How to use a barometer to find out what pressure is. Barometer is a device for measuring atmospheric pressure. Features of data interpretation

Barometer is a measuring device that is designed to determine atmospheric air pressure. In addition to meteorological applications, the barometer is used for environmental monitoring (for example, to certify workplaces) or in aviation (to determine flight altitude above sea level).

Figure 1. Aneroid barometer

For the first time, the barometer was invented and described in the work “Opera geometrica” in 1644 by a scientist from Florence (Italy) Evangelista Torricelli. It was a liquid mercury barometer, the pressure of which was measured by the height of the mercury (liquid) column in a tube sealed at the top and placed at the lower end in a vessel with mercury (liquid). On the day that Torricelli conducted the experiment with his mercury barometer, the weather was calm and sunny, and the mercury column stood at 760 mm. Since then, a pressure of 760 mmHg has been normal. Mercury and liquid barometers are the most accurate and are still used at weather stations. Their disadvantages are fragility, insecurity and large size.

In 1844, the French engineer Lucien Vidy, using the research of a German mathematician and physicist of the 17th century. Gottfried Wilhelm Leibniz, designed a fundamentally new, liquid-free barometer, which was called an aneroid barometer (from the Greek “aneros” - not containing moisture). Barometers built on the basis of the L. Vidi barometer are currently the most common.

At all, barometers, depending on the principle of operation may be mercury, liquid, aneroid or electronic.

- Liquid barometer- a device that uses the principle of balancing the weight of a liquid column with atmospheric pressure.

- Mercury barometer- atmospheric pressure, which can be measured by the height of the mercury column on a scale attached next to it.

- a device whose operating principle is based on changing the dimensions of a metal box filled with rarefied air under the influence of atmospheric pressure. Such barometers are reliable and small in size.

- Electronic barometer– this type of barometer works on the principle of converting the linear dimensions of a traditional aneroid pressure box into an electrical signal and further processing this signal by a microprocessor. If, instead of an aneroid box, a strain gauge is used, then the measured pressure is perceived by this sensitive element and is converted through its deformation into a change in the electrical resistance of the strain gauges of the strain gauge transducer.

However, since the topic of this article is “Barometer-Aneroid,” we will return to this type of pressure measuring devices and consider them in more detail.

So, this is a device that is intended to measure atmospheric pressure mechanically. Structurally, the aneroid consists of a round metal (nickel-silver or hardened steel) box with corrugated (ribbed) bases, in which a strong vacuum is created by pumping out air, a return spring, a transmission mechanism and an indicator needle. Under the influence of atmospheric pressure: its increase or decrease, the box, respectively, either compresses or unbends. In this case, when the bellows box is compressed, the upper flexing surface begins to pull the spring attached to it down, and when the atmospheric pressure decreases, the upper part, on the contrary, bends and pushes the spring upward. An indicator needle is attached to the return spring using a transmission mechanism, which moves along a scale calibrated in accordance with the readings of the mercury barometer (Figure 2). It is worth noting that usually, in practice, several (up to 10 pieces) thin-walled corrugated boxes with vacuum are used in series, which increases the amplitude of the pointer moving along the scale.

Figure 2. Aneroid Barometer structure.

Aneroid barometers, due to their small size and the absence of liquid in their design, are the most convenient and portable; they are widely used in practice.

Unfortunately, barometers are affected by ambient temperature and changes in spring tension over time. Therefore, modern aneroid barometers are equipped with an arc-shaped thermometer, or a so-called compensator, which is intended to correct the instrument readings for temperature.

In general, to obtain the true value of atmospheric pressure, the readings of an aneroid barometer require various corrections, determined by comparison with a mercury barometer. There are three amendments to aneroids:

Scale correction - this correction depends on how unevenly the aneroid barometer reacts to pressure changes in different parts of the scale,

Temperature correction - determined by the relationship between temperature and the elasticity of the aneroid corrugated box and spring,

The amendment is additional - determined by a change, over time, in the elasticity of the aneroid corrugated box and spring.

The body of an aneroid barometer is usually made of valuable types of wood, such as walnut, oak, beech, cherry or mahogany. Such barometers are no longer just instruments for measuring atmospheric pressure, but interior items. However, to reduce the cost of the entire structure and make it more practical, the aneroid body can be made of plastic or metal.

Aneroid barometers presented by models:

- BAMM-1 is a barometer, which is intended for measuring atmospheric pressure in ground conditions and indoors. Included in the State Register of Measuring Instruments of the Russian Federation, therefore it can be used for certification of workplaces.

- M-67 is the most accurate and unpretentious barometer. Thanks to its design features, it is capable of operating at temperatures from -10 to +50 o C (Figure 3).

- M-110 – barometer for industrial use, included in the State Register of Measuring Instruments.

