A device for accounting for fluctuations in atmospheric pressure. The above-ground layer of our planet has a thickness of tens of kilometers. The concentration of mixed gases in it is distinguished by a small mass, but in such significant volumes it exerts a significant load on the surface. In fact, a person rarely feels it, as he has an adaptability to the effects of this factor. However, this value is quite realistic to measure.

The principle of operation of the simplest devices

The simplest device for measuring atmospheric pressure (BP) is a simple device consisting of a thin-walled glass tube and mercury filler. One of the standard sizes of such a device: a tube 1 millimeter thick and a hundred centimeters long.

If you turn the container with the closed end up and the open part down, then a certain amount of mercury will be removed, and a certain part will remain inside. The liquid metal content will decrease until the internal and external pressure stabilizes.

Aneroid and mercury device

Aneroid barometer, what is it? The principle of operation of this device takes into account vibrations through a round metal case with wavy walls, from which air is pumped out.

The elastic sidewalls of the box bend with an increase in pressure, and bulge out with a decrease. By a special mechanism, the working chambers are connected with the arrow. It indicates the value of atmospheric pressure on a scale graduated in millimeters of mercury.

The instrument for measuring atmospheric pressure is a U-shaped bent glass flask filled with mercury. Indications are determined by the difference between the contents in the enlarged and small segment of the flask.

With the help of barographs, BP variations are recorded on a tape located in an operating drum-type unit. Measured values ​​are recorded in millimeters (mmHg) or millibars (mbar).

Barograph

The following is a bargraph. To the question - a barometer, what it is in this configuration, you can answer - this is a recorder unit for constantly fixing atmospheric pressure. Its action is based on fluctuations in blood pressure. As a result, the deformation is transferred by the system to the device. When the readings increase, the boxes are compressed, the lever with the pen goes up, and in the case of a decrease in pressure, the chambers become wider under the action of the control spring, and the recorder draws the bottom line. Fixed pressure readings are subtracted on a special graduated paper tape, which is placed on a rotating drum.

To eliminate temperature fluctuations that affect the accuracy of the readings, bimetal capacitors are mounted in the devices. Devices are installed away from heating devices and must be protected from direct exposure to sunlight. The winding mechanism is designed for a day or a weekly regime.

Features of use

Barometer readings are fixed taking into account changes in climatic conditions in different regions, since air pressure is a variable value, which has been known since school lessons in natural history.

In good, warm and calm weather, a wall or table barometer shows high values. Accordingly, with a decrease in data, cooling or precipitation is expected in the near future.

A device located inside the house works exactly the same as in a space not limited by fences, walls and fences. The height of the building slightly modifies the readings of the device, since the pressure will be lower on the 9th floor and higher than at lower levels of the same building.

Height Adjustment

The higher the rise, the lower the pressure of the atmospheric column. The revealed pattern is used in aircraft instruments that determine the flight altitude. Such devices are called altimeters.

Of course, the results of the first, not quite perfect devices, varied significantly from weather factors, because negative weather conditions were accompanied by a pressure drop, respectively, the readings of the device highlighted data that were objectively greater than the real mark. To take the correct readings, an adjustment of the outgoing parameters is required. The principle of operation of modern altimeters is different - they do not use atmospheric pressure to measure altitude.

How to use?

A watch with a barometer and other types of devices is a pointer device with a round or oval scale, on which there are divisions. The measurement value is taken in millimeters of mercury.

At values ​​of 750-760 mm Hg. Art. in the future, a wonderful fine day is expected, which will not interfere with a walk, a trip to nature, a summer house. If the barometer pointer drops below 750, there is a possibility of a further fall, which means that we should expect inclement weather, a sudden cold snap and heavy rainfall.

Monitoring blood pressure is vital for those who suffer from high blood pressure. During periods of critical change in this indicator, such people are subject to deterioration in their health. Information about weather changes is essential for them because of the timely taking of the medicine, maintaining their working capacity and health.

Modern specimens

Now the most commonly used barometers are cup-type or siphon types. In stationary devices that are equipped with a compensated scale, the atmospheric pressure is calculated directly from the position of the mercury in the glass container.

