How does a mercury barometer work? Barometer - a useful and beautiful gift

The barometer is key instrument in the practice of weather forecasting. A barometer measures atmospheric pressure, which is determined by the weight of the air above us (from the top of the atmosphere to the sea surface). If the pressure is high, then this means that there is a large number of air above us, if low, then there is less air than anywhere around, farther from us. This is impossible to see by eye, since the air is invisible.

We are interested in atmospheric pressure because it informs us about the distribution of air masses around us and the expected winds that occur when air flows from areas of high pressure to areas of low pressure. The greater the pressure difference over neighboring territories, the stronger the wind will be.

In weather forecasts and on meteorological maps, it is customary to reflect atmospheric pressure in millibars (mb). We need to know whether the pressure transmitted by the official forecast or taken from the barometer is high or low, and whether its change is large or small. To do this, it must be remembered that the "standard" atmospheric pressure is 1013 mb, but for each locality and season it may differ slightly from this figure.
On weather maps, pressure is indicated only by the last two digits (the previous ones are omitted). 1024 will be shown as "24", or 996 as "96". In most cases, the actual pressure at the centers of cyclones and anticyclones is written in full and underlined, but individual isobars (lines of equal pressure) have only two digits. Typically the isobars are drawn at 4 mb intervals on USA charts, although maps from other countries may have intervals from 2 mb (Australia) to 5 mb on European maps.

Types of barometers
The first barometer was invented by Evangelista Torricelli in 1643. Torricelli was often spoken of as a student of Galileo, but he only worked with him for 3 months before the latter's death and invented his first mercury barometer a few years later.

Torricelli mercury barometer

The device was a hollow glass tube, closed at one end and filled with mercury, which was lowered with the open end into a vessel with mercury. The air pressure on the open surface of the mercury balanced the pressure of the mercury column in the tube, and its level was at a certain height - about 760 mm. mercury column. Of course, such a device was bulky and fragile and could not have wide application in practice.
Further improvement of the barometer followed the path of abandoning mercury and using sealed containers with a vacuum inside, and in 1847 the first aneroid barometer was designed by another Italian, Lucien Vidi. "Aneroid" means without liquid. This type of barometer is still in use today.

Aneroid barometer

The "heart" of the tool is a sealed corrugated metal cylinder (bellows), from which the air is partially evacuated (1). When the external air pressure changes, this cylinder expands or contracts and this movement is transmitted through a system of levers (2) and a thread (3) to the axis of rotation of the arrow (4), which shows us the pressure on the value scale (5). The device is placed in a housing (6) with a glass over the scale (7).

Another useful instrument in meteorology is the barograph. This is the same aneroid barometer that can record pressure values ​​for a certain period (usually a week) with an ink line on a paper tape wrapped around a clockwork drum.

Barograph

The advantage of this device is that along this line we can directly observe the so-called barogram - the change in pressure over time, which in fact interests us the most.

Barogram - baric trend graph

This is very valuable information for weather forecasting. With a barograph, you will be relieved of the need to constantly record barometer readings, and then build baric trend curves from them.
Continuing the conversation about the barometer as an instrument, it should be noted that in the last decade, electronic barometers have appeared on the market. different sizes and accuracy. There are even barometers and barographs built into wristwatches. Some of them work on the principle of a conventional aneroid, but without mechanical system levers, but by measuring the change in the capacitance of an electric capacitor, the plates of which are located at the ends of the corrugated cylinder. Others use a different principle, measuring air pressure on a sensitive crystal.

Digital barometer

Digital barographs are also available for use, and here their advantages are obvious, since it is difficult to provide correct work traditional barograph in flight conditions on board an aircraft.