- BB-0.5M – household wall-mounted barometer. Ideal for approximate measurements of atmospheric pressure.

- BR-52 – a school aneroid barometer, used as a teaching aid and for conducting experiments.

Figure 3. Barometer model M67.

To carry out more accurate or longer-term measurements, as well as to verify related instruments at weather stations, weather posts and laboratories, other instruments are used. They can be either digital or mechanical. For example, the BOP-1M barometer, being an exemplary portable barometer, as a reference measuring instrument, is intended for checking barometers of various designs and devices for general industrial purposes that measure atmospheric pressure.

BRS-1M is a working network barometer, designed to accurately determine absolute air pressure, has a digital RS232 interface for connecting to a computer.

Meteorological barograph M-22A is a device that is intended for determining and graphically recording atmospheric pressure values ​​both indoors and outdoors, for a certain period of time (Figure 4.).

Figure 4. Barograph M-22A

The MD-13 automated digital barometer is used at weather stations for long-term (up to 1 month) measurement of atmospheric pressure with the ability to transfer measurement results to a computer.

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

In addition to aneroid devices, there are also instruments that use mercury to measure atmospheric pressure. Under the influence of atmospheric pressure, the height of the mercury column changes. The readings of these barometers are more accurate; these are the devices that are used at meteorological stations. Mercury and its vapors pose a danger to humans, so such devices are not used in such conditions.

Electronic barometers can be found on sale; as a rule, they are part of home weather stations. Such complex devices 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 are less sensitive to shaking, making them good for sea voyages.

Using the barometer

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

The normal atmospheric pressure is 760 mm Hg. Art. at an air temperature of 15°C at so-called sea level. Home barometers can measure its value in the range of 700-800 mmHg. Art. at an altitude of no more than 300 m above sea level. A drop in pressure means worsening weather conditions, approaching rain or snowfall. Areas of low pressure are called cyclones. Anticyclones are areas of high 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, there is an adjusting screw located in the rear of the housing. When setting, you need to rotate it at an angle of no more than 45 degrees.

Since childhood, we have been accustomed to hearing about high or low atmospheric pressure, but we did not understand how to determine it, and why it is high or low. In today's article we will take a closer look at the device, the purpose of which is to solve the problem of determining these parameters.

Peculiarities

An aneroid barometer is a household device designed to monitor atmospheric pressure differences mechanically. This device is very sensitive and can show the difference in pressure even when going up in an elevator. When observing its indicators, you can notice certain changes when the weather changes. Thus, many changes can be predicted: before the weather turns bad, atmospheric pressure decreases, and before the arrival of a clear day, it increases.

Before taking readings from the device, it is necessary to take into account the height of its location above sea level. The higher the device is, the lower the atmospheric pressure will be. When rising to a slight height, the readings will be reduced by 1 mm Hg. Art. approximately every 12 meters of ascent.

The aneroid barometer has one drawback - it effect of air temperature on the spring. The difference in temperature readings causes the metal to contract when cold and expand when heated without changing atmospheric pressure. To correct for temperature, modern models are equipped with compensating thermometers.

Thanks to them, corrections can be made to the instrument readings.

Operating principle and device

The described device consists of a round metal box made of hardened steel (sometimes of nickel silver). The ribs of this part have a corrugated coating. This is necessary to impart rigidity to the structure, since a highly discharged environment is created inside by vacuuming. In such conditions, the return spring and the arrows of the mechanism are constantly present.

When atmospheric pressure acts on the walls of the device, contraction or expansion occurs. During such compression, the upper platform begins to bend and pull the spring attached to it down. When the load decreases, the upper half of the platform, on the contrary, bends upward and puts pressure on the spring. An arrow is attached to the return spring part through a return mechanism, which moves along a value scale.

To obtain the most accurate readings, it is necessary to make comparisons with the values ​​of a mercury barometer. There are 3 main corrections for mercury:

• on a scale, namely, to unequal responses in different zones of the scale;
• by temperature– the error for the physical change of the metal when exposed to temperature is taken into account;
• other errors, which are caused by changes in the elasticity and rigidity of metal parts over time.

The scale is lined in accordance with the values ​​of the mercury barometer. Using the barometric formula, you can calculate the altitude at which the device is located. By measuring the atmospheric pressure at the upper and lower measured points, it will be possible to determine the difference in pressure and convert it into meters. This measurement method is called barometric leveling. In this way, the height of the observation point is calculated in GPS devices.

Varieties

This device was first described in 1644 by a scientist from Italy, Evangelist Torricelli. This device turned out to be the first mercury (liquid) barometer, the values ​​of which were measured in accordance with the height of the mercury column. The design of such a device is very simple. The glass pillar has a sealed top, and its bottom is immersed in a container with mercury. During the experiment, the weather outside was very good and clear. Then the mercury column froze at a height of 760 mm, which was subsequently taken as the optimal indicator.

