with water, preferably rainwater.

If the water column in the tube is at the bottom, the atmospheric pressure is high; at the top, it is low. It happens that it overflows from the top - very low atmospheric pressure. (Appendix 2. Fig. 4)

Light bulb barometer

You need to take a burnt out light bulb, and where the base with the threaded part begins, carefully drill a small hole with a diameter of 2-3 mm. You need to drill very carefully, applying minimal force, otherwise the cylinder may crack or break. Once the hole is drilled, pour into it tap water, filling the glass flask halfway. Then add two or three drops of ink or ink to it and mix. The barometer is ready. All that remains is to wait until the inner wall of the flask dries out and hang the barometer between the window frames. It is best from the north side, where it will not receive direct sunlight. If the windows face south, install at the top of the window. After a few hours, you can take readings. Our barometer can predict the weather 24 hours in advance quite completely.

Practical part

2 .1 DIY barometer

At home we do not have a device for monitoring atmospheric pressure, and therefore we decided to make a device with our own hands from improvised materials.

Equipment

In order to make a barometer, you must have:

glass jar with wide neck,

balloon,

rubber,

straw,

sheet A4,

scotch,

scissors,

paints.(Appendix 4. Fig. 6)

Creation plan

Cut from balloon the circle is slightly larger than the diameter of the jar.

Pull the cut circle over the neck and secure it with an elastic band.

Cut the tip of the straw diagonally and sharpen one of its ends.

Using adhesive tape, secure the other end of the straw with tape in the middle of the stretched rubber film.

Secure a sheet of paper near the jar so that the tip of the straw lightly touches it. After this, mark “zero” where the straw touches the sheet. Below and above this value, with an interval of 1 mm, mark the numbers 1, 2 and 3.

Principle of operation

1) As atmospheric pressure increases, the film bends down, the straw rises up and indicates “Clear”.

2) When the atmospheric pressure decreases, the film rises up, the straw goes down and shows “Cloudy”. (Appendix 5. Fig. 7)

2.2 Conducting the experiment

We decided to conduct an experiment to make sure whether the device works correctly. Every day at 8 30 hours, we recorded the READINGS of our device and entered the result into a table, then observed the weather during the day, recording the result in the “WEATHER” column. (Appendix 5. Table 1)

After a two-week experiment, the values of the instrument and weather indicators coincided, which confirms correct work created device.

The barometer we have created shows the change in pressure outside the jar. If the pressure increases, the air begins to press on top of the rubber lid of the jar and the straw rises. And vice versa, if the pressure decreases, then the air presses on the sensitive membrane from inside the jar and the straw drops.

You cannot see accurate indicators of atmospheric pressure on such a barometer, since the membrane of the tensioned ball is not thin and sensitive enough. The tube goes down and up by only one division, but the increase and decrease in atmospheric pressure can be seen very clearly. These results were consistent with weather announcements.

Observations have shown : With the increase in atmospheric pressure, the weather was clear and sunny. When the pressure drops, it becomes cloudy and stormy.

Using the device we built, we can predict the weather.

Conducting these experiments is not difficult, but interesting. They are safe, simple and useful. Our barometer warns loved ones about changes in atmospheric pressure, and they take action in time. We will not be caught by surprise by bad weather.

Conclusion

During the period of work on the project, we studied various literature, which helped us make our own device for determining atmospheric pressure. During the experiment, we observed the operation of our barometer and, based on its readings, learned to predict the weather for the next day. Now we know that this expensive device can be made with your own hands at home. This is not the end of our research, and in the future we plan to make other versions of barometers from scrap materials and test them in operation.New research is ahead!

Bibliography

Book of experiments. Just about the complex / Transl. from Italian I. Guryanova. – [Text] M.: Eksmo, 2013. – 128 p.

Children's encyclopedia “I want to know everything” // [Text] M. “Planet of Childhood” – 2003. – P. 260–261.

New schoolchild encyclopedia //– [Text] M. “Swallowtail.”– 2009.– P. 128 – 129.