The value and price of a good barometer
In my opinion, a GOOD barometer is a great value. A traditional aneroid barometer would be an obvious choice. In most cases, knowing whether the pressure is falling or rising may be enough to judge whether bad weather is coming or vice versa. This judgment can be made with almost any working barometer if you periodically monitor its readings. But often we need to know the true, exact value of pressure. Moreover, if the pressure changes, we must be sure that it changes exactly as indicated by the instrument. I have seen barometers that beautifully show changes in pressure, but in a very narrow range, and absolutely do not react when the pressure is outside this range.
Knowledge exact value pressure is very important when you operate with a weather map. By measuring the wind speed and direction, you can calculate the corresponding pressure at your location, and by measuring the existing pressure with a well-calibrated barometer, you can judge how correct the information on the map you received is. key point here, most often, it is not so much the quality of the barometer as its calibration, clarification of the error and take it into account.
If you are paying $150 - $200 for a device, it should show the correct values. Unfortunately, not in all cases. Often you can pay big bucks for a barometer with an expensive bronze case and a beautiful dial and a totally unusable movement. Buy your barometer from trusted dealers and specialist shops.

Taking readings and caring for the barometer
Constantly check the accuracy of your barometer on the official radio. There are three factors that affect instrument readings during testing. The first is the height of the instrument above sea level - the higher, the lower the pressure value taken from the instrument. Second - there is a "zero" point of the device settings. It is adjusted by a screw, which, when turned, can move the arrow right and left, and every good barometer should have such an adjustment. For correct installation arrows the device must be located at sea level. Once you have received the pressure data, set the arrow to that value. And thirdly, the time of the radio message can and will differ from the time of pressure measurement at the weather station. Try to figure out this delay.
A barometer is a thin and precise instrument, and taking readings from it requires attention and accuracy. Small changes in values ​​can mean a lot in some cases. The barometer must be easily accessible so that the position of the thin needle in the fine divisions of the scale can be clearly seen, especially at night. You must look at the scale perpendicular to its surface, otherwise you will get an incorrect reading due to the parallax effect. Rice G110.

Speaking about caring for a barometer, it should be noted that it requires the same careful attitude as any precision measuring instrument. But there are several peculiarities arising from its nature. Avoid placing the instrument in an environment where atmospheric pressure is outside the barometer's measurement range. So, transporting it in an airplane can be fatal, since at an altitude of 10 km the atmospheric pressure is only 300 mb, and although the pressure in the cabin is compensated, it rarely exceeds 800 mb, which is outside the operating range of the device, and in the cargo compartment the pressure is generally equal to the outside . Be vigilant when transporting the barometer in a car. The windows should be open when you slam the door shut - this way you avoid a sudden pressure surge in the cabin when the doors are closed. I can't say how fast driving a car down a hill can damage the barometer, but if our ears feel it, then the change in pressure clearly lies outside the working area of ​​\u200b\u200bthe device.

Some tips for choosing a barometer
We can rarely find a combination of all the ideal properties of a device at an affordable price, so compromises are inevitable. But there are a few points that you need to pay attention to when buying a barometer.

1. Good stroke and bellows.
You can't judge this just by looking at the tool, but if you can look inside and you can see the bellows, it's good to know that the larger it is, the better the tool will run and work.

2. Dial size.
Larger size preferable because it is easier to take readings from it. The 10 cm diameter of the dial can be considered as the minimum. 12-15 cm are better, but they are more expensive.

3. Scale divisions
A scale with divisions of 1 mb is preferable.

4. Dial surface
A shiny or silver-plated surface can sometimes work as a mirror and help you see the reflection of the arrow, making it easier to take readings.

5. Temperature compensation
Ask the seller how good the temperature compensation of the barometer is. The temperature, for example, in a yacht below deck can reach 60 degrees, and in the tropics up to 100 degrees. Celsius

7. Housing
I prefer lightweight barometers. Any addition of bronze is for decoration and only adds weight and price without adding anything to the functionality of the instrument.