Mercury models are used in our time at meteorological stations because they have high accuracy, and with it the disadvantages of unsafety, fragility of design and bulkiness.

Today it is a control device by which all other devices are configured.

In 1844, French engineer Lucien Vidy, based on the work of physicist and mathematician Gottfried Wilhelm Leibniz from Germany, created another type of barometer that operated without liquids. This “liquidless” device was later called an aneroid barometer.

The aneroid version is by far the most common among household versions.

There are 4 types of such devices:

• liquid– this device uses the principle of equalizing the mass of a liquid column with the surrounding pressure;
• mercury– atmospheric pressure is measured due to the height of the mercury column with a scale attached to it;
• aneroid barometer – the device operates on the principle of changing the size of a box with a rarefied medium inside; under the influence of atmospheric pressure, its size changes;
• electronic barometer- this subtype of barometer uses the conversion of changes in the aneroid barometer box into a digital signal or using a strain gauge transducer, which is very sensitive, and a change in atmospheric pressure is perceived as deformation, as well as a change in resistance.

Let's consider models of aneroid barometers.

• BAMM-1. This device is designed to measure atmospheric influences on the ground and indoors. This type is included in the State Register of Measuring Instruments and can be used to check workplaces.

• M-67. The device has more accurate readings, and due to its design features, the operating temperature range is from -10 to +50 C.

• M-110. This barometer is intended for industrial use.

• BB-0.5M. A household appliance designed to be placed on the wall is well suited for weather-sensitive people to monitor changes in atmospheric pressure.

• BR-52. The school aneroid barometer is designed in such a way that it can be used for experiments.

How to use?

When taking readings from the described device, you must understand that it does not provide a 100% guarantee of weather changes or the amount of precipitation. It will not show which atmospheric front came to the area being checked. Meteorologists use many additional instruments and images to determine the weather.

The device itself only gives an idea of ​​the direction in which weather conditions will change. It will show whether the weather will be changeable for the worse or for the better. The device is necessary for weather-sensitive people to control their own well-being:

• during the cold winter season when the pressure drops, you can expect frost, and when the pressure rises, warming and possible snowfall are expected;
• in summer time An increase in pressure indicates the approach of hot and dry days, and a decrease warns of the approach of rain.

The rate of change in values ​​is also regarded as the most likely change in the weather. And when the pressure decreases gradually, then the weather will worsen during the day. Wind and precipitation possible. If the needle drops sharply, strong winds and heavy rain with thunderstorms should be expected.

A sharp drop in the needle can also indicate its onset in about 2 hours. When the needle freezes and remains at a certain level, then you can count on the wind decreasing and precipitation stopping.

To correctly understand the readings of the device, you need to constantly monitor it. In good weather, you can take all values ​​2 times a day, but in bad weather you need to monitor the device every 2-3 hours.

After the advent of the electronic barometer, the need to configure it disappeared, but there are still classic options on the market that require regular adjustments.

They are loved for their presentable appearance and the absence of the need to replace batteries.

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

In addition to aneroid devices, there are also instruments that use mercury to measure atmospheric pressure. Under the influence of atmospheric pressure, the height of the mercury column changes. The readings of these barometers are more accurate; these are the devices that are used at meteorological stations. Mercury and its vapors pose a danger to humans, so such devices are not used in such conditions.

Electronic barometers can be found on sale; as a rule, they are part of home weather stations. Such complex devices 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 are less sensitive to shaking, making them good for sea voyages.

Using the barometer

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

The normal atmospheric pressure is 760 mm Hg. Art. at an air temperature of 15°C at so-called sea level. Home barometers can measure its value in the range of 700-800 mmHg. Art. at an altitude of no more than 300 m above sea level. A drop in pressure means worsening weather conditions, approaching rain or snowfall. Areas of low pressure are called cyclones. Anticyclones are areas of high 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, there is an adjusting screw located in the rear of the housing. When setting, you need to rotate it at an angle of no more than 45 degrees.

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

Gasparo Berti's experiment

Gasparo Berti (c. 1600 - 1643) was most likely born in Mantua. He spent most of his life in Rome. What made him famous was an experiment during which he, without knowing it, built the first working barometer. He also has work in the fields of mathematics and physics.

In 1630, Giovanni Batista Baliani sent a letter to Galileo Galilei saying that his siphon-type pump could not lift water to a height of more than 10 meters (34 feet). In response, Galileo suggested that water was lifted by a vacuum, and the force of the vacuum could not hold more water, just as a rope could not support too much weight. According to the prevailing ideas at that time, a vacuum could not exist.

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

The space above the water had to be explained. There were two explanations within the framework of the prevailing theory that rejected the vacuum. According to the first, water gives birth to “spirits”. “Spirits” fill the space and displace water. According to the second, more common argument, proposed by Descartes, the space above the water is filled by the ether. Ether is such a thin substance that it can penetrate the pores in the pipe and displace water.

