SF6 density monitors monitor the leakage by measuring the pressure of the SF6 gas. It is a special pressure gauge with temperature compensation. There are two kinds of that in the market ,relative pressure type monitor and absolute pressure type monitor.
SF6 density monitors relative pressure type is based on the standard atmospheric pressure,It is not sealed, the inside of the product is connected to the atmosphere. However, the use of such a monitor in high altitude areas may cause an indication error. According to the working principle of the pressure gauge, display value = SF6 gas pressure - P Atmospheric pressure, during production and setting, the atmospheric pressure is set according to the standard atmospheric pressure, but the air pressure in the high altitude area is reduced, the display value will become larger, that means the display value in the high altitude area will be larger under the same filling pressure. This will affect its alarm and blocking. For this situation, our manometers are all absolute pressure type density monitor . The so-called absolute pressure refers to a sealed monitor. The starting point is from 1 bar,you could see that from the dial of our manometer ,and the monitor is internally sealed by A standard atmospheric pressure, not connected to the outside air, display pressure = SF6 gas pressure - P atmospheric pressure, so the internal pressure of the monitor and the production setting pressure are equal, the display value will not change due to altitude changes, but if not filling with SF6 gas, the display value will become smaller due to the increase of altitude, and display value will become larger when the altitude decrease .After filling SF6 gas ,SF6 density monitors will work proper .
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