Pressure readings and baric tendency
Speaking about the pressure values ​​that the barometer shows us, it should be noted that the pressure above 1025 mb is considered as "high", and below 990 mb - as "low". But, of course, everything is relative - an atmospheric pressure of 1005 mb would be rather "high" if it is lower in the surrounding regions. It is always necessary to take into account the peculiarities of the region. Usually high pressure is accompanied by good weather with light winds, while at low pressure (below 1000 mb) bad weather with fresh and strong winds when the sky is completely covered with clouds and with rain. More information about using a barometer in a weather forecast will be described in the article "Weather Forecast" (forecast by barometer). Here we will focus on just a few important points.
Noting the importance of up-to-date barometer readings on this moment time, it must be said that the most useful use of a barometer is to determine the baric trend - changes in pressure over time.
It is generally accepted that a pressure drop of 1mb per hour deserves our attention. A drop of 2-3mb per hour could mean a storm is coming, although we still have calm weather in place. Examining many records of baric trends as storms approach, it is noted that they are usually accompanied by a slow, steady drop of 2-3 mb every three hours for half a day, until the pressure drop accelerates. Violent storms in their passage can cause a pressure drop of 5-10 mb in 3 hours, but the record drops belong to the passage of the eye of a tropical storm - up to 12 mb per hour!
It is important to know what pressure drop can be dangerous for him. Remember the 4-5-6 rule. It means: a pressure drop of 4 or 5 mb in 6 hours is a signal for a change in the weather for the worse ...

From Weather Trainer by David Burch
Translation by S.Svistul

The physical essence of atmospheric pressure will be described in detail in the article “Where does the wind come from”.

Barometer - a device that measures the readings of air pressure on surrounding objects, was invented in the 17th century by the outstanding Italian scientist E. Torricelli. Initially, it looked like a glass tube with marks, inside it was filled with mercury. At the time of the study, the mercury column was at 760 mm, now this figure is considered to be the level normal pressure, by which they judge whether the pressure rises or vice versa decreases. A device of this type, due to its high degree of accuracy, is now used at various meteorological stations and in scientific laboratories.

After 2 centuries, after great amount tests and using the achievements of the outstanding German scientist Jacob Leibniz, engineer-inventor from France Lucien Vidi revealed to the world his "brainchild" - an improved aneroid barometer (from the Greek "aneros" - "without moisture"), which was much safer to use and had more a light weight.

To date, there are such varieties:

• Liquid barometers;
• mercury;
• Aneroid barometers;
• Electronic.

The principle of operation of the barometer

Externally, a liquid barometer has the form of glass tubes interacting with each other as communicating vessels in accordance with hydrostatic laws. Fill them with mercury or other light weight liquids (glycerin, oil).

cup barometer

Cup - a glass tube with a closed end and a cup, pressure readings are determined by measuring the height of the column of liquid, which starts from the level of the cup and ends with the mark of the upper meniscus.

Siphon barometer

Siphon - a tube with a closed long end, siphon-cup - two tubes, one in open form, the other in a closed + cup, in which the air pressure readings are set by determining the difference in the levels of the liquid column in the first and second tubes.

mercury barometer

A mercury barometer is a pair of communicating vessels, inside is mercury, the top of one glass tube, about 90 cm long, is closed, there is no air. Depending on changes in pressure, mercury rises or falls in the glass tube under the influence of air, and a small float shows the movement of the mercury mass and stops at a mark showing its level in millimeters. The norm is mercury at around 760 mm Hg. Art., readings above this value - there is a process of increasing pressure, below - lowering. Barometers of this type are practically not used in everyday life, because mercury is a dangerous toxic substance, the design of the barometer is rather cumbersome and requires careful handling. Therefore, they are widely used only in laboratory conditions, at various scientific meteorological stations and in industry, where the absolute accuracy of data transmission is important.

Classic aneroid barometer

(1 - body; 2 - corrugated hollow metal box; 3 - glass; 4 - scale; 5- metal flat spring; 6 - spiral spring; 7 - thread; 8 - transmission mechanism; 9 - pointer arrow)

The system of operation of a mechanical aneroid barometer, in which there is no liquid, is based on the principle of the effect of air pressure on metal. In the middle of the device there is a box with thin corrugated metal walls, under the force of air the walls are compressed or unclenched, the lever turns the arrow in one direction or another. There are wall and desktop types, they are very convenient and practical to use, so they are very often used at home, in offices and various institutions.