Explanation by Evangelisto Torricelli

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

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

In the seventeenth century, the fact that air has a certain weight became known and proven to humanity. The assumption of its pressure on various objects was proven using a special device - a barometer. It will be discussed in this article.

A device that determines air pressure

First, let's give a definition. A barometer is a device for measuring a certain air pressure on objects. Its inventor was E. Torricelli. In 1644, the barometer was a tube containing mercury and a measuring scale. On the day when the barometer was tested, the mercury level was at 760 mm, which was the reason to consider the mark at this level to be normal pressure. Such instruments are still used by meteorological stations.

Two centuries later, after the invention of the mercury barometer, as a result of many studies, Lucien Vidy constructed a fundamentally new liquid-free type. Subsequently called the aneroid barometer. Throughout their existence, aneroids have gained great popularity among many users, because they are small in size, lightweight and accurate. Compared to mercury barometers, aneroids are completely safe to use.

Types of barometers

Mercury is a device that measures pressure. The principle of operation is the movement of mercury relative to the applied scale.

Liquid - a device with which the pressure level is measured by balancing the weight of a liquid column with atmospheric pressure.

Aneroid barometer - the principle of operation and display of indicators is based on the change in the size of a sealed metal box filled with rarefied air under the influence of atmospheric pressure on its surface.

Electronic is a modern type of device that converts the linear indicators of a classic aneroid into an electronic signal. The signals processed by the microprocessor are displayed on the liquid crystal screen.

An aneroid barometer is the most common of the above instruments, due to its small size and the lack of liquid in the mechanism. Let's look at it in more detail.

The structure of the atmospheric barometer

• Round silver-nickel plate.
• Box with ribbed bases.
• Transmission mechanism.
• Return spring.
• Index arrow.

Atmospheric barometer - operating principle

When assembled, the aneroid is a box with various mechanisms. When a certain amount of air is pumped out of it, this creates a strong vacuum in the return spring, the indicator needle and the transmission mechanism between them. Under the influence of pressure, the walls of the “pressure chamber” contract or increase in size, and the index arrow begins to move relative to the measuring scale in the direction of increasing or decreasing pressure, respectively. At rest, the needle will be at 760 mm.

Self-recording barometer

Used to record meteorological data regarding fluctuations in atmospheric pressure. In other words, this is an improved aneroid barometer, with the addition of a clock mechanism to the pressure chamber, an apparatus that holds graduated paper and a drive needle that puts an ink line on the paper.

The depicted “drawing” on the paper of the device is called a barogram. During the operation of the barograph, in accordance with hourly indicators, the mechanism winds special paper on its base, along the surface of which an attached arrow with ink slides and marks the indicators of deviations in atmospheric pressure.

Indicators of pressure discrepancies are recorded continuously. For meteorologists, this is the main documented fact of weather changes in the near future. Depending on the size of the drum, the duration of recording can range from several hours to one week. The special design allows you to take readings and monitor atmospheric indicators at any time.

Barometer on your phone - what is it?

Technology does not stand still, and now you can measure atmospheric pressure using a mobile device. Many users of modern gadgets, faced with a new function, wonder: what is a barometer on their phone? A modern miniature weather station allows the phone user to constantly electronically check the level of atmospheric pressure. By tracking pressure indicators over a certain time, you can find out whether a cyclone or anticyclone is approaching. These indicators will be useful for people with increased sensitivity to sudden changes in pressure.

The capabilities of a mobile device don’t stop there. In electronic form, it shows altitude, geographic width and longitude, which, in turn, facilitates a quick search for the device and determination of its exact location. Thanks to GPS satellites, the process is fast and accurate. Mobile barometer is an accurate altimeter. The accuracy of determining the user's location is reduced to a radius of 3 meters. These are the devices that climbers use in the mountains. But they have gained great popularity in the aviation sector.

Barometer built into the watch

Appeared relatively recently. Few people know what this device is for, and most are wondering - a barometer in a watch, what is it?

Let's try to figure it out. The barometer in certain types of watches is presented in electronic or mechanical form. The electronic view is no different from submitting atmospheric pressure data and displaying it on the screen, like on a phone. A watch with a mechanical pressure display is a perfectly accurate mini-copy of an aneroid. The only difference is in the simplified display scale. The cost of barometer watches is quite high, but, as a rule, they are shockproof and waterproof.

"Non-standard barometer"

Thanks to its founders it is called Harvard. The economic barometer underlies the formation of econometrics. Predicts changes in market conditions, dynamics of supply and demand, etc. The Harvard Barometer is a description of empirical patterns and extrapolations from recent months of observation. They are based on a study of the dynamics of development of various economic indicators.

