Operating Procedure for SF6 Gas Density Relay Calibrator
As the level of intelligent operation and maintenance at substations continues to improve, a standardized and regulated operational system for calibrating SF₆ gas density relays has been established. As a core piece of specialized equipment for verifying high-voltage electrical equipment, the proper operation of SF₆ density relay calibrators directly determines the accuracy of calibration data and the safety of on-site operation and maintenance. Currently, the power industry has adopted a unified and mature standardized operating procedure to comprehensively ensure the reliable operation of gas-monitoring elements in high-voltage switches and GIS equipment.
Pre-calibration preparations are fundamental to ensuring calibration quality. O&M personnel must verify the relay's rated parameters, alarm thresholds, and interlock setpoints in advance; inspect the calibrator, connecting tubing, and sealing components for integrity; and remove any contaminants from the interfaces. On-site calibration without disassembly should be prioritized to prevent SF6 gas leaks and equipment wear caused by disassembly. Additionally, the temperature and humidity of the work environment must be checked to ensure operating conditions comply with industry calibration standards.
During the equipment connection phase, gas line interfaces must be properly aligned to ensure that the tubing is tightly sealed and free of kinks or damage. A comprehensive pressure-holding leak test must be performed to prevent air from entering the gas lines and causing measurement errors. Once connections are complete, the equipment automatically records the on-site ambient temperature and humidity, providing data support for subsequent conversion to the standard temperature of 20°C and eliminating the interference of ambient temperature on calibration results.
During the core calibration phase, the principle of uniform pressure adjustment must be followed, with gas pressure adjusted steadily at a low rate to simulate actual equipment operating conditions. The relay's alarm activation threshold, interlock protection threshold, and contact reset threshold are tested sequentially, with at least three sets of cyclic tests completed throughout the process to ensure data repeatability. Leveraging built-in algorithms, the instrument automatically converts the measured data to standard density parameters at 20°C, accurately calculating activation errors and hysteresis.
After calibration is complete, the pressure must be slowly released, and the piping must be dismantled in an orderly manner to restore the equipment to its original installation state. The device automatically generates a standardized calibration report, and the calibration data is archived for future reference. Industry maintenance personnel emphasize that strictly adhering to standardized operating procedures can effectively avoid human operational errors and accurately identify potential performance issues with the relays, making it a key maintenance measure for ensuring the long-term safe and stable operation of high-voltage equipment in substations.