Electronic barometer

An electronic (or digital) barometer is a modern version of this device, the linear indicators of a conventional aneroid barometer are converted into an electronic signal, which is processed by a microprocessor and displayed on a liquid crystal screen. It has compact dimensions, is simple and convenient to use, for example, for fishing, tourism or as a country option.

At the moment, there is already a digital version of barometers, which are built-in as an additional function in a mobile device or in barometer watches.

BAROMETER
a device for measuring the pressure of atmospheric air. Pressure is the force acting per unit area of ​​a surface. Earth atmosphere, extending hundreds of kilometers upward, exerts pressure on the surface of the Earth; The barometer is used to measure this pressure. Atmospheric, or barometric, pressure is measured in millimeters of mercury and in pascals (see below). Changes in atmospheric pressure are usually associated with changes weather conditions. Pressure usually falls before a storm, and its increase portends good weather. By marking changes in pressure on a map, one can determine the direction of winds and the movement of cyclones. Lines of equal pressure are called isobars from the Greek. isos (equal) and baros (weight). Barometers were adapted to measure altitude, as atmospheric air pressure decreases with increasing altitude. Aircraft are equipped with such devices (altimeters), climbers take them with them. There are two main types of barometers - mercury and aneroid. The mercury barometer is more accurate and reliable than the aneroid. Aneroid is more compact and convenient, it can be made pocket-sized.
Mercury barometer. A mercury barometer shows atmospheric pressure as the height of the mercury column, which can be measured on a scale attached to the side. In its simplest form (Fig. 1), it is a mercury-filled glass tube approx. 80 cm, sealed at one end and open at the other, immersed with the open end in a cup (sometimes called a cistern) of mercury. There is no air in a barometric tube, and the space at the top of the tube is called the Torricellian void.

Rice. 1. MERCURY BAROMETER. The simplest mercury barometer (left) is a mercury-filled glass tube with its open end dipped into a cup of mercury. The mercury in the tube rises and falls as the weather changes. In the siphon barometer (middle), changes in the mercury level at the open end of the tube are transmitted by means of a weight W with a counterweight C to an arrow that points to the inscriptions on the dial that predict the weather. The Fortin barometer (on the right) is a cup barometer in which the zero of the scale is set by turning the screw A until the bone point T touches the mercury surface; For a more accurate reading on the scale, a vernier (vernier) is provided.

To make a mercury barometer, you must first fill the tube with mercury. Then, holding the open end with your index finger, immerse this end in the mercury in the cup. As soon as you remove your finger, the mercury in the tube will drop so that the pressure of its column will be balanced by the atmospheric pressure acting on the surface of the mercury in the cup. After that, atmospheric pressure can be measured as the height h of the mercury column that it balances. When the atmospheric pressure changes, the height of the column will change. The average atmospheric pressure is 760 mm Hg. (1 mm Hg = 133.3 Pa).
Aneroid. There is no liquid in the aneroid (Fig. 2) (Greek "aneroid" - "anhydrous"). It shows the atmospheric pressure acting on a corrugated thin-walled metal box in which a vacuum is created. With a decrease in atmospheric pressure, the box expands slightly, and with an increase, it contracts and acts on a spring attached to it. In practice, several (up to ten) aneroid boxes are often used, connected in series, and there is a lever transmission system that turns the arrow moving along a circular scale calibrated by a mercury barometer. As with the siphon mercury barometer (Fig. 1), the aneroid scale can be labeled ("rain", "variably", "clear", "very dry") to indicate weather conditions.

The aneroid is smaller than a mercury barometer and easier to read. It can be used in expeditionary conditions, on ships, aircraft, etc. If you attach a pen to its arrow, it will record readings. Such barographs, i.e. aneroids recording barometric pressure are available at all weather stations.
LITERATURE
Kedrolivansky V.N., Sternzat M.S. meteorological instruments. L., 1953 Gaevsky N.A. Pressure measurement technique. M., 1970 Osadchiy E.P. Designing sensors for measuring mechanical quantities. M., 1979 Fedyakov E.M. and other Measurements of variable pressures. M., 1982

Collier Encyclopedia. - Open society. 2000 .

