Online Calibration Strategy for SF6 Gas Density Relay Based on Weighing Pressure Measurement

SF6 gas has high electrical insulation strength and excellent arc-extinguishing properties, making it widely used in high-voltage equipment. However, gas leakage or liquefaction can reduce its performance, necessitating density monitoring. This paper presents an online calibration device based on balance pressure measurement and outlines the calibration process. It also analyzes the impact of factors such as the measuring balance, gravitational acceleration, cylinder friction, and installation alignment on calibration accuracy. To address uncertainty in the stabilization time of the cylinder gas temperature, a simulation model was created to observe the temperature equilibrium. Furthermore, power consumption analysis of the test device was conducted under different calibration cycles. The experimental results confirm the effectiveness of this calibration strategy.