In core power scenarios such as high-voltage switchgear and GIS composite appliances, SF6 gas serves as an insulating medium, and its leakage will directly threaten the safety of equipment operation and the health of personnel. The SF6 gas online monitoring device becomes a key defense line for preventing leakage accidents by real-time monitoring of gas concentration, pressure, micro water and other parameters. The installation quality directly affects the accuracy of monitoring data and system reliability, and strict control is required throughout the entire process from location selection, equipment fixation, pipeline laying to debugging and calibration.

　　1、 Core installation location: Accurately capturing leakage sources

According to the gas density characteristics, SF6 leakage will deposit in low-lying areas of the equipment, so the detection probe needs to be installed 0.3-1.0 meters below the critical leakage point. Specifically, it includes:

1. Sealing parts of high-voltage equipment: such as flange joints, inflation ports, and maintenance ports of circuit breakers and isolating switches;

2. Gas pipeline system: connection parts such as valves, pressure gauges, and joints;

3. GIS equipment area: Set up independent detection points in each gas chamber, or add probes at the bottom, corners, and other areas where gas is prone to accumulate.

　　2、 Equipment fixation and pipeline laying: equal emphasis on stability and anti-interference

1. Host installation: It is wall mounted and fixed at the entrance of the distribution equipment room, with a height level with the human eye, making it easy to operate and observe. If installed in the main control room, it is necessary to stay away from electromagnetic interference sources such as high-voltage equipment and frequency converters, and maintain a vertical distance of at least 1 meter.

2. Probe fixation: The metal surface adopts a magnetic base, and the non-metal surface is lifted with a bracket to ensure that the probe faces the direction of the leakage source. Outdoor equipment should be installed at an angle and equipped with rain covers to prevent rainwater from entering.

3. Pipeline laying: The gas sampling pipeline is made of corrosion-resistant materials, with a length not exceeding 30 meters, to avoid bending and compression. The cable adopts RVVP shielded wire and is laid independently in conduit. It is prohibited to share conduit with power cables to prevent signal interference.

　　3、 Debugging and Calibration: Ensuring Accurate and Trustworthy Data

1. Static inspection: Before powering on, use a multimeter to check whether there is a short circuit in the probe power circuit, measure the resistance value between the signal terminal and the equipment metal shell, and eliminate the risk of leakage.

2. Dynamic testing:

① Zero point calibration: Preheat the sensor in clean air (SF6 concentration<1 μ L/L) for 30 minutes or 2 hours, and perform zero point calibration;

② Range calibration: Use standard concentration SF6 gas to pass through the probe and adjust the displayed value to be consistent with the standard gas concentration;

③ Linkage testing: Simulate a leakage scenario to verify whether the alarm signal can trigger the exhaust device and transmit it to the monitoring platform, with a response time of ≤ 30 seconds.

　　4、 Safety and Compliance: Building the Last Line of Defense

1. Explosion proof requirements: In flammable and explosive places, explosion-proof detectors should be used, which comply with the GB 3836.1-2021 standard. Explosion proof flexible pipes should be used for cable conduit;

2. Ventilation linkage: When the SF6 concentration exceeds 1000 μ L/L, the system automatically starts the exhaust device and sends a signal to the control room;

3. Personnel protection: Installation and maintenance personnel should wear gas masks and rubber gloves to avoid direct contact with high concentration SF6 gas.

The installation standards for SF6 gas online monitoring devices are constantly being refined, from the "one host per entrance" standard of State Grid to the "multi-point three-dimensional monitoring" scheme of companies such as Wefors. Through scientific layout, precise construction, and strict debugging, a monitoring network covering the entire lifecycle of equipment can be constructed, providing solid guarantees for the safe and stable operation of the power system.