Synonyms:

See what "BAROMETER" is in other dictionaries:

Barometer ... Spelling Dictionary

barometer- well. barometer m. 1. A device for measuring atmospheric pressure. BAS 2. A barometer is called a tool, with its help the gravity of the Atmosphere can be known. CH 109. The barometer soon rose to the top. Ledyan. House 32. Ponezhe Imp. led. was willing to order ... ... Historical Dictionary of Gallicisms of the Russian Language

- (from the Greek. baros heaviness, and metron measure). An instrument that determines the measure of air pressure and can therefore, to some extent, predict the weather. Vocabulary foreign words included in the Russian language. Chudinov A.N., 1910. BAROMETER from Greek ... ... Dictionary of foreign words of the Russian language

BAROMETER, a device for measuring ATMOSPHERIC PRESSURE. There are two main types of barometers: the mercury barometer and the aneroid; the latter is less accurate, however, commonly used in barographs and in household use. The mercury barometer consists of a glass ... ... Scientific and technical encyclopedic dictionary

BAROMETER- (from Greek baros gravity and metron measure), a device for measuring atmospheric pressure. atmospheric air has a certain weight and elasticity and its own, it exerts mass. pressure on all objects that have direct or indirect with it; new contact... Big medical encyclopedia

- (barometer obsolete), barometer, male. (from the Greek. baros heaviness and metron measure). A device for measuring atmospheric pressure. Barometers are mercury and aneroid. Explanatory Dictionary of Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary of Ushakov

- (Barometer) a device for measuring atmospheric pressure (air pressure). At meteorological stations, mercury bombs are used, which consist of a tube filled with mercury sealed at the top and immersed with the open end in a cup filled with mercury. The greater the pressure ... ... Marine Dictionary

barometer- Absolute pressure gauge for measuring the pressure of the near-Earth atmosphere. Note A barometer with continuous readings is called a barograph. [GOST 8.271 77] Pressure measurement topics EN barometerpressure indicator DE… … Technical Translator's Handbook

Barometer- The barometer portends imminent changes in affairs that will turn out to be very positive. If the barometer is broken, brace yourself for trouble... Big universal dream book

BAROMETER- (from the Greek "baros" gravity and "metreo" I measure) a device for measuring atmospheric pressure. Usually they use a metal aneroid barometer, in which a hermetically sealed metal box changes its shape under the action of an external ... ... Brief Encyclopedia household

Barometer- - absolute pressure gauge for measuring the pressure of the near-Earth atmosphere. Note. A barometer with continuous readings is called a barograph. [GOST 8.271 77] Term heading: Devices Encyclopedia headings: Abrasive equipment ... Encyclopedia of terms, definitions and explanations of building materials

Barometers can be aneroid and mercury. The word "aneroid" means "liquidless". The principle of operation of such a barometer is quite simple: changes in atmospheric pressure lead to a change geometric dimensions aneroid, as a result, the arrow on the scale moves. Such barometers do not contain dangerous elements, therefore they are suitable for use on a hiking trip.

In addition to aneroid, there are also devices in which mercury is used to measure atmospheric pressure. Under the action of atmospheric pressure, the height of the mercury column changes. The readings of these barometers are more accurate; these are the instruments used at meteorological stations. Mercury and its vapors are dangerous to humans, therefore, such devices are not used in conditions.

On sale you can find electronic barometers, as a rule, they are part of home weather stations. Such integrated instruments also measure a number of other quantities (for example, air temperature and humidity) and make it possible to fairly accurately predict the weather for the near future. Digital devices less sensitive to shaking, so they are good to use in sea travel.

Using the barometer

An aneroid barometer is easy to use. You need to look at what value the arrow of the device points to. There are zones on the barometer scale, which are designated as “dry”, “clear”, “variable”, “rain”, “storm”, as well as divisions indicating absolute values. If the pressure decreases, precipitation is expected, if it rises, it will be clear. As a rule, the barometer has two arrows - one is movable, it is connected to the aneroid box, and the second can be rotated. If it is combined with an arrow showing the value of atmospheric pressure, after a while you can observe in which direction the movable arrow will deviate.

