Working principles of SF6 gas density table
1. When the density meter is not installed, if the ambient temperature is 20 ℃, the pointer 2 points to 0MP, but if the ambient temperature is not 20 ℃, because the double-layer metal belt 3 is in accordance with the ambient temperature and 20 ℃ difference to compensate So that when the ambient temperature is higher than 20 ° C, the double-layer metal strip 3 is elongated and its lower end is displaced in the direction of 5, causing the gear mechanism and the pointer 2 to move in the direction in which the density or pressure indication value decreases, The reading of the pointer 2 is greater than 0MP; otherwise, when the ambient temperature is below 20 ° C, the gear mechanism and the pointer 2 will move in the direction of increasing the density or pressure indication value.
2. When the SF6 gas is charged to the circuit breaker, the end of the elastic metal pipe 1 is displaced in the direction of 4 as the gas pressure is gradually increased, and the double-layer metal strip 3 is always compensated at 20 ° C As the displacement occurs toward the direction of 4, the gear mechanism and the pointer 2 are moved in the direction in which the density or pressure indication value increases, and the indication value becomes larger. The indication of a density gauge or pressure gauge is not only related to pressure, but also to temperature. In the process of filling the circuit breaker with SF6 gas, due to the sudden expansion and contraction of the SF6 density relay, the temperature is generally lower than the ambient temperature below 0 ℃, the double-layer metal belt 3 is always compensated at 20 ℃, and can not SF6 gas actual temperature and The temperature difference between the ambient temperature is compensated. Therefore, in this case, the indication value of the density meter can not represent the density or pressure value at the actual temperature of the sf6 gas density monitor, nor can it represent the density or pressure value at ambient temperature Can not represent a density or pressure value at 20 ° C.
2. When the SF6 gas is charged to the circuit breaker, the end of the elastic metal pipe 1 is displaced in the direction of 4 as the gas pressure is gradually increased, and the double-layer metal strip 3 is always compensated at 20 ° C As the displacement occurs toward the direction of 4, the gear mechanism and the pointer 2 are moved in the direction in which the density or pressure indication value increases, and the indication value becomes larger. The indication of a density gauge or pressure gauge is not only related to pressure, but also to temperature. In the process of filling the circuit breaker with SF6 gas, due to the sudden expansion and contraction of the SF6 density relay, the temperature is generally lower than the ambient temperature below 0 ℃, the double-layer metal belt 3 is always compensated at 20 ℃, and can not SF6 gas actual temperature and The temperature difference between the ambient temperature is compensated. Therefore, in this case, the indication value of the density meter can not represent the density or pressure value at the actual temperature of the sf6 gas density monitor, nor can it represent the density or pressure value at ambient temperature Can not represent a density or pressure value at 20 ° C.
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