What Is a Barograph?
The barometer is based on the experimental principle of Evangelista Torricelli (1608 ~ 1647), an instrument for measuring atmospheric pressure.
- Chinese name
- Barometer
- Foreign name
- barometer
- Species
- Mercury barometer and aneroid barometer
- By principle
- Torricelli's experimental principle
- Use
- Forecast weather changes, altimetry
- working principle
- Mercury pressure
- The barometer is based on the experimental principle of Evangelista Torricelli (1608 ~ 1647), an instrument for measuring atmospheric pressure.
Barometer definition
Barometer name
- Chinese name: barometer
- English name: barometer
Barometer Overview
- Barometer
Barometer type
- The types of barometers include mercury barometers and liquid barometers.
Use of barometer
- It can predict the change of weather. When the air pressure is high, it will be sunny; when the air pressure is low, there will be wind and rain.
- Measurable height. For every 12 meters, the mercury column decreases by about 1 mm, so the height of the mountain and the height of the aircraft in the air can be measured.
How the barometer works
Barometer mercury pressure
- A device for measuring atmospheric pressure using a Torrix tube. The mercury tank at the bottom of the glass tube is replaced by a skin bag with an ivory needle that can be adjusted to indicate the mercury surface. It is called a "Futing mercury barometer". A metal sheath is placed on the outside of the glass tube. A scale is engraved on the tube to measure the height of the mercury column. Install another ivory needle on the top of the mercury tank. The needle tip is exactly at the zero point of the scale outside the tube, and a leather bag is used as the bottom of the mercury tank. When in use, turn the screw under the bag lightly so that the mercury surface in the groove just contacts the ivory needle tip (that is, it is on a horizontal line with the zero point of the scale), and then read the height of the mercury column from the scale on the tube. This altitude indicator is the local atmospheric pressure at that time. In addition, there are barometers for observation stations that do not need to be adjusted for ivory needles, barometers that can measure low-pressure mountains, and marine barometers that are not sensitive to the ship's shaking.
- The height of the mercury column supported by different atmospheric pressures is different. According to P = p (mercury density) hg, the calculated pressure is equal to the atmospheric pressure. Of course, this calculation is made by counting the barometric pressure on the barometer. Scale, you can know the size of the air pressure!
Barometer
- Aneroid barometer is a kind of barometer, the most common is a metal box barometer.
- Its main part is a vacuum metal box with a corrugated surface. In order not to crush the metal box by the atmospheric pressure, it is pulled outwards with an elastic steel sheet. When the atmospheric pressure increases, the lid is recessed a little; when the atmospheric pressure decreases, the elastic steel sheet pulls up the lid. The change of the box cover is transmitted to the pointer through the transmission mechanism, so that the pointer is deflected. From the reading on the dial below the pointer, you can know the value of atmospheric pressure at that time.
- It is easy to use and portable, but the measurement results are not accurate enough. If the dial on the aneroid barometer is not the value of atmospheric pressure, but the altitude, it will become an altimeter for aviation and mountaineering.