The development forecast was displayed graphically. Each curved line plotted on the graph displayed one or another indicator. For example, curve “A” displayed changes in average exchange rates (stock market); curve “B” displayed the index of wholesale prices and changes in trade turnover (production); curve “C” - reflected the rise or fall in the price of securities on the money market. In the ideal state of the chart, indicators “A” and “C” should coincide at the level of the maximum of the first unit and the minimum of the curve of the second unit.

Thanks to the leadership of W. Persons and W. Mitchell, the United States used this type of device until 1925. The Harvard Mitchell Barometer is the first powerful regulator and indicator of factors in the national economy of the country. Given the popularity and effectiveness of this construction and display of facts, this method has been adopted by many countries around the globe. But the prospect of development of many countries according to this ratio of indicators in the economy did not last long, because before and after the Second World War - in percentage terms they became irrelevant. The economies of all the countries that took part in the war were in complete decline, and to solve the problem of getting up from their knees, each country used its own methods to stabilize its own monetary currency. The old methods of raising indicators (getting out of the crisis) were not used at all, but the foundations laid by Mitchell became a precedent for the world economy.

Pressure gauge

It is worth noting another device that also measures pressure, not of air, but of gases and liquids - this device is called a pressure gauge. These two devices are very interconnected. The sum of the readings of the manometer and barometer is the absolute pressure, which has a higher value than atmospheric pressure.

Conclusion

In the modern world, a barometer is one of the main meteorological instruments. The marked indicators on paper help many people learn about upcoming changes in atmospheric pressure and, accordingly, prepare for them. This applies to a greater extent to hypertensive patients. A barometer is an optional item in the home, but it is desirable as an auxiliary element or in addition to the interior. The modern frame of this much-needed device allows it to fit into any interior design.

Columbus, of course, is not the only brand of weather stations in Russia. Their main difference is an attempt to create an interior decoration item from a traditionally applied instrument, previously presented in classical forms. A wide range of shades, decoration, the use of brass and aluminum - all this turns an ordinary weather forecasting device into a small masterpiece (a full-fledged element of the interior).

Why do you need a weather station at all?

We usually learn the weather from reports from the Hydrometeorological Center and do not always understand on what basis the final forecast is based. Having the Columbus weather station at our disposal, we can always ourselves, trusting our eyes, make our own personal weather forecast. This issue is covered more fully in the Columbus weather station passport.

Operating instructions for weather stations and barometers

1. Taking into account the height of the terrain when adjusting the barometer

During meteorological observations, all data on air pressure are correlated with altitude above sea level. To obtain comparable values, the influence of terrain altitude on air pressure is corrected (pressure decreases with altitude). The indoor barometer is adjusted so that it indicates air pressure relative to altitude. Therefore, before use, it is necessary to adjust the barometer to the appropriate height of the place of use. The principle of terrain height adjustment is that changes in air pressure are compensated by adjusting the instrument needle in the opposite direction.
At the factory, the barometer is set to the terrain altitude indicated on the packaging. Therefore, only in rare cases is it possible to operate the barometer without new adjustments.
The easiest way to properly adjust a barometer is to adjust it using an existing barometer in the area or by air pressure data reported in weather reports.
If the altitude of the place where the barometer is used is already known exactly, then the correction value can be calculated. This calculation is based on the following considerations: air pressure decreases with increasing altitude and the dependence: 1 mm of mercury per 10.7 meters of height difference.
Example:
Terrain height – 200 meters
Operating altitude – 40 meters
Height difference – 160 meters
It is required to move the needle by 160/10.7 = 15 mm Hg towards lower pressure to increase air pressure.

2. Adjustment screw

The pointer is moved by rotating the adjusting screw. It is made of brass and is located in the hole in the back wall. When making adjustments, always take the shortest path.

Since indoor air pressure is the same as outside, the barometer can be hung anywhere. However, it is not recommended to hang it on damp external walls or near heat sources. This is especially important for barometers, with which thermometers and hygrometers are combined.

Before each reading, lightly tap the glass. In this case, a slight friction of the barometer allows you to determine the trend in air pressure changes. A comparison can also be made if an additional arrow is aligned with the barometer needle each time after reading.

When the air pressure is 765 mm Hg or more, you can count on calm and dry weather, and the higher the air pressure, the more stable the weather. In summer the weather is mostly cloudless and warm, in winter it is frosty. However, with high humidity and westerly wind (for the European part of Russia), fog (especially in winter) and rain are possible.
-A slow and steady rise in the barometer readings should expect improved weather, while a slow decline means better weather.
-Rapid growth in unstable weather is often followed by a rapid decline and means continued instability, changing clouds, gusty winds and rain or hail.
-In winter, an increase in pressure indicates frost, a decrease indicates a softening of the frost and a thaw.
-Values ​​of 750 mmHg and below are often associated with heavy clouds and precipitation. If the air pressure drops significantly below 750 mm Hg, then strong winds or storms should be expected.
-In summer, a rapid drop in pressure with great heat means a thunderstorm.