Normal atmospheric pressure is 760 mm Hg. Art. at an air temperature of 15°C at the so-called sea level. Home barometers can measure its value in the range of 700-800 mm Hg. Art. at an altitude of no more than 300 m above sea level. A drop in pressure means worsening weather conditions, approaching rains or snowfalls. Low pressure areas are called cyclones. Anticyclones are areas with high blood pressure, their approach means the onset of good weather. The barometer is adjusted if its readings differ from the readings of the local weather station by more than 8 mm Hg. Art. For these purposes, an adjustment screw is provided, located in the rear of the case. When setting up, you need to rotate it at an angle of no more than 45 degrees.

The invention of the barometer is universally credited to Evangelisto Torricelli in 1643. However, historical documents say that the first water barometer was unknowingly built by the Italian mathematician and astronomer Gasparo Berti between 1640 and 1643.

Gasparo Berti's experiment

Gasparo Berti (circa 1600 - 1643) was most likely born in Mantua. He spent most of his life in Rome. He became famous for the experiment in which he, without knowing it, built the first working barometer. He also has works in mathematics and physics.

In 1630, Giovani Battista Baliani sent a letter to Galileo Galilei saying that his siphon-type pump could not lift water more than 10 meters (34 feet). In response, Galileo suggested that vacuum lifts water, and the vacuum force cannot hold more water, just as a rope cannot hold too much. big weight. According to the ideas prevailing then, a vacuum could not exist.

Galileo's ideas soon reached Rome. Gasparo Berti and Rafael Maggiotti developed an experiment to test the existence of a vacuum. Bertie built an 11-meter pipe, filled it with water and sealed it on both sides. Then one end was immersed in a container of water and opened. Part of the water flowed out, but about ten meters of the pipe remained filled, as Baliani had predicted.

The space above the water had to look for explanations. Explanations within the framework of the prevailing theory that rejects the vacuum, there were as many as two. According to the first, water gives birth to "spirits". "Spirits" fill space and displace water. According to the second, more common argument proposed by Descartes, the space above water is filled with ether. Ether is such a thin substance that it can penetrate through the pores in a pipe and displace water.

Explanation of Evangelisto Torricelli

Evangelisto Torricelli, a student and friend of Galileo, dared to look at the problem from a different angle. He suggested that air has weight, and that it holds the water in the pipe at a level of about ten meters. Previously, it was believed that air is weightless and its thickness does not exert any pressure. Even Galileo accepted this statement as an infallible truth.

If the assumption about the weight of air is correct, a liquid heavier than water should sink lower in the pipe than water. Torricelli shared this prediction with his close friend Vincenzo Viviani and suggested using it as a

A barometer, or anerograph, is needed for fishing by a fisherman in order to measure atmospheric air pressure with it, which, in turn, affects the size of the catch. In other words, with the help of a barometer, a fisherman can accurately determine which day there will be a good bite. If within three days the barometer readings are approximately at the same mark, feel free to go fishing! The catch is guaranteed! If the pressure has changed by 7-8 points during the day, it is useless to fish today. Did the pressure change while fishing? Change location. If the pressure value has increased, then the fish has risen to the surface.

The barometer monitors even the slightest changes in the weight of the atmospheric column, which is indicated by an arrow. To take readings, you just need to compare the shift of the pointer arrow with its previous value. A rapid decline means an imminent storm. A constant increase in warm sunny weather.

The influence of atmospheric pressure on the behavior of fish

Different types of fish react to changes in the weight of the atmospheric column in different ways. Predators, for example, with a decrease in pressure, begin to actively hunt and feed. An increase in pressure, on the contrary, affects them negatively. This is actively used by such fish as white salmon and other peaceful fish. In the absence of a threat from predatory species, they actively move and look for food.

The most negative effect on the results of fishing is a sharp change in atmospheric pressure (both upward and downward). During such drops, the fish is in a "suspended state", and practically does not react to any bait.

A good interest in food and, therefore, a good biting in the ichthyofauna is observed before the onset of a cold weather front or before a gusty wind, which may be associated with a premonition of worsening weather conditions.