In specimens for expeditions, before the start of observations, the mercury level in the cup is preliminarily corrected at the zero mark using the adjusting screw. In siphon-cup devices, the value of blood pressure is measured by the difference in the heights of the column in a long and open section. Such a device counts readings with an accuracy of five hundredths. To determine the tenths of the column, a movable metal template is used.

The obtained numerical results of atmospheric pressure are given according to a special table to zero degrees Celsius. Temperature adjustments to readings can be quite significant. Regardless of the types of barometers, they are installed away from heat sources (stoves, heaters, direct sunlight), as well as away from door and window openings.

Peculiarities

The considered device can be used in a convenient and compact design. For example, a watch with a barometer has the following functionality:

• Impervious to water, up to 50-100 meters.
• Resistance to impacts and mechanical stress, which is important for fishermen, hunters and lovers of extreme recreation.
• The barometer allows you to predict changes in atmospheric pressure and weather in general.
• In addition, the watch can be equipped with a thermometer, backlight, compass and even a navigator, which makes it much easier to stay in an unfamiliar area.

To the question "Barometer, what is it?" You can definitely answer - the device is especially important for travelers, fishermen, hunters and sailors. In addition, this thing in domestic use allows you to fairly accurately predict weather fluctuations, which is important for people with diseases of the cardiovascular and nervous systems.

home comfort

Barometer - what is it? Atmospheric pressure measuring instrument

Barometer, what is it? This is a device for taking into account fluctuations in atmospheric pressure. The above-ground layer of our planet has a thickness of tens of kilometers. The concentration of mixed gases in it is distinguished by a small mass, but in such significant volumes it exerts a significant load on the surface. In fact, a person rarely feels it, as he has an adaptability to the effects of this factor. However, this value is quite realistic to measure.

The principle of operation of the simplest devices

The simplest device for measuring atmospheric pressure (BP) is a simple device consisting of a thin-walled glass tube and mercury filler. One of the standard sizes of such a device: a tube 1 millimeter thick and a hundred centimeters long.

If you turn the container with the closed end up and the open part down, then a certain amount of mercury will be removed, and a certain part will remain inside. The liquid metal content will decrease until the internal and external pressure stabilizes.

Aneroid and mercury device

Aneroid barometer, what is it? The principle of operation of this device takes into account vibrations through a round metal case with wavy walls, from which air is pumped out.

The elastic sidewalls of the box bend with an increase in pressure, and bulge out with a decrease. By a special mechanism, the working chambers are connected with the arrow. It indicates the value of atmospheric pressure on a scale graduated in millimeters of mercury.

The instrument for measuring atmospheric pressure is a U-shaped bent glass flask filled with mercury. Indications are determined by the difference between the contents in the enlarged and small segment of the flask.

With the help of barographs, BP variations are recorded on a tape located in an operating drum-type unit. Measured values ​​are recorded in millimeters (mmHg) or millibars (mbar).

Barograph

The following is a bargraph. To the question - a barometer, what it is in this configuration, you can answer - this is a recorder unit for constantly fixing atmospheric pressure. Its action is based on fluctuations in blood pressure. As a result, the deformation is transferred by the system to the device. When the readings increase, the boxes are compressed, the lever with the pen goes up, and in the case of a decrease in pressure, the chambers become wider under the action of the control spring, and the recorder draws the bottom line. Fixed pressure readings are subtracted on a special graduated paper tape, which is placed on a rotating drum.

To eliminate temperature fluctuations that affect the accuracy of the readings, bimetal capacitors are mounted in the devices. Devices are installed away from heating devices and must be protected from direct exposure to sunlight. The winding mechanism is designed for a day or a weekly regime.

Features of use

Barometer readings are fixed taking into account changes in climatic conditions in different regions, since air pressure is a variable value, which has been known since school lessons in natural history.

In good, warm and calm weather, a wall or table barometer shows high values. Accordingly, with a decrease in data, cooling or precipitation is expected in the near future.

A device located inside the house works exactly the same as in a space not limited by fences, walls and fences. The height of the building slightly modifies the readings of the device, since the pressure will be lower on the 9th floor and higher than at lower levels of the same building.

