Barometer - what is it? Apparatus for measuring atmospheric pressure

Barometer, what is it? This device is designed to account for fluctuations in atmospheric pressure. The surface layer of our planet has a thickness of tens of kilometers. The concentration of mixed gases in it differs in a small mass, however, in such significant volumes, a significant load on the surface takes place. In fact, a person rarely feels it, since it has the adaptability to the effect of this factor. Nevertheless, this value is quite realistic to measure.

The principle of operation of the simplest devices

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

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

Aneroid and mercury device

An aneroid-barometer, what is it? In principle, the work of this device takes into account oscillations through a round metal case with wavy walls, from which air is pumped out.

Elastic sidewalls of the box with bending pressure, bend, and with a decrease - stick out. A special mechanism for working chambers is associated with the arrow. It shows the value of atmospheric pressure on a scale graduated in millimeters of a mercury column.

The instrument for measuring atmospheric pressure is a U-shaped curved glass flask with a mercury filler. Indications are determined by the difference in content in the enlarged and small section of the bulb.

With the help of barographs, variations in blood pressure are recorded on a tape in an active drum-type unit. The measured values are recorded in millimeters (mm Hg) or millibars (mbar).

Barograph

Then the barograph is presented. The question - the barometer, what it is in this configuration, you can answer - it's a recorder-recorder for constant fixation of 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 reading is increased, the boxes are squeezed, the pen with the pen goes up, and if the pressure of the chamber decreases, the control spring becomes wider, and the recorder guides the bottom line. Fixed pressure readings are subtracted on a special graded paper tape, which is placed on a rotating drum.

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

Features of use

The barometer readings are recorded taking into account changes in climatic conditions in different regions, since air pressure is a variable quantity, which is known from school lessons of natural history.

With a good, warm and windless weather, the barometer is wall-mounted or tabletop showing high values. Accordingly, with the reduction of data in the near future, cooling or precipitation is expected.

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

Height adjusting device

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

Undoubtedly, the results of the first, not quite perfect instruments, significantly varied from the weather factors, because negative weather conditions were accompanied by a drop in pressure, respectively, the instrument readings showed data that was objectively larger than the real mark. To correct the correct reading, the outgoing parameters must be adjusted. The principle of operation of modern altimeters is different - they do not use atmospheric pressure to measure altitude.

How to use?

A clock 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 is taken in millimeters of mercury.

At the values of 750-760 mm Hg. Art. In the future, a remarkable fine day is expected, which will not prevent a walk, a trip to nature, a summer residence. With a drop in the barometer indicator below 750, there is a possibility of further fall, which means expecting inclement weather, sudden cooling and abundant precipitation.

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

Modern specimens

Now barometric cups or siphon types are most often used. In stationary devices that are equipped with a compensated scale, the atmospheric pressure is calculated directly from the position of mercury in the glass container.

In specimens for expeditions, before starting observations, the level of mercury in the bowl at the zero mark is first corrected using a regulating screw. In siphon-cup devices, the value of AD is measured by the difference in height of the column in a long and open area. Such a device counts the readings to within five hundredths. To determine the tenths of the column, a mobile metal pattern is used.

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

Features

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

• Impenetrability for water, up to 50-100 meters.
• Stability to impacts and mechanical influences, which is important for fishermen, hunters and lovers of extreme recreation.
• The barometer allows you to predict the changes in atmospheric pressure and weather in general.
• In addition, the clock 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 this?" You can definitely answer - the device is especially important for travelers, fishermen, hunters and seafarers. In addition, this piece in household use allows you to accurately predict weather fluctuations, which is important for people with diseases of the cardiovascular and nervous system.