6. Temperature and humidity in the living area

A person feels comfortable at a temperature in the range of 18-22 degrees and relative humidity in the range of 45-70%. Fluctuations in air humidity in a residential area are mostly insignificant, but humidity in winter usually drops to 25-40% (especially in rooms with central heating), which is associated with a large difference in the temperature of the room and outside. In this case, the air is very dry, and increased humidity can be provided using humidifiers.

7. Correction of indications on thermometers and hygrometers

Although the adjustment of dial thermometers and hygrometers is accurately checked at the factory, in some cases, for example: after strong shaking during transport, adjustment may be necessary. Corrective adjustment can be made using a screwdriver through the hole on the back cover. In this case, insert a screwdriver into the visible slot on the support of the measuring mechanism. We recommend making corrections only if reference measurements taken using several liquid thermometers or regenerated hair hygrometers or psychrometers show noticeable discrepancies.
You can verify the functionality of hygrometers and dial thermometers by breathing on them from the back. If the thread of the capillaries of a liquid thermometer is interrupted, it can be reconnected by shaking in the direction of the top of the capillaries or in the direction of the cup. This is best done by pre-heating slowly, causing the thread to move upward. In this case, the thermometer must be unscrewed from the frame.

Height of application area – no more than 300 meters above sea level
- pressure measurement range – from 695 to 805 mm Hg (927-1073 hectopascal)
- temperature measurement range – from minus 10 C to plus 50 C
- humidity measurement range – 0-100%

Instructions for handling Columbus weather stations

1. If it is necessary to label weather stations or attach a price tag, we kindly ask you to adhere to the following rules:
do not stick stickers on the wooden parts of the weather station housing;
do not use strong adhesives, including tape;
RECOMMENDED: to identify weather stations, stick a sticker on the back of the product.

2. Pay special attention to the packaging of weather stations. The original packaging protects the weather stations from scratches. We strongly recommend that you pack your weather stations in the following order:
wrapping;
plastic bag;
bubble film.

3. DO NOT use cleaning products not intended for wood. Pay special attention to the varnished parts of the case.

4. Since weather stations use glass, please use extreme care when unpacking/packing, displaying, and moving the weather stations. It is recommended to use special gloves when handling weather stations.

5. When placing weather stations in a display case, make sure that the weather stations are at the maximum distance from lighting fixtures (especially halogen lamps). The heat emitted by these luminaires may damage the coating of weather stations.

6. When packing and transporting weather stations with clocks, be careful not to leave the batteries in the case. This is due to the risk that the battery may leak.

Careful compliance with these conditions will help you provide the buyer with weather stations in perfect condition and avoid possible problems with the appearance and performance of the weather stations.

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Barometer - a useful and beautiful gift

What is a barometer and what is it for?

Barometer is a device for measuring atmospheric pressure. When the pressure drops, precipitation is expected; when the pressure rises, it will be clear. Of course, it is not difficult for a modern person to find out the weather forecast. But on different sites, predictions can differ significantly. And if at one you will be advised to take an umbrella with you for the next week, then at the other they will tell you to urgently buy sunscreen.

The barometer will allow you to make your own forecast, and in addition, it is a stylish element of the interior. A barometer looks especially appropriate in the office of a business person.

What types of barometers are there?

Barometers, which are used by professional weather forecasters to measure atmospheric pressure, are one thing, and household barometers are quite another. The latter do not require such pinpoint accuracy of measurements as the former, but, of course, a home barometer can easily predict the approach of a snow storm or the onset of sunny weather. On the other hand, household barometers are compact, beautiful, easy-to-use devices.

According to the principle of operation, barometers are either mercury or liquid-free (aneroids). The mercury barometer was invented by the Italian scientist Torricelli in 1643. From the very name of the device it is clear that it uses mercury for measurements. Under the influence of atmospheric pressure, the height of the column of mercury placed inside the barometer changes.

The readings of such a device are accurate; mercury barometers are used at meteorological stations, but mercury poses a danger to humans. More precisely, the mercury vapor that is formed if the device is broken is dangerous. The same applies to an ordinary thermometer, familiar to us all from childhood, but it is still used in everyday life. But as for barometers, the use of mercury devices for household purposes has practically been abandoned.

Aneroid means liquidless. This barometer does not contain any dangerous elements, therefore it is suitable for measuring atmospheric pressure even during a hiking trip or sea voyage.

Barometer-altimeter Mingle BKT381, designed for tourists, climbers, hunters

By the way, there are also models of barometers on sale intended for hunters, tourists, and climbers. However, most often a barometer is an excellent souvenir that is placed on a table or hung on a wall in an office or home office.

