Development and application of multi-component dynamic gas distribution instrument based on mass flow controller

Sulfur hexafluoride (SF
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) equipment plays an important role in the power system. SF
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gas in the equipment not only plays the role of insulation and arc suppression, but also is the information carrier of the equipment status. The moisture, impurities and leakage in SF
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gas is an important index and basis to evaluate the state of SF
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electrical equipment. Therefore, how to make good use of all kinds of testers to analyze and monitor SF
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gas is the most important thing. At present, in order to solve the problems of high standard gas cost, short period of validity and long ordering cycle, which are needed in the calibration of these instruments, we are indicated to research an eight-component dynamic gas distribution device based on mass flow controller (MFC) in this paper. Based on MFC theory, through relevant hardware and software design, the device obtains a gas distribution instrument for continuously preparing and supplying eight-component mixed standard gas with continuously adjustable concentration, so as to meet the calibration needs of SF
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component analyzer, purity meter and leak detector. Compared with the four groups, the eight-group gas distribution instrument just needs to connect the dynamic gas distribution device and the gas pipeline of the tested instrument when verifying the SF
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decomposition product instrument, and simple parameter setting in the computer management system. The computer automatically controls the single-component or multi-component mixed standard gas needed for the configuration and verification of the dynamic gas distribution system through serial communication, and it do not need to change the gas path. At the same time, the device can check the multiple instruments by simple operation.