Annex 1

Rice. 1 Fir cone barometer

Fig.2 Fir barometer

Appendix 2

Fig.3 Barometer made from a tin oil can

Fig.4 Barometer from a glass bottle

Appendix 3

Fig.5 Barometer made from a light bulb

Appendix 4

Rice. 6 Equipment for making a barometer

Appendix 5

Mainly cloudy

Fig.7 Operating principle of the barometer

DAY

INDICATIONS

WEATHER

Monday(24.02)

Clear

Sunny

Tuesday(25.02)

Clear

Sunny

Wednesday(26.02)

Mainly cloudy

Cloudy, snow

Thursday(27.02)

Clear

Sunny

Friday(28.02)

Mainly cloudy

Cloudy

Saturday(01.03)

Mainly cloudy

Cloudy

Tuesday(04.03)

Mainly cloudy

Cloudy

Wednesday(05.03)

Clear

Sunny

Thursday(06.03)

Clear

Sunny

Friday(07.03)

Mainly cloudy

Cloudy

How to make a barometer from a light bulb

To make a barometer you will need a burnt out glass light bulb with a large glass bulb, sandpaper, glue, a drill or screwdriver, machine oil, copper wire with a diameter of 2-3 mm, ink from ballpoint pen.

It is necessary to make a hole at the junction of the base and the glass bulb. To do this, place a drop of machine oil on the place where you will drill the hole. Rub two sheets sandpaper between themselves. Apply the crumbled abrasive to machine oil and rub until a thick mass is formed. Take a piece of copper wire with a diameter of 2-3 mm and clamp it into the drill chuck. It will serve as a drill for us. Wrap the glass bulb in a towel and clamp the light bulb base between two wooden planks. Carefully drill a hole in the light bulb. When drilling, it is necessary to apply minimal force so that the glass bulb does not crack.

Through drilled hole Squeeze some ink from a ballpoint pen into the flask. If you don’t have ink, you can use a piece of crayon lead, first grinding it to a powdery mass. Fill the glass flask halfway with tap water. Stir until the ink or lead if you used a chemical pencil are completely dissolved.

Take the rope and wind it around the base in a spiral, leaving a free end about 30 centimeters long. Apply glue to the base and leave the workpiece to dry for a couple of hours.

After the glue has dried, you need to hang the barometer between the window frames. It is advisable to hang the barometer on the north side so that it is not exposed to direct sunlight. If the windows face south, then the barometer must be hung at the very top window frame.

How to decipher barometer readings

If the inner walls of the glass bulb are covered with small drops, then tomorrow is expected to be completely cloudy, but without precipitation.

If the walls are covered with medium-sized drops and dry stripes are visible between them, then partly cloudy weather is expected.

If the walls of the flask are partially covered with large drops, there will be short-term precipitation.

If drops fill the light bulb from the base to the border with water, then there will be thunderstorm precipitation.

If sufficiently large drops are located only at the border with water, and the rest of the flask remains dry, then the thunderstorm front will pass by, 40-60 km from you.

If during rainy weather the walls of the flask become dry, then tomorrow there will be good weather without precipitation.

This barometer can only be used when the air temperature is positive. In winter, the barometer must be removed from the window frame, as the water may freeze and the glass bulb will crack.

U healthy people a change in weather does not have much impact on their well-being, but weather-dependent people react to such changes very painfully. The barometer-alarm proposed in the article is intended to inform weather-dependent users in real time about the current value of atmospheric pressure, when the atmospheric pressure value goes beyond the established limits and about its sharp jumps.

Let’s say right away that the device presented in this review has a number of attractive features:

The user independently sets the boundary values - minimum and maximum thresholds.
If the atmospheric pressure exceeds the maximum threshold or falls below the minimum level, the device will produce intermittent sound signals and “Threshold” light signals.
After the sound signals are repeated five times, the sound turns off, and the light signal will be given until the atmospheric pressure returns to the specified limits.
The user sets the magnitude of the controlled jump in atmospheric pressure for a set time interval.
In cases where the atmospheric pressure in a given time interval deviates by an amount exceeding the controlled jump, the device will give intermittent sound signals and light signals “Jump”.
After the beeps are repeated five times, the sound will turn off and the light will continue until the barometric pressure returns to a level where the surge is considered uncontrollable.
Atmospheric pressure values are presented in the device in “mmHg”. Art." - millimeters of mercury.

Do-it-yourself home barometer: circuit diagram and list of elements

The barometer, assembled according to the above diagram, has the following design features:

The device is based on the ATmega8 microcontroller.
Resistor R1 and capacitor C3 provide a hardware reset of the MK when power is applied.
Capacitors C2 and C1 protect the power circuits from high-frequency interference and power surges.
The atmospheric pressure value comes from the BMP1 sensor (GY68 BMP180).
The pressure sensor is controlled via the TWI (I2C) interface.
The sensor inputs are connected to the supply voltage by resistors R8 and R10.
The Nokia 5110's LCD screen is used to display information. The display shows information about the current atmospheric pressure, as well as device settings.
Operational indication of the atmospheric pressure status is carried out using LEDs VD1–3 (“Normal”, “Threshold”, “Jump”).
Sound signaling is carried out using a low-frequency amplifier using transistors VT1–2 and loudspeaker SP1. The sound volume can be adjusted using variable resistor R5.
The device is configured using the buttons SA2 (“Installation”), SA3 (“+”), SA4 (“-”).
Pressing the SA5 (“Screen”) button displays the main screen with the current barometric pressure value.

