Working principle of mercury atmospheric pressure: a device for measuring atmospheric pressure by using Torricelli tube. The mercury tank at the bottom of the glass tube is replaced by a leather bag with an ivory needle, which can be adjusted to indicate the level of mercury. This is the so-called "Fuding mercury barometer". A metal sheath is added outside the glass tube, and the sheath is engraved with scales for measuring the height of mercury column. An ivory needle is installed at the top of the mercury tank, the tip of which is just 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, gently turn the screw under the leather bag to make the mercury level in the tank just contact with 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 through the scale on the tube. This height index is the local atmospheric pressure at that time. In addition, there are observation station barometers that do not need to adjust ivory needles, barometers that measure low-pressure mountains, and nautical barometers that are insensitive to ship rolling.
Working principle of empty box barometer: empty box barometer is a kind of barometer, and the most common one is metal box barometer. Its main part is a vacuum metal box with ripples on its surface. In order to prevent the metal box from being crushed by atmospheric pressure, the elastic steel sheet is pulled outward. With the increase of atmospheric pressure, the box cover is sunken; When the atmospheric pressure drops, the elastic steel sheet will pull the cover up a little. The change of the box cover is transmitted to the pointer through the transmission mechanism, which makes the pointer deflect. From the reading on the dial below the pointer, you can know the value of atmospheric pressure at that time.
Beijing Million Electronic Science and Technology Center is a large-scale instrument manufacturer and seller. Its business fields mainly include: gas detectors, metal detectors, environmental protection equipment, medical care, laboratory instruments, chemical instruments and equipment, agricultural instruments, electromechanical equipment, fire safety equipment, power communication equipment, etc., covering almost all industries. The company's products HB403-YB-2 1 barometer take imported precision pressure sensor as the core, and have built-in circuits such as transmission, drift compensation and temperature compensation. It is widely used in meteorology, military, aviation, navigation, agriculture, surveying, geology, industrial and mining enterprises, scientific research and other fields with the advantages of accurate measurement, wide range of pressure measurement and simple use and maintenance, and has become a conventional instrument for measuring atmospheric pressure. ?