Fishing barometers

Among the variety of designs for fishing, two main categories can be conditionally distinguished:

• household;
• Pocket.

The former are mainly used in an apartment or house. When fishing, such a device can be placed on a table or wall of a fishing house located near the coastline. In this case, it is necessary to have access to fresh air. The accuracy of a measurement taken in a tight indoors, will be noticeably lower.

Pocket devices are more compact, they can be placed on a wristband or in a fisherman's pocket.

Such a device can be taken directly to the shore, to the place of fishing.

According to the principles of the device, pressure meters are divided into mercury, mechanical (or aneroid barometers) and electronic (digital) devices.

• Mercury anerographs are as accurate as possible. They are widely used in weather stations. But they are completely unsuitable for use in fishing, as they contain a large amount of mercury and can be dangerous.
• Aneroids are somewhat less accurate, but much less brittle and safer. In addition, they have a presentable appearance.
• Electronic devices are a high-tech product. They are light and compact, and in addition, they have a very wide functionality. These devices are often real weather stations in miniature and allow you to measure not only the dynamics of pressure fluctuations, but also temperature, altitude, humidity and a number of other parameters.

How to choose a barometer for fishing

The barometer is a complex instrument and there are several things to consider when choosing this device.

1. Often the reason for the low accuracy of the instrument readings is poor build quality and a variety of errors when installing the mechanism. To avoid voiding your warranty, do not repair the mechanism yourself. It is better to try to immediately select a workable device.
2. When choosing a mechanical barometer in a store pay attention to the position of the adjusting screw. It is located on the back cover of the instrument case. The closer it is to the hole under it, the better. If the screw is not located coaxially, then the entire mechanism of the device is skewed and you should not hope for measurement accuracy.
3. Looking inside the mechanism pay attention to the size of the bellows. The accuracy of the anerograph readings is directly related to its size.
4. Examine the barometer from all sides. Pay attention to the dial (clearness and sufficient size of the numbers), the quality of the glass (the absence of unnecessary glare and reflections).
5. An important requirement when choosing a device for fishing is waterproof. No matter how you take care of your device, the risk of swimming is very real. Yes, and unplanned bad weather can cause moisture to enter the case.
6. impact resistance- also an important characteristic, especially for a pocket and wrist barometer. On a slippery shore, it is easy to slip and hit the device on a stone or tree.
7. When choosing a digital weather station or multi-function watch, it is advisable to develop a list of features that you will need. This will help you choose the right weather model and not overpay for unclaimed functionality.
8. If you prefer night fishing also check the backlight of the dial or display.
9. For wrist devices, it is also important secure strap or bracelet. There is nothing more offensive than losing an expensive item due to an unfastened or torn strap.
10. The trident of the mechanism is installed in the center of the barometer scale. When the instrument reads 750 mm. all parts of the trident must be parallel. This means that the arrow is set correctly and has not gone astray relative to the mechanism of the device.
11. In some types of barometers, not only a thermometer is built-in, but also a hygrometer. Special devices designed for fishermen have special scales on which, in addition to marking the pressure in mm. rt. Art. there are notes about the state of the weather: "Clear", "Variably", "Rain". In some modifications, a special bite scale is applied to the dial.
12. remember, that any barometer requires calibration and verification, like any other measuring device. Verification and initial installation of the anerograph can be done according to the readings of the city weather station. To set the readings, use the adjusting screw on the back of the barometer. Please note that you can rotate it no more than 45 degrees in any direction, otherwise there is a risk of damage to the mechanism.

How to increase the catch of fish?

For 7 years of active passion for fishing, I have found dozens of ways to improve the bite. Here are the most effective ones:

1. Biting activator. This pheromone additive lures fish the most in cold and warm water. Discussion of the Hungry Fish bite activator.
2. Raise gear sensitivity. Read the appropriate manuals for the particular type of tackle.
3. Lures based pheromones.

Popular barometer models

PB-8(anerograph, thermometer, hygrometer). This device is a complex of three main meteorological instruments. The mini weather station is produced in wooden case, mechanism material – brass. The weight of the device is 1.4 kg. Price - 3770 rubles.