Attention! When setting up the MK, the following fuses are used: HIGH=0xD9, LOW=0xE1.

Do-it-yourself barometer: features of software and device operation

The program for MK is written in C language in the AtmelStudio environment (Version 7.0.1006). The program code is given in the Appendix in the file attached at the end of the review (SignalBarometer.rar Archive of the Atmel Studio 7 project in C).

In order to reduce the power consumption of the device, the method of “falling asleep” of the MK in the “power-save” mode was used. In this case, the current consumption in sleep mode is reduced to 20 μA. According to calculations, this allows you to use two 1.5 Volt AA batteries for 4 months.

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To wake up the MK from the “power-save” mode, an internal asynchronous timer-counter No. 2 is used, which runs constantly. The counter timer master oscillator uses a quartz resonator Y1 with a resonance frequency of 32768 Hz.

Timer-counter No. 2 is configured so that every 8 seconds it overflows and calls an interrupt, which “wakes up” the MK. After waking up from timer-counter No. 2, the MK finds out whether 10 minutes have passed since the previous awakening. If not, then the MK gives a light signal “Normal”, “Threshold” or “Jump” depending on the condition that developed after the previous measurement, and then falls asleep again for 8 seconds.

If 10 minutes have passed since the previous measurement, the device performs the following sequence of operations:

The MK sends a command to the pressure sensor to take measurements.
Receives a response from the sensor.
Processes data by comparing the resulting value with threshold values or conditions for recording a jump.
Gives a light signal “Normal”, “Threshold” or “Jump”, and then a sound signal, if necessary.
After this, the device “falls asleep” again for 8 seconds.

The second source of awakening the MK is an external interrupt at the INT1 input, which occurs when the “Screen” button is pressed. MK, having awakened and found out that it was “awakened” by the “Screen” button, turns on the liquid crystal display of the Nokia 5110 and displays the current value of atmospheric pressure and other information on it. The display will display information until the “Screen” button is released. After releasing the “Screen” button, the MK turns off the display by issuing the “power-down” command to it, then the device “falls asleep” itself.

The third and final source of device wake-up is an external interrupt at the INT0 input, which occurs when the “Set” button is pressed. MK, having awakened and found out that he was “awakened” by the “Install” button, turns on the liquid crystal display of the Nokia 5110 and displays the device’s settings on it. Clicking the “Set” button again moves the cursor to the next parameter. Pressing the “+” and “-” buttons changes the value of the parameter on which the cursor is positioned. After pressing the “Install” button on the last parameter, the MK turns off the display and “falls asleep” until the next awakening.

How to make a barometer with your own hands: housing, printing chamber, batteries

The device is made in a housing distribution box"Tuco 79x79x32, for open wiring, color white (65004)". The external design of the case is presented below:

The board is made on one-sided foil fiberglass. Its dimensions are 72x72 mm. There are 9 jumpers on the top of the board. They are highlighted different colors. If you use double-sided printed circuit board, then the jumpers can be converted into tracks. The location of the parts on the board is shown in the photo below:

The board layout is shown in next photo(note that the image is mirrored):

The speaker is attached to back wall device body. The assembly components are shown in the picture:

Batteries (2 AA cells) are placed in battery compartment in specialized crib holders:

Setting up a home barometer

The photo above shows the controls used when setting up the device. Each of the regulators has its own purpose:

The “Setup” button is pressed to enter the corresponding mode. The display will show the adjustable parameters.
Use the “+” and “-” keys to set the required parameter value.
To move on to setting the next parameter, press the “Set” button again.
To exit the setup mode, press the “Setup” button several times.
Volume adjustment sound signal carried out by the “Volume” potentiometer. To make adjustments, you must use a miniature Phillips screwdriver. If necessary, a potentiometer with an external handle can be installed for ease of adjustment.

Regarding parameters such as “Upper threshold”, “ Lower threshold" and "Jump", then they are specified in mmHg. Art., and the “Interval” of jump measurement is set in hours.

Below is a demo video of a home barometer for weather-sensitive people:

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