Of course, in our age of high technology, barometers are also electronic. In this electronic form, they exist as part of home weather stations, which make it possible to fairly accurately predict the weather for the near future, measuring not only atmospheric pressure, but also a number of other quantities by which we judge the weather. And, of course, electronic devices are widely used in navigation.

For example, the Weems & Plath 4002 professional electronic barometer has much greater functionality than a conventional analog device. Such a barometer records readings for the last 48 hours, and you can set an audible alert for it if the pressure has gone beyond the user-selected limits. In addition to pressure, the device measures temperature and humidity, and it also has a built-in alarm clock.

Electronic barometer Weems & Plath 4002

It should be noted that digital barometers, unlike conventional analog ones, are less sensitive to shaking, which is inevitable at sea. Therefore, the owner of a yacht, boat, or other means of transportation on water will be much more pleased with a good electronic barometer, capable of giving accurate readings during any motion, than with a beautiful, but more capricious analog device, even if made of shiny metal or expensive wood.

At the same time, it is analog barometers, the appearance of which reminds us of the era of brave sailors discovering new lands, that are more suitable as a gift. However, some people like classic watches with hands, while others prefer to keep track of time using an electronic scoreboard. The same is true with barometers and weather stations.

Vitek Wireless Weather Station/Digital Photo Frame

Electronic devices fit perfectly into a modern interior, and their functionality is higher. The picture above shows a weather station that is also a photo frame. Such a gift will certainly please a person who is focused on all the most modern and high-tech.

Atmosphere pressure

So, barometers measure atmospheric pressure. What is it and what significance does it have in shaping the weather? The above-mentioned scientist Torricelli once came to the conclusion that air has weight, which means that the atmosphere, consisting of several layers of air, exerts pressure on the Earth. To measure it, he conducted an experiment with mercury placed in an empty vessel.

As a result, normal atmospheric pressure was measured, which at an air temperature of 15 ° C is considered to be a pressure of 760 mm Hg. Art. (millimeters of mercury). In this case, we are talking about optimal readings at the so-called sea level. Whereas high in the mountains the pressure is lower, because the layer of atmosphere there is smaller. When climbing mountain peaks, a person may experience altitude sickness, which is associated with difficult lung function at low atmospheric pressure and a decrease in oxygen concentration. Thus, atmospheric pressure is important for our health.

Home barometers measure pressure in the range of 700-800 mmHg. Art. at an altitude of no more than 300 m above sea level. These limits are sufficient to represent normal changes in atmospheric pressure. In general, at the epicenter of a tornado, pressure can drop down to 560 mm Hg. Art. So the approaching low pressure zone, which we are periodically promised in television forecasts, means just worsening weather conditions, rain and snowfall. These zones with low pressure are also called cyclones, and those with high pressure are called anticyclones. Originating in one part of the globe, they are able to move over vast distances and, as a result, dictate the weather in a completely different part of the globe. The approach of cyclones, which bring with them a decrease in atmospheric pressure, negatively affects the well-being of many people, especially those who suffer from cardiovascular diseases.

The barometer helps predict deterioration in health and take the necessary medications on time.

It should also be noted that atmospheric pressure is measured not only in millimeters of mercury. Barometer readings can be given in millibars, which is the unit of measurement used by sailors. A normal pressure is 1013 mbar, which corresponds to 760 mmHg. Art. And in the international SI system, familiar to us from physics lessons, pressure is usually measured in hectopascals. However, the normal pressure indicator is also 1013 hPa.

In general, if you are not going to cross the Atlantic Ocean on a sailboat alone, a thorough knowledge of the features of measuring atmospheric pressure in different conditions is of no use to you. On any barometer, in one form or another, there are marks “Rain”, “Clear”, “Cloudy”. And when the arrow approaches the sun drawn under the glass, you don’t have to worry about getting your shoes wet. And the instructions for the device must necessarily describe how to correct the operation of the barometer if its readings do not correspond to the readings of the local weather station, that is, they are not accurate enough.

Who would be interested in such a gift?

A large number of online stores offering gift items for men include barometers. Indeed, such a souvenir is unlikely to be of interest to a girl, but men have always liked various devices. Of course, barometers vary in appearance, but still we are not talking about cute floral designs or glamorous Swarovski stones on the body of the device. Wood and metal are the main materials used in the manufacture of analog barometers.

Barometer PB-14 M made of high-quality wood

Barometers are quite consistent with men's tastes and fit well into both classic and ultra-modern interior design. They perfectly coexist with the latest gadgets, without which in our time it is difficult to imagine not only the work space, but also the home space of a business person. And if a barometer, the body of which is made in the shape of a ship’s steering wheel, will look better in a room furnished with good-quality wooden furniture, then the device, placed in a strict rectangular metal case, can be safely hung on the same wall with an ultra-thin LCD TV.