The Swedish-made mechanical pressure gauge has stylish design and shows very high precision measurements (provided by manual assembly). Price - 2980 rubles.

Belongs to the class of compact wall-mounted meteorological instruments. It is a complex of anerograph, hygrometer and thermometer. The error in the accuracy of measuring atmospheric pressure at this station does not exceed one millimeter of mercury. The price in various trade organizations and online stores ranges from 1950 to 2500 rubles.

Reliable and relatively affordable weatherman made in Sweden. Equipped with a built-in thermometer, has a very low measurement error - only 0.3 mm Hg. Art. The price varies in the range from 1700 to 2000 rubles.

An electronic device jointly produced by Sweden and China allows measuring the dynamics of atmospheric pressure and air temperature, as well as recording readings. The bright orange plastic case makes the device noticeable and will not let you lose it on the shore. Price - 2883 rubles.

Wristwatch with barometer SUNROAD FX 702. Complex of measuring instruments includes clock, barometer, stopwatch, altimeter and thermometer. The watch is enclosed in a waterproof case, has a dim, economical display backlight. There is a function of recording a pressure change diagram, as well as notification with an audible signal. Weight - 55 gr. Price - 4200 r.

It has a pressure measurement range from 695 to 805 millimeters of mercury. The temperature range is from +10 to +50 degrees Celsius. Cost - 1250 rubles.

How to make a barometer with your own hands

Not everyone has the opportunity to buy a barometer in a store. However, a fully functional device for measuring fluctuations in atmospheric pressure can be constructed at home from available materials.

You will need:

• Transparent bottle with a capacity of 0.5 liters.
• A glass tube about half the inside diameter of the bottle neck. The length of the tube should be equal to the height of the bottle.
• Plasticine for fixing the tube.
• Distilled water to fill the barometer.

Fill the bottle with distilled water one third of the volume. Place the glass pipe inside the bottle so that it is 2-3 centimeters from the bottom and protrudes from the neck to the same height. To prevent it from slipping, tightly cover the neck of the bottle with plasticine. For ease of observation, the water can be slightly tinted, for example, with a drop of brilliant green.

After manufacturing, a home-made instrument for measuring pressure needs a period of a couple of months for self-regulation. At this time, it is highly undesirable to allow direct contact with it. sun rays. It will also be useful to maintain in the room where it is stored homemade device, constant temperature. In this case, he will begin to give correct testimony much faster.

Good weather can be expected if the tube is completely filled with air. But if liquid oozes through it - expect inclement weather!
Another simple and original design uses the property of a pine cone to open in clear weather and close before rain.

To make the device, glue two small boards at a right angle. On the upper edge of the horizontal board, draw a scale with the image of a cloud and the sun. Fix a dry cone on the edge of the base, after gluing a light, dry blade of grass to one of its scales. To calibrate the device, observe it for 1 - 2 months, following the same rules as in the previous instructions.

1. Atmospheric pressure measurements must be taken at the same altitude to avoid charting errors.
2. Every 12 meters of height gives a measurement error of 1 mmHg. Therefore, do not be surprised if your barometer shows different readings in the apartment on the 16th floor and on the lake.
3. If the banks of the reservoir are steep and steep, try to take pressure measurements near the water's edge line, because you will catch it there! And the difference in height can distort the readings.
4. Do not forget that each body of water is unique in its depths, bottom topography, currents and many other factors. Therefore, it is not surprising that observations that are valid for a lake may not be justified when fishing in a river backwater or near a rift.
5. When predicting bite, keep in mind that different types fish react to pressure changes with different intensity. As a rule, the reaction of bottom fish is less pronounced. Peaceful fish endure fluctuations in atmospheric pressure much more painfully than predatory ones.
6. When fishing for pike at high pressures, it is worth putting smaller lures. Experienced anglers manage to catch even very large pikes! This is explained by the fact that the predator high pressure does not want to chase large fish, and evaluates small bait as easy prey.

Good luck to you!