Height Adjustment

The higher the rise, the lower the pressure of the atmospheric column. The revealed pattern is used in aircraft instruments that determine the flight altitude. Such devices are called altimeters.

Of course, the results of the first, not quite perfect devices, varied significantly from weather factors, because negative weather conditions were accompanied by a pressure drop, respectively, the readings of the device highlighted data that were objectively greater than the real mark. To take the correct readings, an adjustment of the outgoing parameters is required. The principle of operation of modern altimeters is different - they do not use atmospheric pressure to measure altitude.

How to use?

A watch with a barometer and other types of devices is a pointer device with a round or oval scale, on which there are divisions. The measurement value is taken in millimeters of mercury.

At values ​​of 750-760 mm Hg. Art. in the future, a wonderful fine day is expected, which will not interfere with a walk, a trip to nature, a summer house. If the barometer pointer drops below 750, there is a possibility of a further fall, which means that we should expect inclement weather, a sudden cold snap and heavy rainfall.

Monitoring blood pressure is vital for those who suffer from high blood pressure. During periods of critical change in this indicator, such people are subject to deterioration in their health. Information about weather changes is essential for them because of the timely taking of the medicine, maintaining their working capacity and health.

Modern specimens

Now the most commonly used barometers are cup-type or siphon types. In stationary devices that are equipped with a compensated scale, the atmospheric pressure is calculated directly from the position of the mercury in the glass container.

In specimens for expeditions, before the start of observations, the mercury level in the cup is preliminarily corrected at the zero mark using the adjusting screw. In siphon-cup devices, the value of blood pressure is measured by the difference in the heights of the column in a long and open section. Such a device counts readings with an accuracy of five hundredths. To determine the tenths of the column, a movable metal template is used.

The obtained numerical results of atmospheric pressure are given according to a special table to zero degrees Celsius. Temperature adjustments to readings can be quite significant. Regardless of the types of barometers, they are installed away from heat sources (stoves, heaters, direct sunlight), as well as away from door and window openings.

Peculiarities

The considered device can be used in a convenient and compact design. For example, a watch with a barometer has the following functionality:

• Impervious to water, up to 50-100 meters.
• Resistance to impacts and mechanical stress, which is important for fishermen, hunters and lovers of extreme recreation.
• The barometer allows you to predict changes in atmospheric pressure and weather in general.
• In addition, the watch can be equipped with a thermometer, backlight, compass and even a navigator, which makes it much easier to stay in an unfamiliar area.

To the question "Barometer, what is it?" You can definitely answer - the device is especially important for travelers, fishermen, hunters and sailors. In addition, this thing in domestic use allows you to fairly accurately predict weather fluctuations, which is important for people with diseases of the cardiovascular and nervous systems.

What is atmospheric pressure? What is the name of the instrument for measuring atmospheric pressure? Tell us about its structure. Name normal atmospheric pressure. How and why does pressure change when ascending mountains and descending into depressions? Why is air pressure on the earth's surface constantly changing?

1) =20 mm. rt. Art. 2) 20 × 10.5 = 210 meters Answer: 210 meters

1) =45 mmHg Art. 2) 45 × 10.5 \u003d 427.5 m height Answer: 427.5 m.

Long before science gave a precise definition of the concept of "wind" and found an explanation for its occurrence, man learned to use the power of the wind. Sailing ships sailed on the sea. The wind, filling the sails, made it possible to cross the oceans and make geographical discoveries. For example, the great traveler Christopher Columbus crossed the Atlantic Ocean on sailing caravels and discovered a new continent - America.

Velocity The distance that air travels per unit of time. Expressed in m / s Instrument - anemometer Force The pressure exerted by air on an area of ​​​​1 square. m, located perpendicular to the movement of air. Expressed in points Direction The direction is determined by the side of the horizon from which the wind is blowing. Wind direction is expressed in points. The main points are north, south, east and west. The device is a wind vane.

The strongest winds on Earth, 104 m/s, were recorded on Mount Washington (Appalachian mountain range) (USA). The windiest place on Earth is Cape Denison (Antarctica), 300 days a year the winds reach 89 m/s.

