In ancient times, people determined the coming weather by signs. But such forecasting methods were very unreliable. Only over time, a person realized that it was possible to find out about the onset of bad weather or the establishment of clear weather by changing the atmospheric pressure. If the pressure drops, precipitation is expected, and when it rises, it will be clear. It is for measuring pressure that the barometer is intended.
What are the barometers
There are two main types of barometers: mercury and liquid-free, which are also called aneroids. The device, which used mercury, was invented and designed by the Italian Torricelli in the middle of the 17th century. The principle of operation of such a barometer is based on a change in the height of the mercury column located inside the device.
The mercury-type barometer includes a glass tube filled with mercury. The tube is turned upside down and is positioned over a small reservoir containing mercury. When the pressure increases, the high-density mercury is forced out of the container by gravity and begins to rise up the tube. When atmospheric pressure drops, mercury slowly descends.
The pressure level is reflected on a special scale.
The aneroid barometer uses a flexible membrane made of metal instead of mercury. A vacuum is created inside this membrane. The working element of the aneroid is connected by means of levers to a spring, to which, in turn, an indicator arrow is attached, mounted on top of a scale with divisions. In the same place, on the scale, you can read the estimated weather forecast.
Advantages and disadvantages of barometers
The advantage of a mercury device is its high accuracy of readings. The disadvantage is obvious - mercury is very dangerous for the human body, especially its vapor. For this reason, the use of mercury barometers in everyday life was abandoned; but they are still used at weather stations. These devices require careful attention to themselves.
But the non-liquid aneroid barometer does not contain components hazardous to health. Such devices can be used in everyday life, in hiking and sea travel. Household barometers do not require high measurement accuracy at all. The main thing is that the device regularly shows the approach of a storm or the establishment of clear sunny weather.
On the market you can find barometers, which are designed for hunters, fishermen, climbers, and hikers. Electronic barometers are widely used in navigation.
Some modern models of electronic barometers are essentially miniature and multifunctional weather stations. They measure not only pressure, but also air humidity. The smart device records environmental parameters for the last two days. Additionally, the device is sometimes equipped with an alarm clock and other useful functions in everyday life.