Metal wall barometer Sea Power

Style

If functionally all analog barometers are practically the same from each other, then their design may be different. It is the appearance and build quality that you have to focus on when choosing this souvenir. Let's look at the different designs of barometers.

Antique

The classic round barometer, made in the old Russian style, looks solid, it can be hung either on the wall of the office or in the living room at home.

It was already mentioned above that there are also barometers on sale that you can take with you on a hike or hunting; they are compact and can easily withstand the corresponding operating conditions. Now we will talk about wall barometers in a wooden or metal case, the design of which is based on the theme of hunting.

Barometer BRIG "Hunter"

Such a souvenir is perfect not only for those who like to shoot ducks, although it is definitely made with such an aim in mind. This gift will fit well into the interior of a country house. It can be hung above the sofa in the living room, where we often find space for other souvenirs, such as an antique blade or a hunting trophy.

Barometer-steering wheel

Real men know how to overcome difficulties; they don’t care about the trials of sea travel, when huge waves wash over the sides of the ship, and the salty wind hits the face. The maritime theme has always excited the imagination of boys, and, becoming adults, they continue to see courageous, fearless people in sailors. Therefore, it is not for nothing that manufacturers often give a steering wheel design to such an instrument as a barometer, which is directly related to shipping.

Barometer-helm BRIG

The owner of this barometer can easily feel like the captain of a ship plowing the stormy waters of the Atlantic, and in general such a souvenir looks solid, it is clearly intended for a serious person who is used to being at the helm. It will look great next to the director's chair or next to a large bookcase filled with volumes of classic works, as well as in a modern bedroom.

Anchor

Many gifts have not only practical, but also symbolic meaning. The anchor barometer, along with the aforementioned steering wheel, not only exploits the popular maritime theme, but is also associated with reliability, stability, and confidence. Such a gift can emphasize your attitude towards the man for whom it is intended, as a person who can be counted on in any situation.

Sea Power anchor barometer (brass body)

Tabletop barometers

Some barometer models are wall-mounted, while others can simply be placed on a table. A desktop barometer will best fit into the interior of a personal office; it will easily find its place next to a solid stand for writing instruments. However, such a souvenir will look good on a student’s desk, next to a computer and stacks of textbooks.

Sea Power Tabletop Barometer

Determinants of cost

Basically a barometer is a small object. The diameter of the dial is usually 7-10 cm. Of course, the larger the dial, the more convenient it is to view the barometer readings, but there is a direct relationship between the size of the device and its price. Naturally, the cost of a barometer is also determined by the prestige of the brand under which it is produced and the quality of the materials from which it is made. The high measurement accuracy declared by the manufacturer, the low sensitivity of the device to operating conditions and the exclusive design also increase the price of the product.

Barometer "Rudder" Sea Power

Let's say, this brilliant, handsome barometer from the English brand Sea Power with a dial with a diameter of 15 cm, made of brass, is sold at a price approximately 6 times higher than the barometer of the Russian company BRIG PB-17 Gold with a dial with a diameter of 12 cm, made of golden metal colors. The latter also has a built-in hygrometer (humidity meter) and thermometer.

Barometer BRIG PB-17 Gold

Some useful tips for handling barometers

Barometers cannot be transported on airplanes. Therefore, if you decide to bring a beautiful barometer from a trip to an exotic country, keep in mind that the device is unlikely to survive a flight across the ocean, especially if it travels in the cargo hold along with your suitcase. The thing is that at high altitudes, the pressure goes beyond the limits in which the barometer makes measurements, and this can damage its mechanism. Sudden changes in altitude, such as when driving a car quickly down a mountain, can also negatively affect the performance of the barometer. So try to avoid such overloading of the device.

The instructions for the barometer should indicate the temperature range at which it can operate. Usually we are talking about thermometer readings within the range of -10 °C...+50 °C. And if in our climate one should not expect such heat as in the Sahara, then frosts of -25 ° C are commonplace. Therefore, you should not take the barometer outside when you yourself are forced to wrap yourself tightly in a fur coat. It won't do him any good. It is also not recommended to use the barometer in rooms with high humidity.

conclusions

It often happens that a gift or souvenir looks beautiful, carries a certain meaning, both we and the person for whom it is intended like it, but it does not bring any benefit other than aesthetic ones. On the one hand, a barometer is a meteorological instrument, its purpose is obvious. On the other hand, it is perfect as a stylish gift that easily fits into almost any interior, looks solid and even expensive. The man to whom you give a barometer will probably like it, because such a gift is not only beautiful, but also an interesting thing that has practical applications. After all, it’s always nice to have an accurate weather forecast, while others are arguing whether it’s worth taking an umbrella with you today.