Wind strength (points) Wind speed m/s (km/h) Designation Wind action 0.0.0-0.5 (0) CalmSmoke rises vertically. 1.0.6-1.7 (4) Quiet Light air movement 2.1.8-3.3 (9) Light Leaves rustle, the face feels the wind 3.3.4-5.4 (16) Weak Leaves and thin branches sway 4.5.5-7, 9 Moderate Tree tops bend, dust rises 5.8.0-10.7 Fresh Branches and thin trunks sway 6.10.8-13.8 Strong Thick branches sway, wires hum 7.13.9-17.1 Strong Trunks sway, it is difficult to go against the wind 8.17.2-20.7 Very strong Break small branches, very difficult to walk 9.20.8-24.4 Storm Thick branches break, buildings damaged 10.24.5-28.4 Strong storm Trees break, large damage 11.28.5-32.6 Violent storm Large destruction 12.Over 32.7 Hurricane Devastating destruction

Name of the windDistribution areas Direction Trade windsTropicsN.-E.,S.-E. Winds zap. transferModerate latitudesZ., S.-Z. MonsoonsEast coast of Eurasia and North. America In summer - from the ocean to the mainland, in winter - from the mainland to the ocean. Stock windsAntarcticaFrom the center of the mainland to the periphery BreezeSea coastsDuring the day - from the sea to land, at night - from land to the sea FenMountain systems. Especially the Alps, the Pamirs, the Caucasus From the mountains to the valleys

What is wind? What are the reasons for the formation of wind What is the windiest place on Earth. What winds do you know? How do they blow? What are the instruments that measure the strength, speed and direction of the wind? What is the importance of wind in nature and human life? Paragraph 39 p Plot the wind rose for February according to your observations.

Instruments for measuring atmospheric pressure are called barometers. Pressure is determined by the weight of a column of atmospheric air pressing on a given area of ​​the Earth's surface. Because the overlying air is thinner at higher altitudes, such as the top of a mountain, atmospheric pressure decreases with height. Atmospheric pressure also changes with the movement of air masses that form cold and warm atmospheric fronts. Therefore, it is possible to predict the weather from barometer readings.

There are two main types of barometers currently in use: mercury and aneroid. The mercury barometer, invented in 1643 by the Italian scientist Evangelista Torricelli, uses a mercury-filled glass tube that rises and falls as atmospheric pressure increases or decreases. An aneroid barometer, similar to the one shown on the right, was invented in 1843 by the French scientist Lucien Vidie. The main part of the aneroid is a small corrugated metal membrane box, from which the air is almost completely evacuated (diagram below). When atmospheric pressure changes, the membrane box expands or contracts. The sensitive mechanism converts the movement of the membranes into a circular movement of the arrow showing the pressure value on the scale of the device.

Internal arrangement of an aneroid barometer

A series of levers within the barometer amplify small movements as the membrane box expands and contracts. Most aneroid barometers are less than 20 cm across.

(Figure at the top of the article)

The thin stylus of a barograph continuously records atmospheric pressure on a rotating drum.

A change in atmospheric pressure causes the mercury in the tubes to rise or fall. The height of the mercury columns depends only on atmospheric pressure, the diameter and shape of the tubes do not matter. At sea level, the mercury column rises by 760 millimeters.

Two simple metal hemispheres demonstrate the existence of atmospheric pressure. After all the air is pumped out of the hemispheres and a vacuum has formed in them, atmospheric pressure makes it impossible to separate them.

One of the most accurate instruments used to measure atmospheric pressure at all meteorological stations is the so-called station cup barometer. It is a glass tube about 80 cm long, with a cross section of 1 cm2. Its upper end is sealed, and the lower open end is lowered into a cup with mercury. The tube is filled with mercury; in the unfilled part of the tube - airless (more precisely, extremely rarefied) space.

To protect the tube from mechanical damage, it is enclosed in a metal frame. Schematic diagram of the device of a marine cup barometer: two longitudinal slots are made on both sides, one opposite the other, necessary to determine the height of the mercury column in the tube. On the left side of the front slot, a scale is applied: in old barometers, in millimeters, in new ones, in millibars. To read the pressure on the scale, a movable ring with a vernier is used. Moving the vernier along the slot is done with the help of a screw located on the right side of the frame. Before counting, the lower cut of the vernier is brought to the upper point of the visible meniscus of mercury, and then the pressure is read with tenths: integers are counted from the lower cut of the vernier, and tenths - from divisions of the vernier (from 0 to 9). Tenths (mm or mb) are judged by the division of the vernier, which exactly coincides with any division on the scale. To allow air to enter the cup with mercury, a small hole was made in it, loosely closed with a screw cap.

The station cup barometer is installed in the meteorological station in a special cabinet in a vertical position.

The marine mercury barometer, as its name suggests, is designed to measure atmospheric pressure on ships. In principle, it is arranged in the same way as the station cup barometer, and differs from it in smaller dimensions and a narrower barometric tube with extensions at its ends. The narrowing of the middle part of the tube to the thickness of the capillary is done to reduce the fluctuation of mercury in the tube during the motion of the vessel and to prevent the penetration of air bubbles into the mercury. The mercury cup is made narrower than in the station barometer. It also largely eliminates the effect of the ship's motion on the condition and readings of the barometer.

The marine barometer is suspended on a ship in an enclosed space on a gimbals.

The aneroid barometer, or simply aneroid, is a simple and easy-to-use instrument widely used to measure atmospheric pressure on ships.

The operating principle of the aneroid is based on measuring the degree of deformation of the walls of a hollow flat metal pressure box under atmospheric pressure.

The aneroid box, being the receiving part of the device, is very sensitive to changes in atmospheric pressure. The sensitivity of the pressure box is achieved by the fact that the air in it is very strongly discharged. When the pressure increases, the box contracts, and when it decreases, it expands. To avoid complete deformation of the box, which is possible under the action of atmospheric pressure, an arcuate spring is attached to it, which, by stretching the box, balances the atmospheric pressure acting on it.

Compression and tension of the box are transmitted to the barometer pointer through a system of rods and levers. The aneroid scale is graduated either in millimeters or in millimeters of mercury stobe. The aneroid was calibrated under the condition that the pressure box temperature at all pressures is 0°. Therefore, in order to determine the correction for the reading of the aneroid, which depends on the temperature, the temperature of the device itself is determined each time when reading the pressure. The latter is determined by a thermometer mounted in an arcuate slot on the front surface of the aneroid.

The aneroid mechanism is enclosed in a round metal or plastic box, glazed on the front side. The device is always stored in a special case with an opening lid.

The aneroid barometer, in comparison with the mercury barometer, is a less accurate instrument, but it is almost insensitive to the motion of the ship. This makes it more convenient to use and store on board. The main disadvantage of aneroids is the gradual decrease in their sensitivity and accuracy of indication due to the residual deformation of the anerondia box and spring that occurs over time. To eliminate these shortcomings, aneroids must be periodically checked in special institutions of the Hydrometeorological Service - in the verification bureau. Verification of aneroids should be done every six months.

The barograph is intended for continuous recording of changes in atmospheric pressure. Its device is similar to that of a thermograph. It also consists of two main parts: perceiving and writing. Several (5-10) anerontal boxes, interconnected by metal spacers, serve as a pressure receiver. In order to avoid complete deformation of the boxes, which is possible under the influence of atmospheric pressure, a spring-type spring is built into each of them.

Partial total deformation in the form of small vertical displacements of the entire series of pressure boxes, arising under the influence of changing atmospheric pressure, is transmitted through a system of levers to an arrow, at the end of which a feather is mounted.

The recording of pressure in the form of a curve takes place on a drum that slowly rotates with the help of a clockwork. A paper tape is put on the drum, demarcated by horizontal lines (pressure in mb) and vertical arcs (time in hours and minutes.

Depending on the time of a full revolution of the drum, the baroriffs are "daily" and "weekly".

Using a barograph, one can determine not only the specific value of atmospheric pressure at any time, but also the magnitude and nature of its change over any time interval.

Since the change in atmospheric pressure is very closely related to the current and upcoming weather, in order to predict it in sailing conditions, it is important to know not so much the absolute value of pressure as the magnitude and nature of its change over the past few hours.

The barograph on the ship is installed indoors from springy braces or attached to a special shelf or to a table.